http://hdl.handle.net/10023/32 2013-05-22T17:05:56Z http://hdl.handle.net/10023/3514 Abstract: The pro-sociality of humans is manifested by the existence of cooperation in levels not common with any other species. Previous studies suggest that snap judgements of individuals are enough to determine if someone is a potential partner for cooperation. In addition to the often studied facial characteristics affecting cooperativeness and trustworthiness attribution (kin resemblance; attractiveness and emotional expression), the experimental work reported here examined the influence of head posture; gaze direction and skin colour on the attribution of trustworthiness and cooperation. A slightly tilted head (less than 3° downward) increased the perception of cooperativeness, especially for male and hostile looking faces. The importance of head tilt increased with decreased self-assessed dominance. Furthermore, even though some evidence that the effect of head posture is independent of gaze direction was found, gaze direction was also a strong indicator of cooperative intentions. Direct gaze and gaze slightly looking down (3°) were perceived as more cooperative than deviations of gaze outside this range (3° up or 6°- 9° down). Skin colour, a putative cue to current health status, was also found to impact on trustworthiness perception with a healthy skin colour increasing trustworthiness ratings. Additionally, as cooperative and trust decisions are vital for survival and social interactions, decisions based on facial appearance are made quickly and automatically as demonstrated by a trustworthiness modulation on an early face related component with 170 ms of exposure. Collectively, these findings suggest that facial characteristics employed to infer trust and cooperativeness help the observer to assess the motives and intentions of the individuals and assist the choice of partners that will lead to increased benefits and reduced costs in collaborative actions. Such considerations fit well with the evolutionary theory of cooperation as reciprocated social exchange. Description: Electronic version excludes embargoed material (Chapters 2-6) 2013-06-25T00:00:00Z Dzhelyova, Milena P. The pro-sociality of humans is manifested by the existence of cooperation in levels not common with any other species. Previous studies suggest that snap judgements of individuals are enough to determine if someone is a potential partner for cooperation. In addition to the often studied facial characteristics affecting cooperativeness and trustworthiness attribution (kin resemblance; attractiveness and emotional expression), the experimental work reported here examined the influence of head posture; gaze direction and skin colour on the attribution of trustworthiness and cooperation. A slightly tilted head (less than 3° downward) increased the perception of cooperativeness, especially for male and hostile looking faces. The importance of head tilt increased with decreased self-assessed dominance. Furthermore, even though some evidence that the effect of head posture is independent of gaze direction was found, gaze direction was also a strong indicator of cooperative intentions. Direct gaze and gaze slightly looking down (3°) were perceived as more cooperative than deviations of gaze outside this range (3° up or 6°- 9° down). Skin colour, a putative cue to current health status, was also found to impact on trustworthiness perception with a healthy skin colour increasing trustworthiness ratings. Additionally, as cooperative and trust decisions are vital for survival and social interactions, decisions based on facial appearance are made quickly and automatically as demonstrated by a trustworthiness modulation on an early face related component with 170 ms of exposure. Collectively, these findings suggest that facial characteristics employed to infer trust and cooperativeness help the observer to assess the motives and intentions of the individuals and assist the choice of partners that will lead to increased benefits and reduced costs in collaborative actions. Such considerations fit well with the evolutionary theory of cooperation as reciprocated social exchange. http://hdl.handle.net/10023/3495 Abstract: Variation in methods and measures, resulting in past dispute over the existence of population handedness in nonhuman great apes, has impeded progress into the origins of human right-handedness and how it relates to the human hallmark of language. Pooling evidence from behavioral studies, neuroimaging and neuroanatomy, we evaluate data on manual and cerebral laterality in humans and other apes engaged in a range of manipulative tasks and in gestural communication. A simplistic human/animal partition is no longer tenable, and we review four (nonexclusive) possible drivers for the origin of population-level right-handedness: skilled manipulative activity, as in tool use; communicative gestures; organizational complexity of action, in particular hierarchical structure; and the role of intentionality in goal-directed action. Fully testing these hypotheses will require developmental and evolutionary evidence as well as modern neuroimaging data. 2013-01-01T00:00:00Z Cochet, Hélène Byrne, Richard William Variation in methods and measures, resulting in past dispute over the existence of population handedness in nonhuman great apes, has impeded progress into the origins of human right-handedness and how it relates to the human hallmark of language. Pooling evidence from behavioral studies, neuroimaging and neuroanatomy, we evaluate data on manual and cerebral laterality in humans and other apes engaged in a range of manipulative tasks and in gestural communication. A simplistic human/animal partition is no longer tenable, and we review four (nonexclusive) possible drivers for the origin of population-level right-handedness: skilled manipulative activity, as in tool use; communicative gestures; organizational complexity of action, in particular hierarchical structure; and the role of intentionality in goal-directed action. Fully testing these hypotheses will require developmental and evolutionary evidence as well as modern neuroimaging data. http://hdl.handle.net/10023/3493 Abstract: Explanations based in attribution theory claim that strong external controls such as parental restrictiveness and punishment undermine moral internalization. In contrast, three studies provide evidence that parental punishment does socialize morality, but of a particular sort: a morality focused on prohibitions (i.e., proscriptive orientation), rather than positive obligations (i.e., prescriptive orientation). Study 1 found young adults’ accounts of parental restrictiveness and punishment activated their sensitivity to prohibitions and predicted a proscriptive orientation. Consistent with the greater potency of temptations for proscriptively-oriented children, as well as past research linking shame to proscriptive morality, Study 2 found that restrictive parenting was also associated with greater suppression of temptations. Finally, Studies 3a and 3b found that suppressing these immoral thoughts is paradoxically harder for those with strong proscriptive orientations; more specifically, priming a proscriptive (versus prescriptive) orientation and inducing mental suppression of “immoral” thoughts led to the most ego depletion for those with restrictive parents. Overall, individuals who had restrictive parents had the lowest self-regulatory ability to resist their “immoral” temptations after prohibitions were activated. In contrast to common attributional explanations, these studies suggest that harsh external control by parents does not undercut moral socialization, but rather undermines individuals’ ability to resist temptation. 2013-01-01T00:00:00Z Sheikh, Sana Janoff-Bulman, Ronnie Explanations based in attribution theory claim that strong external controls such as parental restrictiveness and punishment undermine moral internalization. In contrast, three studies provide evidence that parental punishment does socialize morality, but of a particular sort: a morality focused on prohibitions (i.e., proscriptive orientation), rather than positive obligations (i.e., prescriptive orientation). Study 1 found young adults’ accounts of parental restrictiveness and punishment activated their sensitivity to prohibitions and predicted a proscriptive orientation. Consistent with the greater potency of temptations for proscriptively-oriented children, as well as past research linking shame to proscriptive morality, Study 2 found that restrictive parenting was also associated with greater suppression of temptations. Finally, Studies 3a and 3b found that suppressing these immoral thoughts is paradoxically harder for those with strong proscriptive orientations; more specifically, priming a proscriptive (versus prescriptive) orientation and inducing mental suppression of “immoral” thoughts led to the most ego depletion for those with restrictive parents. Overall, individuals who had restrictive parents had the lowest self-regulatory ability to resist their “immoral” temptations after prohibitions were activated. In contrast to common attributional explanations, these studies suggest that harsh external control by parents does not undercut moral socialization, but rather undermines individuals’ ability to resist temptation. http://hdl.handle.net/10023/3459 Abstract: Episodic memory incorporates information about specific events or occasions including spatial locations and the contextual features of the environment in which the event took place. It has been modeled in rats using spontaneous exploration of novel configurations of objects, their locations, and the contexts in which they are presented. While we have a detailed understanding of how spatial location is processed in the brain relatively little is known about where the nonspatial contextual components of episodic memory are processed. Initial experiments measured c-fos expression during an object-context recognition (OCR) task to examine which networks within the brain process contextual features of an event. Increased c-fos expression was found in the lateral entorhinal cortex (LEC; a major hippocampal afferent) during OCR relative to control conditions. In a subsequent experiment it was demonstrated that rats with lesions of LEC were unable to recognize object-context associations yet showed normal object recognition and normal context recognition. These data suggest that contextual features of the environment are integrated with object identity in LEC and demonstrate that recognition of such object-context associations requires the LEC. This is consistent with the suggestion that contextual features of an event are processed in LEC and that this information is combined with spatial information from medial entorhinal cortex to form episodic memory in the hippocampus. © 2013 Wiley Periodicals, Inc. 2013-01-01T00:00:00Z Wilson, David Ian Greig Langston, Rosamund F. Schlesiger, Magdalene I. Wagner, Monica Watanabe, Sakurako Ainge, James Alexander Episodic memory incorporates information about specific events or occasions including spatial locations and the contextual features of the environment in which the event took place. It has been modeled in rats using spontaneous exploration of novel configurations of objects, their locations, and the contexts in which they are presented. While we have a detailed understanding of how spatial location is processed in the brain relatively little is known about where the nonspatial contextual components of episodic memory are processed. Initial experiments measured c-fos expression during an object-context recognition (OCR) task to examine which networks within the brain process contextual features of an event. Increased c-fos expression was found in the lateral entorhinal cortex (LEC; a major hippocampal afferent) during OCR relative to control conditions. In a subsequent experiment it was demonstrated that rats with lesions of LEC were unable to recognize object-context associations yet showed normal object recognition and normal context recognition. These data suggest that contextual features of the environment are integrated with object identity in LEC and demonstrate that recognition of such object-context associations requires the LEC. This is consistent with the suggestion that contextual features of an event are processed in LEC and that this information is combined with spatial information from medial entorhinal cortex to form episodic memory in the hippocampus. © 2013 Wiley Periodicals, Inc. http://hdl.handle.net/10023/3446 Abstract: The physical complications of Type 1 diabetes mellitus (T1DM) have been understood as an accelerated ageing process (Morley, 2008). Do people with T1DM also experience accelerated cognitive and brain ageing? Using findings from research of the normal cognitive and brain ageing process and conceptualized in theories of the functional brain changes in cognitive ageing, a combination of cognitive testing and functional magnetic resonance imaging (fMRI) techniques were used to evaluate evidence of accelerated cognitive and brain ageing in middle-aged adults with T1DM. The first part of this thesis comprises a cognitive study of 94 adults (≥ 45 years of age) with long duration (≥ 10 years) of T1DM. Participants completed cognitive assessment and questionnaires on general mood and feelings about living with diabetes. Findings highlighted the importance of microvascular disease (specifically retinopathy) as an independent predictor of cognitive function. The incidence and predictors of mild cognitive impairment (MCI) were then explored. Results indicate a higher percentage of the group met criteria for MCI than expected based on incidence rates in the general population, providing initial evidence of accelerated cognitive ageing. Psychological factors were explored next. The relationship between the measures of well-being, diabetes health, and cognitive function highlighted the need for attention to patient’s psychological well-being in diabetes care. Finally, a subgroup of 30 participants between the ages of 45 and 65 who differed on severity of retinopathy were selected to take part in an fMRI study. Blood oxygen level dependent (BOLD) activity was evaluated while participants were engaged in cognitive tasks and during rest. The findings provided evidence that the pattern of BOLD activation and functional connectivity for those with high severity of retinopathy are similar to patterns found in adults over the age of 65. In line with the theories of cognitive ageing, functional brain changes appear to maintain a level of cognitive function. Evidence of accelerated brain ageing in this primarily middle-aged group, emphasizes the importance of treatments and regimens to prevent or minimize microvascular complications.   2013-06-25T00:00:00Z Johnston, Harriet N. The physical complications of Type 1 diabetes mellitus (T1DM) have been understood as an accelerated ageing process (Morley, 2008). Do people with T1DM also experience accelerated cognitive and brain ageing? Using findings from research of the normal cognitive and brain ageing process and conceptualized in theories of the functional brain changes in cognitive ageing, a combination of cognitive testing and functional magnetic resonance imaging (fMRI) techniques were used to evaluate evidence of accelerated cognitive and brain ageing in middle-aged adults with T1DM. The first part of this thesis comprises a cognitive study of 94 adults (≥ 45 years of age) with long duration (≥ 10 years) of T1DM. Participants completed cognitive assessment and questionnaires on general mood and feelings about living with diabetes. Findings highlighted the importance of microvascular disease (specifically retinopathy) as an independent predictor of cognitive function. The incidence and predictors of mild cognitive impairment (MCI) were then explored. Results indicate a higher percentage of the group met criteria for MCI than expected based on incidence rates in the general population, providing initial evidence of accelerated cognitive ageing. Psychological factors were explored next. The relationship between the measures of well-being, diabetes health, and cognitive function highlighted the need for attention to patient’s psychological well-being in diabetes care. Finally, a subgroup of 30 participants between the ages of 45 and 65 who differed on severity of retinopathy were selected to take part in an fMRI study. Blood oxygen level dependent (BOLD) activity was evaluated while participants were engaged in cognitive tasks and during rest. The findings provided evidence that the pattern of BOLD activation and functional connectivity for those with high severity of retinopathy are similar to patterns found in adults over the age of 65. In line with the theories of cognitive ageing, functional brain changes appear to maintain a level of cognitive function. Evidence of accelerated brain ageing in this primarily middle-aged group, emphasizes the importance of treatments and regimens to prevent or minimize microvascular complications.   http://hdl.handle.net/10023/3432 Abstract: Numerous researchers have examined the effects of skin condition, including texture and color, on the perception of health, age, and attractiveness in human faces. They have focused on facial color distribution, homogeneity of pigmentation, or skin quality. We here investigate the role of overall skin color in determining perceptions of health from faces by allowing participants to manipulate the skin portions of color-calibrated Caucasian face photographs along CIELab color axes. To enhance healthy appearance, participants increased skin redness (a*), providing additional support for previous findings that skin blood color enhances the healthy appearance of faces. Participants also increased skin yellowness (b*) and lightness (L*), suggesting a role for high carotenoid and low melanin coloration in the healthy appearance of faces. The color preferences described here resemble the red and yellow color cues to health displayed by many species of nonhuman animals. Description: I stephen was funded by a BBSRC Studentship. M Stirrat was funded by an EPSRC Studentship. 2009-12-01T00:00:00Z Stephen, Ian David Law Smith, Miriam Jane Stirrat, Michael Robert Perrett, David Ian Numerous researchers have examined the effects of skin condition, including texture and color, on the perception of health, age, and attractiveness in human faces. They have focused on facial color distribution, homogeneity of pigmentation, or skin quality. We here investigate the role of overall skin color in determining perceptions of health from faces by allowing participants to manipulate the skin portions of color-calibrated Caucasian face photographs along CIELab color axes. To enhance healthy appearance, participants increased skin redness (a*), providing additional support for previous findings that skin blood color enhances the healthy appearance of faces. Participants also increased skin yellowness (b*) and lightness (L*), suggesting a role for high carotenoid and low melanin coloration in the healthy appearance of faces. The color preferences described here resemble the red and yellow color cues to health displayed by many species of nonhuman animals. http://hdl.handle.net/10023/3431 Abstract: Skin blood perfusion and oxygenation depends upon cardiovascular, hormonal and circulatory health in humans and provides socio-sexual signals of underlying physiology, dominance and reproductive status in some primates. We allowed participants to manipulate colour calibrated facial photographs along empirically-measured oxygenated and deoxygenated blood colour axes both separately and simultaneously, to optimise healthy appearance. Participants increased skin blood colour, particularly oxygenated, above basal levels to optimise healthy appearance. We show, therefore, that skin blood perfusion and oxygenation influence perceived health in a way that may be important to mate choice. Description: I Stephen was funded by a BBSRC Studentship. 2009-04-01T00:00:00Z Stephen, Ian David Coetzee, Vinet Law Smith, Miriam Jane Perrett, David Ian Skin blood perfusion and oxygenation depends upon cardiovascular, hormonal and circulatory health in humans and provides socio-sexual signals of underlying physiology, dominance and reproductive status in some primates. We allowed participants to manipulate colour calibrated facial photographs along empirically-measured oxygenated and deoxygenated blood colour axes both separately and simultaneously, to optimise healthy appearance. Participants increased skin blood colour, particularly oxygenated, above basal levels to optimise healthy appearance. We show, therefore, that skin blood perfusion and oxygenation influence perceived health in a way that may be important to mate choice. http://hdl.handle.net/10023/3428 Abstract: Background: Fruit and vegetable consumption and ingestion of carotenoids have been found to be associated with human skin-color (yellowness) in a recent cross-sectional study. This carotenoid-based coloration contributes beneficially to the appearance of health in humans and is held to be a sexually selected cue of condition in other species. Methodology and Principal Findings: Here we investigate the effects of fruit and vegetable consumption on skin-color longitudinally to determine the magnitude and duration of diet change required to change skin-color perceptibly. Diet and skin-color were recorded at baseline and after three and six weeks, in a group of 35 individuals who were without makeup, self-tanning agents and/or recent intensive UV exposure. Six-week changes in fruit and vegetable consumption were significantly correlated with changes in skin redness and yellowness over this period, and diet-linked skin reflectance changes were significantly associated with the spectral absorption of carotenoids and not melanin. We also used psychophysical methods to investigate the minimum color change required to confer perceptibly healthier and more attractive skin-coloration. Modest dietary changes are required to enhance apparent health (2.91 portions per day) and attractiveness (3.30 portions). Conclusions: Increased fruit and vegetable consumption confers measurable and perceptibly beneficial effects on Caucasian skin appearance within six weeks. This effect could potentially be used as a motivational tool in dietary intervention. Description: R Whitehead was funded by an ESRC Studentship. 2012-03-07T00:00:00Z Whitehead, Ross Re, Daniel Xiao, Dengke Ozakinci, Gozde Perrett, David Ian Background: Fruit and vegetable consumption and ingestion of carotenoids have been found to be associated with human skin-color (yellowness) in a recent cross-sectional study. This carotenoid-based coloration contributes beneficially to the appearance of health in humans and is held to be a sexually selected cue of condition in other species. Methodology and Principal Findings: Here we investigate the effects of fruit and vegetable consumption on skin-color longitudinally to determine the magnitude and duration of diet change required to change skin-color perceptibly. Diet and skin-color were recorded at baseline and after three and six weeks, in a group of 35 individuals who were without makeup, self-tanning agents and/or recent intensive UV exposure. Six-week changes in fruit and vegetable consumption were significantly correlated with changes in skin redness and yellowness over this period, and diet-linked skin reflectance changes were significantly associated with the spectral absorption of carotenoids and not melanin. We also used psychophysical methods to investigate the minimum color change required to confer perceptibly healthier and more attractive skin-coloration. Modest dietary changes are required to enhance apparent health (2.91 portions per day) and attractiveness (3.30 portions). Conclusions: Increased fruit and vegetable consumption confers measurable and perceptibly beneficial effects on Caucasian skin appearance within six weeks. This effect could potentially be used as a motivational tool in dietary intervention. http://hdl.handle.net/10023/3393 Abstract: Moralization is the process whereby preferences are converted to values (Rozin, 1999). Two studies used an embodied metaphor approach, in which moral metaphors are grounded in one’s sense of physical cleanliness, to investigate whether restrained eating practices are moralized among women. Specifically, we predicted that the regulation of food intake by women is embodied in their feelings of physical cleanliness. Study 1 found that failures of restrained eating (i.e., overeating) increased accessibility of physical cleanliness-related words for women, but not men. Study 2 found that increased negative moral emotions fully mediated the effect of overeating on a desire for physical cleanliness. Overall, the studies argue for the importance of morality in restrained eating and in the central role of emotions in the embodiment of cognitive metaphors. 2013-05-01T00:00:00Z Sheikh, Sana Botindari, Lucia White, Emma Moralization is the process whereby preferences are converted to values (Rozin, 1999). Two studies used an embodied metaphor approach, in which moral metaphors are grounded in one’s sense of physical cleanliness, to investigate whether restrained eating practices are moralized among women. Specifically, we predicted that the regulation of food intake by women is embodied in their feelings of physical cleanliness. Study 1 found that failures of restrained eating (i.e., overeating) increased accessibility of physical cleanliness-related words for women, but not men. Study 2 found that increased negative moral emotions fully mediated the effect of overeating on a desire for physical cleanliness. Overall, the studies argue for the importance of morality in restrained eating and in the central role of emotions in the embodiment of cognitive metaphors. http://hdl.handle.net/10023/3382 Abstract: Staff working directly with adults challenging behaviours in learning disability services need to be very good at what they do. They also need to want to do the job. A theory-practice gap exists, however, between what is known about effective, evidence-based approaches and whether and how these are used in person-centred, community services. Many front line staff working with people with the most serious challenging behaviours do not have the skills to implement programmes to change behaviour. This discussion paper reviews workforce development in the context of clinical and service guidelines and asks whether the legitimate purview of frontline staff is a balance of treating challenging behaviour, managing it or to simply coping with it on a daily basis, whilst maintaining the best quality of life possible for service users. 2010-09-01T00:00:00Z Campbell, Martin Staff working directly with adults challenging behaviours in learning disability services need to be very good at what they do. They also need to want to do the job. A theory-practice gap exists, however, between what is known about effective, evidence-based approaches and whether and how these are used in person-centred, community services. Many front line staff working with people with the most serious challenging behaviours do not have the skills to implement programmes to change behaviour. This discussion paper reviews workforce development in the context of clinical and service guidelines and asks whether the legitimate purview of frontline staff is a balance of treating challenging behaviour, managing it or to simply coping with it on a daily basis, whilst maintaining the best quality of life possible for service users. http://hdl.handle.net/10023/3381 Description: Special Issue: Safeguarding adults at risk of harm in Scotland. 2012-01-01T00:00:00Z Campbell, Martin Penhale, Bridget http://hdl.handle.net/10023/3380 Abstract: Reducing health inequalities is a key priority for the Scottish Government. Health authorities are expected to meet quality targets. The involvement of people with learning disabilities in health service review teams has been one of the initiatives used in by NHS Quality Improvement Scotland to empower patients and improve health services. This paper describes this initiative, how it was planned, and an evaluation by health staff, carers and people with learning disabilities. Recommendations are made to ensure the future success of this type of initiative in Scotland and elsewhere. This initiative was evaluated positively and tested traditional assumptions, challenging the power imbalance in patient-provider relationships. The theory and the practice of including people with learning disabilities as “expert patient” reviewers are discussed. 2010-03-01T00:00:00Z Campbell, Martin Martin, M Reducing health inequalities is a key priority for the Scottish Government. Health authorities are expected to meet quality targets. The involvement of people with learning disabilities in health service review teams has been one of the initiatives used in by NHS Quality Improvement Scotland to empower patients and improve health services. This paper describes this initiative, how it was planned, and an evaluation by health staff, carers and people with learning disabilities. Recommendations are made to ensure the future success of this type of initiative in Scotland and elsewhere. This initiative was evaluated positively and tested traditional assumptions, challenging the power imbalance in patient-provider relationships. The theory and the practice of including people with learning disabilities as “expert patient” reviewers are discussed. http://hdl.handle.net/10023/3379 Abstract: A new risk assessment tool, Assessment of Interpersonal Risk (AIR), was piloted and evaluated to measure risk factors and compatibility between individuals living in an assessment and treatment unit in one NHS area. The adults with learning disabilities in this unit had severe and enduring mental health problems and/or behaviour that is severely challenging. The aims of this small-scale research project were to estimate the reciprocal risk to and from each individual across five main risk domains and to enhance professional judgement to make defensible decisions about interpersonal risk. Data were recorded on incidents involving five individuals over a period of 6 months. Individual Rating Profiles were incorporated into existing Individual Risk Management Plans, together with interpersonal profiles, recording risk evaluations between named individuals across the five risk domains. Results showed that the AIR tool may be a useful addition to existing effective risk management, to inform assessments and future discharge planning. Description: This article is a report on a research project funded by the Knowledge Transfer Partnership. This research was a joint project with NHS Fife. The accelerated long-stay Learning Disability Hospital closure programme in Scotland throughout the late 1990s and from 2000 onwards, resulted in the movement of residents both within and out-with these Hospitals to either community based housing models or to community based In-patient services. The legacy and impact of this residential service re-provision was that individuals experienced changes in those they lived with, and those who supported them. This process took place against the back-drop and dynamic of associated changes in environmental, procedural, situational and interpersonal risk. It was in recognition of the challenge that this change programme presented to care services in terms of defensible risk assessment and management that the Assessment of Interpersonal Risk tool was developed. 2012-01-01T00:00:00Z Campbell, Martin McCue, Michael A new risk assessment tool, Assessment of Interpersonal Risk (AIR), was piloted and evaluated to measure risk factors and compatibility between individuals living in an assessment and treatment unit in one NHS area. The adults with learning disabilities in this unit had severe and enduring mental health problems and/or behaviour that is severely challenging. The aims of this small-scale research project were to estimate the reciprocal risk to and from each individual across five main risk domains and to enhance professional judgement to make defensible decisions about interpersonal risk. Data were recorded on incidents involving five individuals over a period of 6 months. Individual Rating Profiles were incorporated into existing Individual Risk Management Plans, together with interpersonal profiles, recording risk evaluations between named individuals across the five risk domains. Results showed that the AIR tool may be a useful addition to existing effective risk management, to inform assessments and future discharge planning. http://hdl.handle.net/10023/3378 Abstract: Purpose: To evaluate understanding and knowledge of the Adult Support and Protection (Scotland) Act 2007 in a sample of community nurses working in learning disability services in Scotland. Design: Ten community nurses who worked in learning disability services in one NHS area were tested at two time points, four months apart using a questionnaire designed for this study by researchers and practitioners. Level of previous national training in the Adult Support and Protection Act, and length of time working with people with learning disabilities were recorded. Three domains of adult protection were included in the questionnaire: Principles of the Act and definitions; Adults at Risk of Harm; Protection, Assessment, Removal and Banning Orders. Findings: Questionnaire scores varied widely overall and across the three domains. There was no correlation between individual scores and training or length of work experience. The level of knowledge was below what might have been expected for this group, given the level of training and experience. Carefully designed verification of the impact of nationally approved Adult Support and Protection training is needed. Originality/Value: There is an absence of research in evaluating the impact of the approved Scottish Government training materials on staff knowledge and understanding of the 2007 Act, with staff attendance being taken as the main measure of training compliance. This was a small scale, pilot study and recommendations are made for the scope and methods of evaluation. Description: This research was funded from a grant from Queens Nursing Institute Scotland. Special Issue: Safeguarding adults at risk of harm in Scotland. Guest editor(s): Martin Campbell, James Hogg and Bridget Penhale. 2012-08-06T00:00:00Z Campbell, Martin Chamberlin, Dionne Purpose: To evaluate understanding and knowledge of the Adult Support and Protection (Scotland) Act 2007 in a sample of community nurses working in learning disability services in Scotland. Design: Ten community nurses who worked in learning disability services in one NHS area were tested at two time points, four months apart using a questionnaire designed for this study by researchers and practitioners. Level of previous national training in the Adult Support and Protection Act, and length of time working with people with learning disabilities were recorded. Three domains of adult protection were included in the questionnaire: Principles of the Act and definitions; Adults at Risk of Harm; Protection, Assessment, Removal and Banning Orders. Findings: Questionnaire scores varied widely overall and across the three domains. There was no correlation between individual scores and training or length of work experience. The level of knowledge was below what might have been expected for this group, given the level of training and experience. Carefully designed verification of the impact of nationally approved Adult Support and Protection training is needed. Originality/Value: There is an absence of research in evaluating the impact of the approved Scottish Government training materials on staff knowledge and understanding of the 2007 Act, with staff attendance being taken as the main measure of training compliance. This was a small scale, pilot study and recommendations are made for the scope and methods of evaluation. http://hdl.handle.net/10023/3375 Abstract: Staff working directly with people who have challenging behaviour in learning disability services need to be D good at what they do. These staff are trained by their employers to manage and to treat challenging behaviours and to improve the quality of life of people in their care. While such training is generally well evaluated by care staff, there is limited evidence that training alone changes poor attitudes or improves staff performance. Training has not been linked to quality of outcomes for service users. From research on treating challenging behaviour, achieving maintenance of behavioural gains after treatment has been discontinued is the exception rather than the rule. Can the same be said for maintaining gains achieved through staff training in the area of challenging behaviour? This discussion article reviews the value of training for staff working with people with challenging behaviour. 2007-06-01T00:00:00Z Campbell, Martin Staff working directly with people who have challenging behaviour in learning disability services need to be D good at what they do. These staff are trained by their employers to manage and to treat challenging behaviours and to improve the quality of life of people in their care. While such training is generally well evaluated by care staff, there is limited evidence that training alone changes poor attitudes or improves staff performance. Training has not been linked to quality of outcomes for service users. From research on treating challenging behaviour, achieving maintenance of behavioural gains after treatment has been discontinued is the exception rather than the rule. Can the same be said for maintaining gains achieved through staff training in the area of challenging behaviour? This discussion article reviews the value of training for staff working with people with challenging behaviour. http://hdl.handle.net/10023/3371 Abstract: Poor diet precipitates significant social and economic burden, necessitating effective and economical dietary intervention strategies. Current population-level campaigns provide guidelines for living healthily and focus on the impact of lifestyle on chronic disease risk. Behavioural interventions which capitalise on individuals’ existing cognitions are likely to be more effective. A programme of work is presented here which evaluates the feasibility and efficacy of an appearance-based dietary intervention approach. This project aims to improve fruit and vegetable consumption by illustrating the associated benefits to skin appearance. The impact of fruit and vegetable consumption on skin colour is assessed (Chapter 6), corroborating previous between-subjects evidence which finds that dermal yellowness (CIE b*) is positively associated with fruit and vegetable intake. This work also discovers that modest within-subject dietary change is sufficient to perceptibly alter skin colour within six weeks (Chapter 7). Perceptual preferences are examined (Chapters 5 to 9), finding that optimally healthy skin colouration is that associated with increased fruit and vegetable consumption. Two behavioural intervention trials are conducted (Chapters 6 and 9) to evaluate whether visualising the impact of fruit and vegetable consumption on skin colour motivates dietary improvement. Relative to control groups, participants receiving an appearance-based intervention (in which the above effects are illustrated and explained) reported improvements in diet, particularly when illustrations were performed upon images of one’s own face. It may be valuable to disseminate such an intervention at a population level, though a number of further longitudinal studies are necessary to determine the wider effectiveness of this approach. 2013-06-25T00:00:00Z Whitehead, Ross David Poor diet precipitates significant social and economic burden, necessitating effective and economical dietary intervention strategies. Current population-level campaigns provide guidelines for living healthily and focus on the impact of lifestyle on chronic disease risk. Behavioural interventions which capitalise on individuals’ existing cognitions are likely to be more effective. A programme of work is presented here which evaluates the feasibility and efficacy of an appearance-based dietary intervention approach. This project aims to improve fruit and vegetable consumption by illustrating the associated benefits to skin appearance. The impact of fruit and vegetable consumption on skin colour is assessed (Chapter 6), corroborating previous between-subjects evidence which finds that dermal yellowness (CIE b*) is positively associated with fruit and vegetable intake. This work also discovers that modest within-subject dietary change is sufficient to perceptibly alter skin colour within six weeks (Chapter 7). Perceptual preferences are examined (Chapters 5 to 9), finding that optimally healthy skin colouration is that associated with increased fruit and vegetable consumption. Two behavioural intervention trials are conducted (Chapters 6 and 9) to evaluate whether visualising the impact of fruit and vegetable consumption on skin colour motivates dietary improvement. Relative to control groups, participants receiving an appearance-based intervention (in which the above effects are illustrated and explained) reported improvements in diet, particularly when illustrations were performed upon images of one’s own face. It may be valuable to disseminate such an intervention at a population level, though a number of further longitudinal studies are necessary to determine the wider effectiveness of this approach. http://hdl.handle.net/10023/3368 Abstract: The research aims of this thesis are to investigate the attention cues available to and used by apes, especially gorillas (Gorilla gorilla), to ascertain the direction of conspecific attention during social interactions with a special reference to social play. Minimal research has been conducted on the role of attention cues - eye gaze, head, and body orientation - to regulate natural social interactions, such as social play, in non-human primates. This thesis begins with an investigation of the "cooperative eye hypothesis", which poses that humans have evolved a unique white sclera adaptation for advertising and detecting gaze direction. Chapter 2 reports the existence of a natural white sclera variation in a proportion of gorilla eyes - contradicting the widely held assumption that white sclera is an exclusively human characteristic - and analyzes the presence of white sclera in relation to other morphological changes in the human eye. The study concludes that the morphological elongation of the eye might be a more important and unique change than the white sclera coloration. Chapter 3 experimentally explores the contribution of white sclera in both great ape and human eye gaze to the perception of gaze direction detection by human observers. This chapter concludes that although white sclera contributes to the accuracy and speed of gaze direction detection (an assumption that this thesis has put to experimental test for the first time), this merely adds to the already efficient gaze cues available in the eye areas of the ape face. Chapter 4 investigates the role of eye gaze, head, and body orientations during gorilla social play behavior, and more specifically, introduces a novel analysis of "vigilance periods" (VPs), in which gorillas may use the interaction between attention cues to gauge the attention and intentions of play partners to successfully navigate play. The final study (Chapter 5) complements Chapter 4 and investigates the role of gorilla postures, behaviors, and movements during changes in attentional cue orientations. This chapter concludes that gorillas often engage in physical rest during VPs but maintain attentional engagement and can assemble and impart socially relevant information based on the behaviors, movements, and attention orientations of their partner. Together, these studies suggest that attention orientation is conveyed and assessed by gorillas through a variety of interacting cues to navigate and modify social play interactions. 2013-06-25T00:00:00Z Mayhew, Jessica A. The research aims of this thesis are to investigate the attention cues available to and used by apes, especially gorillas (Gorilla gorilla), to ascertain the direction of conspecific attention during social interactions with a special reference to social play. Minimal research has been conducted on the role of attention cues - eye gaze, head, and body orientation - to regulate natural social interactions, such as social play, in non-human primates. This thesis begins with an investigation of the "cooperative eye hypothesis", which poses that humans have evolved a unique white sclera adaptation for advertising and detecting gaze direction. Chapter 2 reports the existence of a natural white sclera variation in a proportion of gorilla eyes - contradicting the widely held assumption that white sclera is an exclusively human characteristic - and analyzes the presence of white sclera in relation to other morphological changes in the human eye. The study concludes that the morphological elongation of the eye might be a more important and unique change than the white sclera coloration. Chapter 3 experimentally explores the contribution of white sclera in both great ape and human eye gaze to the perception of gaze direction detection by human observers. This chapter concludes that although white sclera contributes to the accuracy and speed of gaze direction detection (an assumption that this thesis has put to experimental test for the first time), this merely adds to the already efficient gaze cues available in the eye areas of the ape face. Chapter 4 investigates the role of eye gaze, head, and body orientations during gorilla social play behavior, and more specifically, introduces a novel analysis of "vigilance periods" (VPs), in which gorillas may use the interaction between attention cues to gauge the attention and intentions of play partners to successfully navigate play. The final study (Chapter 5) complements Chapter 4 and investigates the role of gorilla postures, behaviors, and movements during changes in attentional cue orientations. This chapter concludes that gorillas often engage in physical rest during VPs but maintain attentional engagement and can assemble and impart socially relevant information based on the behaviors, movements, and attention orientations of their partner. Together, these studies suggest that attention orientation is conveyed and assessed by gorillas through a variety of interacting cues to navigate and modify social play interactions. http://hdl.handle.net/10023/3365 Abstract: Executive control is a vital cognitive function that facilitates the focussing and shifting of attention, planning and working towards a goal, ignoring distractions, and flexibly responding to novel situations. Disruptions to executive control are seen in many psychiatric and neurodegenerative disorders, as well as healthy ageing, which can be profoundly detrimental. Despite having many effective and well-validated methodologies for detecting and quantifying these deficits, there are very few treatments — pharmacological or otherwise — for ameliorating executive dysfunction. This lack of progress can partly be blamed on difficulties associated with identifying drugs that enhance cognition in preclinical research. The work in this thesis aimed to expand our understanding of executive dysfunction — as well as the tasks that measure it — in rats. In results presented in chapter three, middle-aged rats demonstrated impaired reversal learning on the standard attentional set-shifting task, but this was treatable with a novel drug targeting the N-methyl-D-aspartate receptor. The age impairments seen in this experiment were similar to those previously found in young rats with orbital prefrontal cortex (OFC) lesions. The results of chapter four expanded on this similarity to show that, along with reversal deficits, young OFC-lesioned rats are impaired at forming attentional sets when tested on a modified task. In chapter five, another modified set-shifting task revealed that middle-aged rats also suffer from impaired set-formation, but their reversal learning impairments only manifest before attentional set has been formed — not after. Finally, in chapter six, the putative cognitive enhancer modafinil was found to exacerbate middle-aged rats’ reversal learning deficit, but it also enhanced their subsequent ability to form attentional set. These experiments reveal that modifying the rat attentional set-shifting task can sometimes make it a more effective tool for testing cognitive enhancers in preclinical settings. 2013-06-25T00:00:00Z Chase, E. Alexander Executive control is a vital cognitive function that facilitates the focussing and shifting of attention, planning and working towards a goal, ignoring distractions, and flexibly responding to novel situations. Disruptions to executive control are seen in many psychiatric and neurodegenerative disorders, as well as healthy ageing, which can be profoundly detrimental. Despite having many effective and well-validated methodologies for detecting and quantifying these deficits, there are very few treatments — pharmacological or otherwise — for ameliorating executive dysfunction. This lack of progress can partly be blamed on difficulties associated with identifying drugs that enhance cognition in preclinical research. The work in this thesis aimed to expand our understanding of executive dysfunction — as well as the tasks that measure it — in rats. In results presented in chapter three, middle-aged rats demonstrated impaired reversal learning on the standard attentional set-shifting task, but this was treatable with a novel drug targeting the N-methyl-D-aspartate receptor. The age impairments seen in this experiment were similar to those previously found in young rats with orbital prefrontal cortex (OFC) lesions. The results of chapter four expanded on this similarity to show that, along with reversal deficits, young OFC-lesioned rats are impaired at forming attentional sets when tested on a modified task. In chapter five, another modified set-shifting task revealed that middle-aged rats also suffer from impaired set-formation, but their reversal learning impairments only manifest before attentional set has been formed — not after. Finally, in chapter six, the putative cognitive enhancer modafinil was found to exacerbate middle-aged rats’ reversal learning deficit, but it also enhanced their subsequent ability to form attentional set. These experiments reveal that modifying the rat attentional set-shifting task can sometimes make it a more effective tool for testing cognitive enhancers in preclinical settings. http://hdl.handle.net/10023/3357 Abstract: Summary Alternating contractions of antagonistic muscle groups during locomotion are generated by spinal “half-center” networks coupled in antiphase by reciprocal inhibition. It is widely thought that reciprocal inhibition only coordinates the activity of these muscles. We have devised two methods to rapidly and selectively silence neurons on just one side of Xenopus tadpole spinal cord and hindbrain, which generate swimming rhythms. Silencing activity on one side led to rapid cessation of activity on the other side. Analyses reveal that this resulted from the depression of reciprocal inhibition connecting the two sides. Although critical neurons in intact tadpoles are capable of pacemaker firing individually, an effect that could support motor rhythms without inhibition, the swimming network itself requires ∼23 min to regain rhythmic activity after blocking inhibition pharmacologically, implying some homeostatic changes. We conclude therefore that reciprocal inhibition is critical for the generation of normal locomotor rhythm. 2013-01-09T00:00:00Z Moult, Peter Robert Cottrell, Glen Alfred Li, Wenchang Summary Alternating contractions of antagonistic muscle groups during locomotion are generated by spinal “half-center” networks coupled in antiphase by reciprocal inhibition. It is widely thought that reciprocal inhibition only coordinates the activity of these muscles. We have devised two methods to rapidly and selectively silence neurons on just one side of Xenopus tadpole spinal cord and hindbrain, which generate swimming rhythms. Silencing activity on one side led to rapid cessation of activity on the other side. Analyses reveal that this resulted from the depression of reciprocal inhibition connecting the two sides. Although critical neurons in intact tadpoles are capable of pacemaker firing individually, an effect that could support motor rhythms without inhibition, the swimming network itself requires ∼23 min to regain rhythmic activity after blocking inhibition pharmacologically, implying some homeostatic changes. We conclude therefore that reciprocal inhibition is critical for the generation of normal locomotor rhythm. http://hdl.handle.net/10023/3326 Abstract: Adult nervous systems are so complex that understanding how they produce behavior remains a real challenge. We chose to study hatchling Xenopus tadpoles where behavior is controlled by a few thousand neurons but there is a very limited number of types of neuron. Young tadpoles can flex, swim away, adjust their trajectory, speed-up and slow-down, stop when they contact support and struggle when grasped. They are sensitive to touch, pressure, noxious stimuli, light intensity and water currents. Using whole-cell recording has led to rapid progress in understanding central networks controlling behavior. Our methods are illustrated by an analysis of the flexion reflex to skin touch. We then define the seven types of neuron that allow the tadpole to swim when the skin is touched and use paired recordings to investigate neuron properties, synaptic connections and activity patterns. Proposals on how the swim network operates are evaluated by experiment and network modeling. We then examine GABAergic inhibitory pathways that control swimming but also produce tonic inhibition to reduce responsiveness when the tadpole is at rest. Finally, we analyze the strong alternating struggling movements the tadpole makes when grasped. We show that the mechanisms for rhythm generation here are very different to those during swimming. Although much remains to be explained, study of this simple vertebrate has uncovered basic principles about the function and organization of vertebrate nervous systems. 2010-06-24T00:00:00Z Roberts, Alan Li, Wen-Chang Soffe, Steve Adult nervous systems are so complex that understanding how they produce behavior remains a real challenge. We chose to study hatchling Xenopus tadpoles where behavior is controlled by a few thousand neurons but there is a very limited number of types of neuron. Young tadpoles can flex, swim away, adjust their trajectory, speed-up and slow-down, stop when they contact support and struggle when grasped. They are sensitive to touch, pressure, noxious stimuli, light intensity and water currents. Using whole-cell recording has led to rapid progress in understanding central networks controlling behavior. Our methods are illustrated by an analysis of the flexion reflex to skin touch. We then define the seven types of neuron that allow the tadpole to swim when the skin is touched and use paired recordings to investigate neuron properties, synaptic connections and activity patterns. Proposals on how the swim network operates are evaluated by experiment and network modeling. We then examine GABAergic inhibitory pathways that control swimming but also produce tonic inhibition to reduce responsiveness when the tadpole is at rest. Finally, we analyze the strong alternating struggling movements the tadpole makes when grasped. We show that the mechanisms for rhythm generation here are very different to those during swimming. Although much remains to be explained, study of this simple vertebrate has uncovered basic principles about the function and organization of vertebrate nervous systems. http://hdl.handle.net/10023/3325 Abstract: Spatial memory is a well-characterized psychological function in both humans and rodents. The combined computations of a network of systems including place cells in the hippocampus, grid cells in the medial entorhinal cortex and head direction cells found in numerous structures in the brain have been suggested to form the neural instantiation of the cognitive map as first described by Tolman in 1948. However, while our understanding of the neural mechanisms underlying spatial representations in adults is relatively sophisticated, we know substantially less about how this network develops in young animals. In this article we briefly review studies examining the developmental time scale that these systems follow. Electrophysiological recordings from very young rats show that directional information is at adult levels at the outset of navigational experience. The systems supporting allocentric memory, however, take longer to mature. This is consistent with behavioral studies of young rats which show that spatial memory based on head direction develops very early but that allocentric spatial memory takes longer to mature. We go on to report new data demonstrating that memory for associations between objects and their spatial locations is slower to develop than memory for objects alone. This is again consistent with previous reports suggesting that adult like spatial representations have a protracted development in rats and also suggests that the systems involved in processing non-spatial stimuli come online earlier. 2012-03-01T00:00:00Z Ainge, James A. Langston, Rosamund F. Spatial memory is a well-characterized psychological function in both humans and rodents. The combined computations of a network of systems including place cells in the hippocampus, grid cells in the medial entorhinal cortex and head direction cells found in numerous structures in the brain have been suggested to form the neural instantiation of the cognitive map as first described by Tolman in 1948. However, while our understanding of the neural mechanisms underlying spatial representations in adults is relatively sophisticated, we know substantially less about how this network develops in young animals. In this article we briefly review studies examining the developmental time scale that these systems follow. Electrophysiological recordings from very young rats show that directional information is at adult levels at the outset of navigational experience. The systems supporting allocentric memory, however, take longer to mature. This is consistent with behavioral studies of young rats which show that spatial memory based on head direction develops very early but that allocentric spatial memory takes longer to mature. We go on to report new data demonstrating that memory for associations between objects and their spatial locations is slower to develop than memory for objects alone. This is again consistent with previous reports suggesting that adult like spatial representations have a protracted development in rats and also suggests that the systems involved in processing non-spatial stimuli come online earlier. http://hdl.handle.net/10023/3323 Abstract: Our forward-facing eyes allow us the advantage of binocular visual information: using the tiny differences between right and left eye views to learn about depth and location in three dimensions. Our visual systems also contain specialized mechanisms to detect motion-in-depth from binocular vision, but the nature of these mechanisms remains controversial. Binocular motion-in-depth perception could theoretically be based on first detecting binocular disparity and then monitoring how it changes over time. The alternative is to monitor the motion in the right and left eye separately and then compare these motion signals. Here we used an individual differences approach to test whether the two sources of information are processed via dissociated mechanisms, and to measure the relative importance of those mechanisms. Our results suggest the existence of two distinct mechanisms, each contributing to the perception of motion-in-depth in most observers. Additionally, for the first time, we demonstrate the relative prevalence of the two mechanisms within a normal population. In general, visual systems appear to rely mostly on the mechanism sensitive to changing binocular disparity, but perception of motion-in-depth is augmented by the presence of a less sensitive mechanism that uses interocular velocity differences. Occasionally, we find observers with the opposite pattern of sensitivity. More generally this work showcases the power of the individual differences approach in studying the functional organization of cognitive systems. 2010-10-12T00:00:00Z Nefs, Harold O'Hare, Louise Harris, Julie Our forward-facing eyes allow us the advantage of binocular visual information: using the tiny differences between right and left eye views to learn about depth and location in three dimensions. Our visual systems also contain specialized mechanisms to detect motion-in-depth from binocular vision, but the nature of these mechanisms remains controversial. Binocular motion-in-depth perception could theoretically be based on first detecting binocular disparity and then monitoring how it changes over time. The alternative is to monitor the motion in the right and left eye separately and then compare these motion signals. Here we used an individual differences approach to test whether the two sources of information are processed via dissociated mechanisms, and to measure the relative importance of those mechanisms. Our results suggest the existence of two distinct mechanisms, each contributing to the perception of motion-in-depth in most observers. Additionally, for the first time, we demonstrate the relative prevalence of the two mechanisms within a normal population. In general, visual systems appear to rely mostly on the mechanism sensitive to changing binocular disparity, but perception of motion-in-depth is augmented by the presence of a less sensitive mechanism that uses interocular velocity differences. Occasionally, we find observers with the opposite pattern of sensitivity. More generally this work showcases the power of the individual differences approach in studying the functional organization of cognitive systems. http://hdl.handle.net/10023/3271 Abstract: Little is known about mate choice preferences outside Western, educated, industrialised, rich and democratic societies, even though these Western populations may be particularly unrepresentative of human populations. To our knowledge, this is the first study to test which facial cues contribute to African perceptions of African female attractiveness and also the first study to test the combined role of facial adiposity, skin colour (lightness, yellowness and redness), skin homogeneity and youthfulness in the facial attractiveness preferences of any population. Results show that youthfulness, skin colour, skin homogeneity and facial adiposity significantly and independently predict attractiveness in female African faces. Younger, thinner women with a lighter, yellower skin colour and a more homogenous skin tone are considered more attractive. These findings provide a more global perspective on human mate choice and point to a universal role for these four facial cues in female facial attractiveness. 2012-10-29T00:00:00Z Coetzee, Vinet Faerber, Stella J Greeff, Jaco M Lefevre, Carmen Emilia Re, Daniel Perrett, David Ian Little is known about mate choice preferences outside Western, educated, industrialised, rich and democratic societies, even though these Western populations may be particularly unrepresentative of human populations. To our knowledge, this is the first study to test which facial cues contribute to African perceptions of African female attractiveness and also the first study to test the combined role of facial adiposity, skin colour (lightness, yellowness and redness), skin homogeneity and youthfulness in the facial attractiveness preferences of any population. Results show that youthfulness, skin colour, skin homogeneity and facial adiposity significantly and independently predict attractiveness in female African faces. Younger, thinner women with a lighter, yellower skin colour and a more homogenous skin tone are considered more attractive. These findings provide a more global perspective on human mate choice and point to a universal role for these four facial cues in female facial attractiveness. http://hdl.handle.net/10023/3268 Abstract: Blood oxygenation level is associated with cardiovascular fitness, and raising oxygenated blood colouration in human faces increases perceived health. The current study used a two-alternative forced choice (2AFC) psychophysics design to quantify the oxygenated blood colour (redness) change threshold required to affect perception of facial colour, health and attractiveness. Detection thresholds for colour judgments were lower than those for health and attractiveness, which did not differ. The results suggest redness preferences do not reflect a sensory bias, rather preferences may be based on accurate indications of health status. Furthermore, results suggest perceived health and attractiveness may be perceptually equivalent when they are assessed based on facial redness. Appearance-based motivation for lifestyle change can be effective; thus future studies could assess the degree to which cardiovascular fitness increases face redness and could quantify changes in aerobic exercise needed to increase facial attractiveness. 2011-03-23T00:00:00Z Re, Daniel E. Whitehead, Ross D. Xiao, Dengke Perrett, David I. Blood oxygenation level is associated with cardiovascular fitness, and raising oxygenated blood colouration in human faces increases perceived health. The current study used a two-alternative forced choice (2AFC) psychophysics design to quantify the oxygenated blood colour (redness) change threshold required to affect perception of facial colour, health and attractiveness. Detection thresholds for colour judgments were lower than those for health and attractiveness, which did not differ. The results suggest redness preferences do not reflect a sensory bias, rather preferences may be based on accurate indications of health status. Furthermore, results suggest perceived health and attractiveness may be perceptually equivalent when they are assessed based on facial redness. Appearance-based motivation for lifestyle change can be effective; thus future studies could assess the degree to which cardiovascular fitness increases face redness and could quantify changes in aerobic exercise needed to increase facial attractiveness. http://hdl.handle.net/10023/3266 Abstract: In a range of non-human primate, bird and fish species, the intensity of red coloration in males is associated with social dominance, testosterone levels and mate selection. In humans too, skin redness is associated with health, but it is not known whether - as in non-human species - it is also associated with dominance and links to attractiveness have not been thoroughly investigated. Here we allow female participants to manipulate the CIELab a* value (red-green axis) of skin to maximize the perceived aggression, dominance and attractiveness of photographs of men's faces, and make two findings. First, participants increased a* (increasing redness) to enhance each attribute, suggesting that facial redness is perceived as conveying similar information about a male's qualities in humans as it does in non-human species. Second, there were significant differences between trial types: the highest levels of red were associated with aggression, an intermediate level with dominance, and the least with attractiveness. These differences may reflect a trade-off between the benefits of selecting a healthy, dominant partner and the negative consequences of aggression. 2012-01-01T00:00:00Z Stephen, Ian D. Oldham, Francesca H. Perrett, David I. Barton, Robert A. In a range of non-human primate, bird and fish species, the intensity of red coloration in males is associated with social dominance, testosterone levels and mate selection. In humans too, skin redness is associated with health, but it is not known whether - as in non-human species - it is also associated with dominance and links to attractiveness have not been thoroughly investigated. Here we allow female participants to manipulate the CIELab a* value (red-green axis) of skin to maximize the perceived aggression, dominance and attractiveness of photographs of men's faces, and make two findings. First, participants increased a* (increasing redness) to enhance each attribute, suggesting that facial redness is perceived as conveying similar information about a male's qualities in humans as it does in non-human species. Second, there were significant differences between trial types: the highest levels of red were associated with aggression, an intermediate level with dominance, and the least with attractiveness. These differences may reflect a trade-off between the benefits of selecting a healthy, dominant partner and the negative consequences of aggression. http://hdl.handle.net/10023/3265 Abstract: How does participation in a long-duration mass gathering (such as a pilgrimage event) impact well-being? There are good reasons to believe such collective events pose risks to health. There are risks associated with communicable diseases. Moreover, the physical conditions at such events (noise, crowding, harsh conditions) are often detrimental to well-being. Yet, at the same time, social psychological research suggests participation in group-related activities can impact well-being positively, and we therefore investigated if participating in a long-duration mass gathering can actually bring such benefits. In our research we studied one of the world's largest collective events – a demanding month-long Hindu religious festival in North India. Participants (comprising 416 pilgrims who attended the gathering for the whole month of its duration, and 127 controls who did not) completed measures of self-assessed well-being and symptoms of ill-health at two time points. The first was a month before the gathering commenced, the second was a month after it finished. We found that those participating in this collective event reported a longitudinal increase in well-being relative to those who did not participate. Our data therefore imply we should reconceptualise how mass gatherings impact individuals. Although such gatherings can entail significant health risks, the benefits for well-being also need recognition. Indeed, an exclusive focus on risk is misleading and limits our understanding of why such events may be so attractive. More importantly, as our research is longitudinal and includes a control group, our work adds robust evidence to the social psychological literature concerning the relationship between participation in social group activities and well-being. 2012-10-17T00:00:00Z Tewari, Shruti Khan, Sammyh Hopkins, Nick Srinivasan, Narayanan Reicher, Stephen David How does participation in a long-duration mass gathering (such as a pilgrimage event) impact well-being? There are good reasons to believe such collective events pose risks to health. There are risks associated with communicable diseases. Moreover, the physical conditions at such events (noise, crowding, harsh conditions) are often detrimental to well-being. Yet, at the same time, social psychological research suggests participation in group-related activities can impact well-being positively, and we therefore investigated if participating in a long-duration mass gathering can actually bring such benefits. In our research we studied one of the world's largest collective events – a demanding month-long Hindu religious festival in North India. Participants (comprising 416 pilgrims who attended the gathering for the whole month of its duration, and 127 controls who did not) completed measures of self-assessed well-being and symptoms of ill-health at two time points. The first was a month before the gathering commenced, the second was a month after it finished. We found that those participating in this collective event reported a longitudinal increase in well-being relative to those who did not participate. Our data therefore imply we should reconceptualise how mass gatherings impact individuals. Although such gatherings can entail significant health risks, the benefits for well-being also need recognition. Indeed, an exclusive focus on risk is misleading and limits our understanding of why such events may be so attractive. More importantly, as our research is longitudinal and includes a control group, our work adds robust evidence to the social psychological literature concerning the relationship between participation in social group activities and well-being. http://hdl.handle.net/10023/3264 Abstract: Understanding of the psychology of tyranny is dominated by classic studies from the 1960s and 1970s: Milgram's research on obedience to authority and Zimbardo's Stanford Prison Experiment. Supporting popular notions of the banality of evil, this research has been taken to show that people conform passively and unthinkingly to both the instructions and the roles that authorities provide, however malevolent these may be. Recently, though, this consensus has been challenged by empirical work informed by social identity theorizing. This suggests that individuals' willingness to follow authorities is conditional on identification with the authority in question and an associated belief that the authority is right. 2012-11-20T00:00:00Z Haslam, Alexander Reicher, Stephen David Understanding of the psychology of tyranny is dominated by classic studies from the 1960s and 1970s: Milgram's research on obedience to authority and Zimbardo's Stanford Prison Experiment. Supporting popular notions of the banality of evil, this research has been taken to show that people conform passively and unthinkingly to both the instructions and the roles that authorities provide, however malevolent these may be. Recently, though, this consensus has been challenged by empirical work informed by social identity theorizing. This suggests that individuals' willingness to follow authorities is conditional on identification with the authority in question and an associated belief that the authority is right. http://hdl.handle.net/10023/3254 Abstract: Background: People over the age of 70 carry the greatest burden of chronic disease, disability and health care use. Participation in physical activity is crucial for health, and walking accounts for much of the physical activity undertaken by sedentary individuals. Pedometers are a useful motivational tool to encourage increased walking and they are cheap and easy to use. The aim of this pilot study was to evaluate the feasibility of the use of pedometers plus a theory-based intervention to assist sedentary older women to accumulate increasing amounts of physical activity, mainly through walking. Methods: Female participants over the age of 70 were recruited from primary care and randomised to receive either pedometer plus a theory-based intervention or a theory-based intervention alone. The theory-based intervention consisted of motivational techniques, goal-setting, barrier identification and self-monitoring with pedometers and daily diaries. The pedometer group were further randomised to one of three target groups: a 10%, 15% or 20% monthly increase in step count to assess the achievability and acceptability of a range of targets. The primary outcome was change in daily activity levels measured by accelerometry. Secondary outcome measures were lower limb function, health related quality of life, anxiety and depression. Results: 54 participants were recruited into the study, with an average age of 76. There were 9 drop outs, 45 completing the study. All participants in the pedometer group found the pedometers easy to use and there was good compliance with diary keeping (96% in the pedometer group and 83% in the theory-based intervention alone group). There was a strong correlation (0.78) between accelerometry and pedometer step counts i.e. indicating that walking was the main physical activity amongst participants. There was a greater increase in activity (accelerometry) amongst those in the 20% target pedometer group compared to the other groups, although not reaching statistical significance (p = 0.192). Conclusion: We have demonstrated that it is feasible to use pedometers and provide theory-based advice to community dwelling sedentary older women to increase physical activity levels and a larger study is planned to investigate this further. 2008-08-08T00:00:00Z Sugden, Jacqui A. Sniehotta, Falko F. Donnan, Peter T. Boyle, Paul Johnston, Derek W. McMurdo, Marion E. T. Background: People over the age of 70 carry the greatest burden of chronic disease, disability and health care use. Participation in physical activity is crucial for health, and walking accounts for much of the physical activity undertaken by sedentary individuals. Pedometers are a useful motivational tool to encourage increased walking and they are cheap and easy to use. The aim of this pilot study was to evaluate the feasibility of the use of pedometers plus a theory-based intervention to assist sedentary older women to accumulate increasing amounts of physical activity, mainly through walking. Methods: Female participants over the age of 70 were recruited from primary care and randomised to receive either pedometer plus a theory-based intervention or a theory-based intervention alone. The theory-based intervention consisted of motivational techniques, goal-setting, barrier identification and self-monitoring with pedometers and daily diaries. The pedometer group were further randomised to one of three target groups: a 10%, 15% or 20% monthly increase in step count to assess the achievability and acceptability of a range of targets. The primary outcome was change in daily activity levels measured by accelerometry. Secondary outcome measures were lower limb function, health related quality of life, anxiety and depression. Results: 54 participants were recruited into the study, with an average age of 76. There were 9 drop outs, 45 completing the study. All participants in the pedometer group found the pedometers easy to use and there was good compliance with diary keeping (96% in the pedometer group and 83% in the theory-based intervention alone group). There was a strong correlation (0.78) between accelerometry and pedometer step counts i.e. indicating that walking was the main physical activity amongst participants. There was a greater increase in activity (accelerometry) amongst those in the 20% target pedometer group compared to the other groups, although not reaching statistical significance (p = 0.192). Conclusion: We have demonstrated that it is feasible to use pedometers and provide theory-based advice to community dwelling sedentary older women to increase physical activity levels and a larger study is planned to investigate this further. http://hdl.handle.net/10023/3245 Abstract: Theories of schizophrenia propose that abnormal functioning of the neural reward system is linked to negative and psychotic symptoms, by disruption of reward processing and promotion of context-independent false associations. Recently it has been argued that an insula-anterior cingulate cortex (ACC) salience network system enables switching of brain states from the default mode to a task-related activity mode. Abnormal interaction between the insula-ACC system and reward processing regions may help explain abnormal reinforcer processing and symptoms. Here we use fMRI to assess the neural correlates of reward processing in schizophrenia. Furthermore we investigated functional connectivity between the dopaminergic midbrain, a key region for the processing of reinforcers, and other brain regions. In response to rewards, controls activated task related regions (striatum, amygdala/hippocampus and midbrain) and the insula-ACC salience network. Patients similarly activated the insula-ACC salience network system but failed to activate task related regions. Reduced functional connectivity between the midbrain and the insula was found in schizophrenia, with the extent of this abnormality correlating with increased psychotic symptoms. The findings support the notion that reward processing is abnormal in schizophrenia and highlight the potential role of abnormal interactions between the insula-ACC salience network and reward regions. 2013-02-28T00:00:00Z Gradin, Victoria Waiter, Gordon O'Connor, Akira Robert Romaniuk, Liana Stickle, Catriona Matthews, Keith Hall, Jeremy Steele, Douglas Theories of schizophrenia propose that abnormal functioning of the neural reward system is linked to negative and psychotic symptoms, by disruption of reward processing and promotion of context-independent false associations. Recently it has been argued that an insula-anterior cingulate cortex (ACC) salience network system enables switching of brain states from the default mode to a task-related activity mode. Abnormal interaction between the insula-ACC system and reward processing regions may help explain abnormal reinforcer processing and symptoms. Here we use fMRI to assess the neural correlates of reward processing in schizophrenia. Furthermore we investigated functional connectivity between the dopaminergic midbrain, a key region for the processing of reinforcers, and other brain regions. In response to rewards, controls activated task related regions (striatum, amygdala/hippocampus and midbrain) and the insula-ACC salience network. Patients similarly activated the insula-ACC salience network system but failed to activate task related regions. Reduced functional connectivity between the midbrain and the insula was found in schizophrenia, with the extent of this abnormality correlating with increased psychotic symptoms. The findings support the notion that reward processing is abnormal in schizophrenia and highlight the potential role of abnormal interactions between the insula-ACC salience network and reward regions. http://hdl.handle.net/10023/3243 Abstract: Cortical regions supporting cognitive control and memory judgment are structurally immature in adolescents. Here we studied adolescents (13-15 y.o.) and young adults (20-22 y.o.) using a recognition memory paradigm that modulates cognitive control demands through cues that probabilistically forecast memory probe status. Behaviorally, adolescence was associated with quicker responding in the presence of invalid cues compared to young adulthood. FMRI data demonstrated that while both groups increasingly activated posterior dorsolateral prefrontal (dlPFC), midline, and lateral parietal regions for invalidly compared to validly cued trials, this differential invalid cueing response ended sooner in adolescents, consistent with their generally quicker responding on cued trials. Critically, dlPFC also demonstrated reversed brain-behavior associations across the groups. Increased mean dlPFC activation during invalid cueing was linked to improved performance in young adults, whereas increases within adolescents were linked to impaired performance. Resting state connectivity analysis revealed greater connectivity between dlPFC and episodic retrieval linked regions in young adults relative to adolescents. These data demonstrate that the functional interpretation of dlPFC activation hinges on its physical maturation and suggest that the pattern of behavioral and neural response in adolescents reflects different functional integration of cognitive control and memory systems. 2012-12-01T00:00:00Z Jaeger, Antonio Selmeczy, Diana O'Connor, Akira Robert Diaz, Michael Dobbins, Ian Cortical regions supporting cognitive control and memory judgment are structurally immature in adolescents. Here we studied adolescents (13-15 y.o.) and young adults (20-22 y.o.) using a recognition memory paradigm that modulates cognitive control demands through cues that probabilistically forecast memory probe status. Behaviorally, adolescence was associated with quicker responding in the presence of invalid cues compared to young adulthood. FMRI data demonstrated that while both groups increasingly activated posterior dorsolateral prefrontal (dlPFC), midline, and lateral parietal regions for invalidly compared to validly cued trials, this differential invalid cueing response ended sooner in adolescents, consistent with their generally quicker responding on cued trials. Critically, dlPFC also demonstrated reversed brain-behavior associations across the groups. Increased mean dlPFC activation during invalid cueing was linked to improved performance in young adults, whereas increases within adolescents were linked to impaired performance. Resting state connectivity analysis revealed greater connectivity between dlPFC and episodic retrieval linked regions in young adults relative to adolescents. These data demonstrate that the functional interpretation of dlPFC activation hinges on its physical maturation and suggest that the pattern of behavioral and neural response in adolescents reflects different functional integration of cognitive control and memory systems. http://hdl.handle.net/10023/3227 Abstract: The degree to which non-human primate behaviour is lateralized, at individual or population levels, remains controversial and over the last century, the issue of brain lateralization in primates has been extensively researched and debated, yet no previous study has reported eye preference or head turning in great apes. This thesis examines three different expressions of hemispheric asymmetry in lateralized behaviours: hand preference for bipedal tool use, eye preference, and auditory laterality. It is reported that bipedalism induced the subjects to become more lateralized, but not in any particular direction. Instead, it appeared that subtle pre-existing lateral biases, to the right or left, were emphasized with increasing postural demands. Eye preference was assessed when animals looked through a hole, using one eye, at an empty box, a mirror, a picture of a dog, a rubber snake, food biscuits, bananas, a rubber duck and a video camera. Main effects of stimulus type were reported for direction of eye preference, number of looks, and looking duration, but not for strength of eye preference. A left-eye bias was found for viewing the rubber snake and a right eye bias was found for viewing the bananas. In addition, a significant shift in eye preference took place from the initial look to subsequent looks when viewing the snake. The results reported are not consistent with the literature for other primate studies. Lastly, auditory laterality was assessed using the Hauser and Andersson (1994) head turning paradigm. Chimpanzee and American crow calls were broadcast to subjects from 180° behind them and directional head turning was recorded. No difference in turning direction or latency was found. This lack of result was attributed to the methodology and underlying assumption that head turning is directly related to hemispheric asymmetries and not influenced by any other processes. 2012-11-30T00:00:00Z Braccini, Stephanie The degree to which non-human primate behaviour is lateralized, at individual or population levels, remains controversial and over the last century, the issue of brain lateralization in primates has been extensively researched and debated, yet no previous study has reported eye preference or head turning in great apes. This thesis examines three different expressions of hemispheric asymmetry in lateralized behaviours: hand preference for bipedal tool use, eye preference, and auditory laterality. It is reported that bipedalism induced the subjects to become more lateralized, but not in any particular direction. Instead, it appeared that subtle pre-existing lateral biases, to the right or left, were emphasized with increasing postural demands. Eye preference was assessed when animals looked through a hole, using one eye, at an empty box, a mirror, a picture of a dog, a rubber snake, food biscuits, bananas, a rubber duck and a video camera. Main effects of stimulus type were reported for direction of eye preference, number of looks, and looking duration, but not for strength of eye preference. A left-eye bias was found for viewing the rubber snake and a right eye bias was found for viewing the bananas. In addition, a significant shift in eye preference took place from the initial look to subsequent looks when viewing the snake. The results reported are not consistent with the literature for other primate studies. Lastly, auditory laterality was assessed using the Hauser and Andersson (1994) head turning paradigm. Chimpanzee and American crow calls were broadcast to subjects from 180° behind them and directional head turning was recorded. No difference in turning direction or latency was found. This lack of result was attributed to the methodology and underlying assumption that head turning is directly related to hemispheric asymmetries and not influenced by any other processes. http://hdl.handle.net/10023/3223 Abstract: The findings of two recent studies suggest that cuteness sensitivity may be modulated by the female reproductive hormones estrogen and progesterone, with women showing greater sensitivity than men (Sprengelmeyer et al 2009; Lobmaier et al 2010) and women using hormonal contraceptives showing a greater sensitivity than naturally cycling women. Post-menopausal women were found to perform at the same level as men (Sprengelmeyer et al 2009). The present study aimed to extend these findings by determining if an equivalent pattern of differences occurs in the motivation to view pictures of infant faces. To investigate this question, men, naturally cycling women and women using oral contraceptives completed a key-press task in which they were able to increase or decrease the amount of time they spent viewing infant faces that varied in gender, expression and age. Following this, they rated the same set of faces for cuteness. Because levels of estrogen and progesterone fluctuate over the course of the menstrual cycle and over a month of oral contraceptive use, naturally cycling women and women using oral contraceptives completed the experiment at different times of their menstrual cycle or oral contraceptive regimen to determine the effects of cycle phase (menstrual, late follicular, luteal) and pill stage (pill phase, pill-break) on the level of key-pressing. Three key findings were made. First, there is no gender difference in the cuteness judgments of infant faces suggesting that cuteness is a universal construct, perceived in the same way by all. Second, there is a strong correlation between cuteness rating and viewing time, providing evidence that the incentive value of an infant face is modulated by cuteness. And third, there is no evidence that the incentive value of cuteness is hormonally modulated. Regardless of gender, pill phase or cycle phase, the participants showed no difference in their motivation to view the infant faces. From these findings it appears that whilst sensitivity to cuteness in infant faces may be modulated by estrogen and progesterone, the motivation to view cute infant faces is not. It was concluded that these different components of cuteness processing evolved separately for different purposes associated with infant care. 2012-11-30T00:00:00Z Lewis, Jennifer The findings of two recent studies suggest that cuteness sensitivity may be modulated by the female reproductive hormones estrogen and progesterone, with women showing greater sensitivity than men (Sprengelmeyer et al 2009; Lobmaier et al 2010) and women using hormonal contraceptives showing a greater sensitivity than naturally cycling women. Post-menopausal women were found to perform at the same level as men (Sprengelmeyer et al 2009). The present study aimed to extend these findings by determining if an equivalent pattern of differences occurs in the motivation to view pictures of infant faces. To investigate this question, men, naturally cycling women and women using oral contraceptives completed a key-press task in which they were able to increase or decrease the amount of time they spent viewing infant faces that varied in gender, expression and age. Following this, they rated the same set of faces for cuteness. Because levels of estrogen and progesterone fluctuate over the course of the menstrual cycle and over a month of oral contraceptive use, naturally cycling women and women using oral contraceptives completed the experiment at different times of their menstrual cycle or oral contraceptive regimen to determine the effects of cycle phase (menstrual, late follicular, luteal) and pill stage (pill phase, pill-break) on the level of key-pressing. Three key findings were made. First, there is no gender difference in the cuteness judgments of infant faces suggesting that cuteness is a universal construct, perceived in the same way by all. Second, there is a strong correlation between cuteness rating and viewing time, providing evidence that the incentive value of an infant face is modulated by cuteness. And third, there is no evidence that the incentive value of cuteness is hormonally modulated. Regardless of gender, pill phase or cycle phase, the participants showed no difference in their motivation to view the infant faces. From these findings it appears that whilst sensitivity to cuteness in infant faces may be modulated by estrogen and progesterone, the motivation to view cute infant faces is not. It was concluded that these different components of cuteness processing evolved separately for different purposes associated with infant care. http://hdl.handle.net/10023/3209 Abstract: The present study was aimed at investigating a potential mechanism behind retrieval-induced forgetting that we have termed resource allocation. Three experiments were designed around the notion that increasing the number memories associated with one concept may reduce retrieval-induced forgetting by spreading out the limited resources available for that concept. In two experiments, we expanded the standard retrieval-induced forgetting (RIF) paradigm by increasing the number of items in each category and varying the amount of Rp+ and Rp- items. In one of these experiments, we recorded event-related potentials (ERPs) to examine the electrophysiological correlates of retrieval-induced forgetting. We then compared these findings to a standard version of the RIF paradigm as a control experiment. All three experiments produced significant facilitation effects, but failed to produce retrieval-induced forgetting. The absence of RIF in the present study, however, when combined with the imaging data allows us to discern the ERP correlates of selective retrieval from those of retrieval-induced forgetting. In the discussion, we present our case against conclusions drawn in other studies about the ERP correlates of RIF, and suggest that the characteristic frontoparietal components often found in RIF studies reflect the neural correlates of selective retrieval rather than inhibition. 2012-06-19T00:00:00Z Walters, Marie The present study was aimed at investigating a potential mechanism behind retrieval-induced forgetting that we have termed resource allocation. Three experiments were designed around the notion that increasing the number memories associated with one concept may reduce retrieval-induced forgetting by spreading out the limited resources available for that concept. In two experiments, we expanded the standard retrieval-induced forgetting (RIF) paradigm by increasing the number of items in each category and varying the amount of Rp+ and Rp- items. In one of these experiments, we recorded event-related potentials (ERPs) to examine the electrophysiological correlates of retrieval-induced forgetting. We then compared these findings to a standard version of the RIF paradigm as a control experiment. All three experiments produced significant facilitation effects, but failed to produce retrieval-induced forgetting. The absence of RIF in the present study, however, when combined with the imaging data allows us to discern the ERP correlates of selective retrieval from those of retrieval-induced forgetting. In the discussion, we present our case against conclusions drawn in other studies about the ERP correlates of RIF, and suggest that the characteristic frontoparietal components often found in RIF studies reflect the neural correlates of selective retrieval rather than inhibition. http://hdl.handle.net/10023/3186 Abstract: Animal social learning has become a subject of broad interest, but demonstrations of bodily imitation in animals remain rare. Based on Voelkl and Huber's study of imitation by marmosets, we tested four groups of semi-captive vervet monkeys presented with food in modified film canisters (“aethipops’). One individual was trained to take the tops off canisters in each group and demonstrated five openings to them. In three groups these models used their mouth to remove the lid, but in one of the groups the model also spontaneously pulled ropes on a canister to open it. In the last group the model preferred to remove the lid with her hands. Following these spontaneous differentiations of foraging techniques in the models, we observed the techniques used by the other group members to open the canisters. We found that mouth opening was the most common technique overall, but the rope and hands methods were used significantly more in groups they were demonstrated in than in groups where they were not. Our results show bodily matching that is conventionally described as imitation. We discuss the relevance of these findings to discoveries about mirror neurons, and implications of the identity of the model for social transmission. 2012-10-10T00:00:00Z van de Waal, Erica Whiten, Andrew Animal social learning has become a subject of broad interest, but demonstrations of bodily imitation in animals remain rare. Based on Voelkl and Huber's study of imitation by marmosets, we tested four groups of semi-captive vervet monkeys presented with food in modified film canisters (“aethipops’). One individual was trained to take the tops off canisters in each group and demonstrated five openings to them. In three groups these models used their mouth to remove the lid, but in one of the groups the model also spontaneously pulled ropes on a canister to open it. In the last group the model preferred to remove the lid with her hands. Following these spontaneous differentiations of foraging techniques in the models, we observed the techniques used by the other group members to open the canisters. We found that mouth opening was the most common technique overall, but the rope and hands methods were used significantly more in groups they were demonstrated in than in groups where they were not. Our results show bodily matching that is conventionally described as imitation. We discuss the relevance of these findings to discoveries about mirror neurons, and implications of the identity of the model for social transmission. http://hdl.handle.net/10023/3183 Abstract: Located in the mesopontine tegmentum, the pedunculopontine tegmental nucleus (PPTg) is comprised principally of glutamatergic, cholinergic and GABAergic neurons. In addition to being fully integrated into basal ganglia, PPTg projects to thalamus and motor output sites in the brainstem. Previous studies have shown a range of behavioural changes after PPTg manipulation. Prominent amongst these is an apparent deficit in the ability to learn the consequences of actions. PPTg is divisible into a posterior component (pPPTg) in receipt of rapid polymodal sensory input and projecting into VTA/SNc dopamine neurons and an anterior component (aPPTg) in receipt of basal ganglia outflow and projecting into SNc and lower brainstem structures. The research described here assesses the role of the pPPTg in instrumental learning. Using a contingency degradation paradigm, it was shown that inactivation of the pPPTg (by muscimol microinfusion) specifically blocked the updating of associations between actions and outcomes, without the affecting the ability to re-execute previously learned instrumental actions. Selective bilateral destruction of pPPTg cholinergic neurons (with the fusion toxin diphtheria toxin – urotensin II [Dtx-UII]) resulted in >90% loss of pPPTg cholinergic neurons. These lesions produced no detectable changes on any measured aspect of an instrumental learning task consisting of various fixed and variable ratio schedules of reinforcement and extinction. Subsequent experiments found that the same selective cholinergic pPPTg lesions also produced no changes in the locomotor response to nicotine or rate of nicotine sensitisation. These results are the first to demonstrate a brainstem role in action-outcome learning. Results support the view that PPTg performs a ‘first pass’ analysis on incoming sensory data and interfaces salient aspects of this with appropriate basal ganglia and brainstem circuitry, with glutamatergic pPPTg projections sending an essential signal and cholinergic projections performing as part of a wider modulatory system. 2012-11-01T00:00:00Z MacLaren, Duncan A.A. Located in the mesopontine tegmentum, the pedunculopontine tegmental nucleus (PPTg) is comprised principally of glutamatergic, cholinergic and GABAergic neurons. In addition to being fully integrated into basal ganglia, PPTg projects to thalamus and motor output sites in the brainstem. Previous studies have shown a range of behavioural changes after PPTg manipulation. Prominent amongst these is an apparent deficit in the ability to learn the consequences of actions. PPTg is divisible into a posterior component (pPPTg) in receipt of rapid polymodal sensory input and projecting into VTA/SNc dopamine neurons and an anterior component (aPPTg) in receipt of basal ganglia outflow and projecting into SNc and lower brainstem structures. The research described here assesses the role of the pPPTg in instrumental learning. Using a contingency degradation paradigm, it was shown that inactivation of the pPPTg (by muscimol microinfusion) specifically blocked the updating of associations between actions and outcomes, without the affecting the ability to re-execute previously learned instrumental actions. Selective bilateral destruction of pPPTg cholinergic neurons (with the fusion toxin diphtheria toxin – urotensin II [Dtx-UII]) resulted in >90% loss of pPPTg cholinergic neurons. These lesions produced no detectable changes on any measured aspect of an instrumental learning task consisting of various fixed and variable ratio schedules of reinforcement and extinction. Subsequent experiments found that the same selective cholinergic pPPTg lesions also produced no changes in the locomotor response to nicotine or rate of nicotine sensitisation. These results are the first to demonstrate a brainstem role in action-outcome learning. Results support the view that PPTg performs a ‘first pass’ analysis on incoming sensory data and interfaces salient aspects of this with appropriate basal ganglia and brainstem circuitry, with glutamatergic pPPTg projections sending an essential signal and cholinergic projections performing as part of a wider modulatory system. http://hdl.handle.net/10023/3152 Abstract: Anxiety disorders commonly emerge during adolescence, and girls are diagnosed with these disorders more frequently than boys. Understanding why anxiety disorders emerge and why non-clinical anxiety symptoms increase during adolescence is important for understanding this sex difference and how to treat adolescent sufferers. Potential mechanisms, such as puberty or cognitive biases, can be investigated both in humans and in rodent models of anxiety. This thesis aimed to characterise sex differences and changes in anxiety-like behaviour across adolescence and into adulthood in the rat, and to examine anxiety and interpretive bias in adolescent humans. In rats, we examined performance on common tests of anxiety-like behaviour: the emergence test, open field and elevated plus-maze. Exploration on these tests increased from mid-adolescence into adulthood, and greater exploration by females was apparent from late adolescence. While the behaviours themselves remain interesting, caution on interpreting these behaviours as anxiety-related warranted and is discussed throughout the thesis. Potential effects of the ovarian cycle and testing order on EPM performance were also examined. In humans, 12-14 year old adolescents complete visual and written interpretive bias tasks, this bias being considered to be a cognitive vulnerability for anxiety. The results showed that, when imagining themselves in ambiguous scenarios, girls were more negative in their interpretations than boys. Additionally, both sexes also interpreted social scenarios more negatively than non-social scenarios. As puberty is thought to be important to the emergence of disorder during adolescence, interpretive bias could potentially mediate the puberty-anxiety relationship. While more interpretive bias work is needed in both species, the recent development of interpretive bias tasks for rodents provides an opportunity to move away from difficult to interpret tests of anxiety-like behaviour in rodents, and should allow for greater convergence of the human and rodent anxiety research. 2012-11-30T00:00:00Z Lynn, Debra Alana Anxiety disorders commonly emerge during adolescence, and girls are diagnosed with these disorders more frequently than boys. Understanding why anxiety disorders emerge and why non-clinical anxiety symptoms increase during adolescence is important for understanding this sex difference and how to treat adolescent sufferers. Potential mechanisms, such as puberty or cognitive biases, can be investigated both in humans and in rodent models of anxiety. This thesis aimed to characterise sex differences and changes in anxiety-like behaviour across adolescence and into adulthood in the rat, and to examine anxiety and interpretive bias in adolescent humans. In rats, we examined performance on common tests of anxiety-like behaviour: the emergence test, open field and elevated plus-maze. Exploration on these tests increased from mid-adolescence into adulthood, and greater exploration by females was apparent from late adolescence. While the behaviours themselves remain interesting, caution on interpreting these behaviours as anxiety-related warranted and is discussed throughout the thesis. Potential effects of the ovarian cycle and testing order on EPM performance were also examined. In humans, 12-14 year old adolescents complete visual and written interpretive bias tasks, this bias being considered to be a cognitive vulnerability for anxiety. The results showed that, when imagining themselves in ambiguous scenarios, girls were more negative in their interpretations than boys. Additionally, both sexes also interpreted social scenarios more negatively than non-social scenarios. As puberty is thought to be important to the emergence of disorder during adolescence, interpretive bias could potentially mediate the puberty-anxiety relationship. While more interpretive bias work is needed in both species, the recent development of interpretive bias tasks for rodents provides an opportunity to move away from difficult to interpret tests of anxiety-like behaviour in rodents, and should allow for greater convergence of the human and rodent anxiety research. http://hdl.handle.net/10023/3149 Abstract: Before infants speak their first word, they already produce a large variety of sounds. Whilst the developmental process that leads to speech production is very well documented, little attention is given to how non-linguistic sounds function in the child’s everyday environment and whether they show acoustic consistencies similar to those found in the calls of non-human primates. This thesis investigated whether human infants between 11 and 18 months have “calls”. The first study observed 22 infants in their everyday nursery environment in Scotland and identified a number of contexts in which infants produced vocal behaviour. Vocalisations in five of these contexts, giving, declarative pointing, food requests, protests and action requests, were then subjected to an acoustic analysis. Results of the discriminant analysis suggest that four categories of vocal behaviour can be distinguished on the basis of their acoustic properties alone. To investigate whether these calls are part of a universal human repertoire, we conducted a cross-cultural comparison of the acoustic properties of vocal behaviour showed that, despite a slightly higher level of variation; four categories of calls could still be discriminated above chance level. This suggests that human infants possess calls with rather fixed acoustic properties as part of their vocal repertoire in addition to other, more flexible vocal behaviours. In order to assess whether listeners can gain information from these calls, we conducted a playback study with parents, experienced and inexperienced participants. Results show that all participants can categorise all vocalisations above chance level. Parents were the only participants that showed significantly better scores in correctly classifying vocalisations recorded in Scotland over those recorded in Uganda. Overall, the studies demonstrated that infants, as part of their vocal repertoire, produce some classes of calls that have constant acoustic properties across infants from different cultures, and contain information about the infant’s activities that can be picked up by a listener. 2012-06-19T00:00:00Z Kersken, Verena Before infants speak their first word, they already produce a large variety of sounds. Whilst the developmental process that leads to speech production is very well documented, little attention is given to how non-linguistic sounds function in the child’s everyday environment and whether they show acoustic consistencies similar to those found in the calls of non-human primates. This thesis investigated whether human infants between 11 and 18 months have “calls”. The first study observed 22 infants in their everyday nursery environment in Scotland and identified a number of contexts in which infants produced vocal behaviour. Vocalisations in five of these contexts, giving, declarative pointing, food requests, protests and action requests, were then subjected to an acoustic analysis. Results of the discriminant analysis suggest that four categories of vocal behaviour can be distinguished on the basis of their acoustic properties alone. To investigate whether these calls are part of a universal human repertoire, we conducted a cross-cultural comparison of the acoustic properties of vocal behaviour showed that, despite a slightly higher level of variation; four categories of calls could still be discriminated above chance level. This suggests that human infants possess calls with rather fixed acoustic properties as part of their vocal repertoire in addition to other, more flexible vocal behaviours. In order to assess whether listeners can gain information from these calls, we conducted a playback study with parents, experienced and inexperienced participants. Results show that all participants can categorise all vocalisations above chance level. Parents were the only participants that showed significantly better scores in correctly classifying vocalisations recorded in Scotland over those recorded in Uganda. Overall, the studies demonstrated that infants, as part of their vocal repertoire, produce some classes of calls that have constant acoustic properties across infants from different cultures, and contain information about the infant’s activities that can be picked up by a listener. http://hdl.handle.net/10023/3131 Abstract: My research identifies facial adiposity, a measure of weight in the face, as a novel facial cue to attractiveness and health. Previously identified facial cues, such as symmetry, averageness, sexual dimorphism and skin condition, are not consistently related to indices of actual health. I chapter 2 I demonstrate that facial adiposity is reliably associated with judgements of facial attractiveness and health in Caucasians and also with frequency and duration of respiratory infections, antibiotics use and blood pressure, indicating that facial adiposity is a valid cue to health. Additionally, in chapter 3 I identify three quantifiable facial shape cues that are reliably related to Body Mass Index (BMI) and are used by observers to judge weight in Caucasian and African faces. In chapter 4 I show that Western Caucasian women, but not men, prefer a significantly lower facial adiposity when judging attractiveness than when judging health in other women’s faces. This difference may reflect the influence of the media, since it was only significant in women’s judgements and previous work showed that women internalize media messages about body ideals more than men do. In contrast, African participants in chapter 6 did not show any difference between the optimal facial adiposity for health and attractiveness, which is consistent with the prediction that people living in an environment with a high disease burden will base their concept of attractiveness more closely on cues to health. Importantly, these different patterns of results for Western Caucasian and African participants are unlikely to be due to cultural differences in media ideals of beauty, since the new African body ideal portrayed by the South African media is closely aligned with the Western ideal (chapter 5). Thus, my research suggests that perceptions of facial adiposity may well be influenced by an interaction between environmental factors and media ideals. 2011-01-01T00:00:00Z Coetzee, Vinet My research identifies facial adiposity, a measure of weight in the face, as a novel facial cue to attractiveness and health. Previously identified facial cues, such as symmetry, averageness, sexual dimorphism and skin condition, are not consistently related to indices of actual health. I chapter 2 I demonstrate that facial adiposity is reliably associated with judgements of facial attractiveness and health in Caucasians and also with frequency and duration of respiratory infections, antibiotics use and blood pressure, indicating that facial adiposity is a valid cue to health. Additionally, in chapter 3 I identify three quantifiable facial shape cues that are reliably related to Body Mass Index (BMI) and are used by observers to judge weight in Caucasian and African faces. In chapter 4 I show that Western Caucasian women, but not men, prefer a significantly lower facial adiposity when judging attractiveness than when judging health in other women’s faces. This difference may reflect the influence of the media, since it was only significant in women’s judgements and previous work showed that women internalize media messages about body ideals more than men do. In contrast, African participants in chapter 6 did not show any difference between the optimal facial adiposity for health and attractiveness, which is consistent with the prediction that people living in an environment with a high disease burden will base their concept of attractiveness more closely on cues to health. Importantly, these different patterns of results for Western Caucasian and African participants are unlikely to be due to cultural differences in media ideals of beauty, since the new African body ideal portrayed by the South African media is closely aligned with the Western ideal (chapter 5). Thus, my research suggests that perceptions of facial adiposity may well be influenced by an interaction between environmental factors and media ideals. http://hdl.handle.net/10023/3121 Abstract: The capacity for cumulatively complex and constructive technologies is a hallmark of human cognitive ability. Many species use tools, yet the breadth, adaptability, and inventiveness of human tool use distinguishes us. Such complex technological adaptations require the causal understanding to invent and perfect new techniques and the ability to copy perceived behaviours. This has led to considerable research comparing the social learning abilities of chimpanzees and young children on tool-using tasks, yet experimental studies directly investigating tool modification are rare. The studies outlined in this thesis sought to assess the social learning abilities of chimpanzees and children by manipulating both the complexity of a tool modification method and the amount of information available in a demonstration. Video demonstrations of conspecifics were used in lieu of live models, in order to manipulate the quality and quantity of information directly. Both chimpanzees and children presented with complete information about the modification process learned to combine two tools together to make a more efficient tool significantly more than those provided with less information. Unlike chimpanzees, children presented with a more perceptually opaque method of tool modification (twisting and extending an internal rod) were also able to socially learn the task, despite the fact that none of the children in the control condition successfully solved the task. Both children and chimpanzees who solved the task after seeing a demonstration also persisted in using the socially learned method two-weeks later, even when it was no longer necessary. These results identify potent social learning effects in both chimpanzees and children, however, children proved superior to chimpanzees in observationally learning finer manipulative techniques. This thesis also provides the first analysis of video stimuli in ravens. To assess the feasibility of the methodology, ravens were first presented with different types of video stimuli, varying in terms of the subject identity. Ravens showed a preference for video footage of other ravens over different species of birds. In a second study, ravens who saw a conspecific solve a two-step task were more likely to attempt a solution than those who had not. This represents the first evidence of social learning from a video demonstration in ravens and further supports the use of this medium to dissect social learning mechanisms in a range of species. 2011-01-01T00:00:00Z Price, Elizabeth E. The capacity for cumulatively complex and constructive technologies is a hallmark of human cognitive ability. Many species use tools, yet the breadth, adaptability, and inventiveness of human tool use distinguishes us. Such complex technological adaptations require the causal understanding to invent and perfect new techniques and the ability to copy perceived behaviours. This has led to considerable research comparing the social learning abilities of chimpanzees and young children on tool-using tasks, yet experimental studies directly investigating tool modification are rare. The studies outlined in this thesis sought to assess the social learning abilities of chimpanzees and children by manipulating both the complexity of a tool modification method and the amount of information available in a demonstration. Video demonstrations of conspecifics were used in lieu of live models, in order to manipulate the quality and quantity of information directly. Both chimpanzees and children presented with complete information about the modification process learned to combine two tools together to make a more efficient tool significantly more than those provided with less information. Unlike chimpanzees, children presented with a more perceptually opaque method of tool modification (twisting and extending an internal rod) were also able to socially learn the task, despite the fact that none of the children in the control condition successfully solved the task. Both children and chimpanzees who solved the task after seeing a demonstration also persisted in using the socially learned method two-weeks later, even when it was no longer necessary. These results identify potent social learning effects in both chimpanzees and children, however, children proved superior to chimpanzees in observationally learning finer manipulative techniques. This thesis also provides the first analysis of video stimuli in ravens. To assess the feasibility of the methodology, ravens were first presented with different types of video stimuli, varying in terms of the subject identity. Ravens showed a preference for video footage of other ravens over different species of birds. In a second study, ravens who saw a conspecific solve a two-step task were more likely to attempt a solution than those who had not. This represents the first evidence of social learning from a video demonstration in ravens and further supports the use of this medium to dissect social learning mechanisms in a range of species. http://hdl.handle.net/10023/3112 Abstract: The aim of this thesis is to extend the social identity model of crowd behaviour (Reicher, 1984, 1987, 1996) by exploring the experience of collective participation, with an emphasis upon quality of within-crowd social relations (‘relatedness’) and collective emotionality. A multi-method research strategy is employed to study these topics at a variety of crowd events. Studies 1 and 2 use ethnography and retrospective interviews at a student protest and public screenings of football matches to generate hypotheses for subsequent testing. Study 3 then tests these hypotheses by means of questionnaire data collected during Study 2. Using an experimental ‘visualisation’ paradigm, Study 4 demonstrates the role of shared identity (and not simply self-categorization) in generating relatedness. Studies 5 and 6 present evidence that groups of high relatedness participants experience identity-relevant stimuli as more emotionally intense than low relatedness groups. Study 7 concludes the empirical work by using questionnaire data collected at political protests to test a model of collective experience based upon the findings of the previous studies. The thesis argues that a perception of shared identity with co-present others can positively transform social relations towards relatedness (connectedness, validation and recognition). Relatedness may then be experienced emotionally, and facilitate the realisation of group goals which may also have emotional consequences. Strength of social identity is also noted as an antecedent to group-based emotion. In this way the analysis offers three ways in which social identity may lead to emotionality of collective experience, contradicting ‘classic’ crowd psychology in which crowd emotion was rooted in a loss of identity. Preliminary evidence is also presented suggesting that the experience of collective participation may have a role to play in determining future social identification and participation in co-action. 2012-06-19T00:00:00Z Neville, Fergus Gilmour The aim of this thesis is to extend the social identity model of crowd behaviour (Reicher, 1984, 1987, 1996) by exploring the experience of collective participation, with an emphasis upon quality of within-crowd social relations (‘relatedness’) and collective emotionality. A multi-method research strategy is employed to study these topics at a variety of crowd events. Studies 1 and 2 use ethnography and retrospective interviews at a student protest and public screenings of football matches to generate hypotheses for subsequent testing. Study 3 then tests these hypotheses by means of questionnaire data collected during Study 2. Using an experimental ‘visualisation’ paradigm, Study 4 demonstrates the role of shared identity (and not simply self-categorization) in generating relatedness. Studies 5 and 6 present evidence that groups of high relatedness participants experience identity-relevant stimuli as more emotionally intense than low relatedness groups. Study 7 concludes the empirical work by using questionnaire data collected at political protests to test a model of collective experience based upon the findings of the previous studies. The thesis argues that a perception of shared identity with co-present others can positively transform social relations towards relatedness (connectedness, validation and recognition). Relatedness may then be experienced emotionally, and facilitate the realisation of group goals which may also have emotional consequences. Strength of social identity is also noted as an antecedent to group-based emotion. In this way the analysis offers three ways in which social identity may lead to emotionality of collective experience, contradicting ‘classic’ crowd psychology in which crowd emotion was rooted in a loss of identity. Preliminary evidence is also presented suggesting that the experience of collective participation may have a role to play in determining future social identification and participation in co-action. http://hdl.handle.net/10023/3101 Abstract: The question of animal culture has been of interest for decades. Chimpanzees (Pan troglodytes) have played a key role in the debate of whether or not it is appropriate to use the term ‘culture’ to describe animal behaviour and they continue to be one of the prime species for the study of the origins of human culture. Data suggesting that chimpanzees can be considered a cultural species continue to accumulate, but this has only enhanced the debate between proponents and opponents of animal culture. Opponents do not deny that behavioural diversity exists between different populations of the same species, but they maintain that such phenomena have little to do with human cultures and may be the result of genetic and environmental influences. In their view, human cultures are centred on socially shared sets of ideas, not behavioural traditions. In this thesis, my goal is to tackle this problem and to investigate whether a cognitive dimension can be found in some behavioural patterns of chimpanzees that have been put forward as examples of animal culture. To this end, I examine the different factors that could account for the development of tool use in animals (genetics, ecology, social). My first empirical contribution is a study of the tool use behaviour of the chimpanzees’ closest relative, the bonobos, which are known to be limited tool-users in the wild. I show that captive bonobos are as flexible tool-users as chimpanzees, suggesting that genetic factors are unlikely to account for differences in tool use behaviour in the Pan clade. Second, through the use of field experiments, I show that wild chimpanzees from different Ugandan communities respond to the same apparatus and task in strikingly different ways. I interpret this finding as an outcome of differences in cultural knowledge, mainly because the affordances of their immediate environment do not determine their tool use behaviour. Finally, through a broad ecological and tool use survey of different chimpanzee communities in Uganda, I show that current ecological differences are poor predictors of tool use. I conclude that, if ecology plays a role in the development of tool use, then its influence is that of a selective force. Finally, when reviewing the outcome of this research I will argue that there is a profound cognitive dimension to tool use in wild chimpanzees, suggesting that behaviourally based definitions of animal culture may miss a key feature of the phenomenon, at least in chimpanzees. Chimpanzees are not only a cultural species, they also have a cultural mind. 2011-11-30T00:00:00Z Gruber, Thibaud The question of animal culture has been of interest for decades. Chimpanzees (Pan troglodytes) have played a key role in the debate of whether or not it is appropriate to use the term ‘culture’ to describe animal behaviour and they continue to be one of the prime species for the study of the origins of human culture. Data suggesting that chimpanzees can be considered a cultural species continue to accumulate, but this has only enhanced the debate between proponents and opponents of animal culture. Opponents do not deny that behavioural diversity exists between different populations of the same species, but they maintain that such phenomena have little to do with human cultures and may be the result of genetic and environmental influences. In their view, human cultures are centred on socially shared sets of ideas, not behavioural traditions. In this thesis, my goal is to tackle this problem and to investigate whether a cognitive dimension can be found in some behavioural patterns of chimpanzees that have been put forward as examples of animal culture. To this end, I examine the different factors that could account for the development of tool use in animals (genetics, ecology, social). My first empirical contribution is a study of the tool use behaviour of the chimpanzees’ closest relative, the bonobos, which are known to be limited tool-users in the wild. I show that captive bonobos are as flexible tool-users as chimpanzees, suggesting that genetic factors are unlikely to account for differences in tool use behaviour in the Pan clade. Second, through the use of field experiments, I show that wild chimpanzees from different Ugandan communities respond to the same apparatus and task in strikingly different ways. I interpret this finding as an outcome of differences in cultural knowledge, mainly because the affordances of their immediate environment do not determine their tool use behaviour. Finally, through a broad ecological and tool use survey of different chimpanzee communities in Uganda, I show that current ecological differences are poor predictors of tool use. I conclude that, if ecology plays a role in the development of tool use, then its influence is that of a selective force. Finally, when reviewing the outcome of this research I will argue that there is a profound cognitive dimension to tool use in wild chimpanzees, suggesting that behaviourally based definitions of animal culture may miss a key feature of the phenomenon, at least in chimpanzees. Chimpanzees are not only a cultural species, they also have a cultural mind. http://hdl.handle.net/10023/3077 Abstract: The luminance and colour gradients across an image are the result of complex interactions between object shape, material and illumination. Using such variations to infer object shape or surface colour is therefore a difficult problem for the visual system. We know that changes to the shape of an object can affect its perceived colour, and that shading gradients confer a sense of shape. Here we investigate if the visual system is able to effectively utilise these gradients as a cue to shape perception, even when additional cues are not available. We tested shape perception of a folded card object that contained illumination gradients in the form of shading and more subtle effects such as inter-reflections. Our results suggest that observers are able to use the gradients to make consistent shape judgements. In order to do this, observers must be given the opportunity to learn suitable assumptions about the lighting and scene. Using a variety of different training conditions, we demonstrate that learning can occur quickly and requires only coarse information. We also establish that learning does not deliver a trivial mapping between gradient and shape; rather learning leads to the acquisition of assumptions about lighting and scene parameters that subsequently allow for gradients to be used as a shape cue. The perceived shape is shown to be consistent for convex and concave versions of the object that exhibit very different shading, and also similar to that delivered by outline, a largely unrelated cue to shape. Overall our results indicate that, although gradients are less reliable than some other cues, the relationship between gradients and shape can be quickly assessed and the gradients therefore used effectively as a visual shape cue. 2012-04-30T00:00:00Z Harding, Glen Harris, Julie Bloj, Marina The luminance and colour gradients across an image are the result of complex interactions between object shape, material and illumination. Using such variations to infer object shape or surface colour is therefore a difficult problem for the visual system. We know that changes to the shape of an object can affect its perceived colour, and that shading gradients confer a sense of shape. Here we investigate if the visual system is able to effectively utilise these gradients as a cue to shape perception, even when additional cues are not available. We tested shape perception of a folded card object that contained illumination gradients in the form of shading and more subtle effects such as inter-reflections. Our results suggest that observers are able to use the gradients to make consistent shape judgements. In order to do this, observers must be given the opportunity to learn suitable assumptions about the lighting and scene. Using a variety of different training conditions, we demonstrate that learning can occur quickly and requires only coarse information. We also establish that learning does not deliver a trivial mapping between gradient and shape; rather learning leads to the acquisition of assumptions about lighting and scene parameters that subsequently allow for gradients to be used as a shape cue. The perceived shape is shown to be consistent for convex and concave versions of the object that exhibit very different shading, and also similar to that delivered by outline, a largely unrelated cue to shape. Overall our results indicate that, although gradients are less reliable than some other cues, the relationship between gradients and shape can be quickly assessed and the gradients therefore used effectively as a visual shape cue. http://hdl.handle.net/10023/3066 Abstract: We present an approach to synthesising the effects of ageing on human face images using three-dimensional modelling. We extract a set of three dimensional face models from a set of two-dimensional face images by fitting a Morphable Model. We propose a method to age these face models using Partial Least Squares to extract from the data-set those factors most related to ageing. These ageing related factors are used to train an individually weighted linear model. We show that this is an effective means of producing an aged face image and compare this method to two other linear ageing methods for ageing face models. This is demonstrated both quantitatively and with perceptual evaluation using human raters. 2009-02-01T00:00:00Z Hunter, David William Tiddeman, Bernard Paul We present an approach to synthesising the effects of ageing on human face images using three-dimensional modelling. We extract a set of three dimensional face models from a set of two-dimensional face images by fitting a Morphable Model. We propose a method to age these face models using Partial Least Squares to extract from the data-set those factors most related to ageing. These ageing related factors are used to train an individually weighted linear model. We show that this is an effective means of producing an aged face image and compare this method to two other linear ageing methods for ageing face models. This is demonstrated both quantitatively and with perceptual evaluation using human raters. http://hdl.handle.net/10023/3029 Abstract: I tested two pairs of captive chimpanzees (Pan troglodytes) in the informed forager paradigm: a subordinate saw the location of hidden bait, and then searched with a naïve dominant. This paradigm has tested what subjects know about others’ states of knowledge, but my focus was to determine how subjects used different movement types and different gaze types to modify their competitive tactics. In particular, I investigated whether chimpanzees follow opponents’ gaze to gain information. Learning more about how primates use visual information to predict others’ behaviour can shed light on the continuing debate over to what degree apes possess theory of mind capacities. Previous published studies in this paradigm included narratives of ignorant competitors exploiting informed subjects by following their movement and gaze, and informed subjects avoided this exploitation by walking away from hidden food. The subordinate’s behaviour can be considered tactical deception, which is a good place to seek strong evidence of second-order intentionality. Analyses with descriptive statistics, however, fail to capture the complexity of these interactions, which range from single decision-making points to larger patterns of following and misleading. I introduced a novel method of statistical analysis, cross correlations, that enabled me to examine behavioural patterns quantitatively that previous authors have only been able to describe in narrative form. Though previous studies on chimpanzees’ understanding of gaze found that they were unable to use (human-given) gaze cues to locate hidden food, the subjects I tested followed their conspecific opponent’s gaze, and used information gained from the gaze interaction to modify their own movement towards the hidden bait. Dominants adjusted their physical following of the subordinates as the interaction progressed, which reflected their changed states of knowledge. Subordinates used their movement and gaze differentially to manipulate dominants’ behaviour, by withholding information and by recruiting towards a less-preferred bait. 2012-06-19T00:00:00Z Hall, Katherine McGregor I tested two pairs of captive chimpanzees (Pan troglodytes) in the informed forager paradigm: a subordinate saw the location of hidden bait, and then searched with a naïve dominant. This paradigm has tested what subjects know about others’ states of knowledge, but my focus was to determine how subjects used different movement types and different gaze types to modify their competitive tactics. In particular, I investigated whether chimpanzees follow opponents’ gaze to gain information. Learning more about how primates use visual information to predict others’ behaviour can shed light on the continuing debate over to what degree apes possess theory of mind capacities. Previous published studies in this paradigm included narratives of ignorant competitors exploiting informed subjects by following their movement and gaze, and informed subjects avoided this exploitation by walking away from hidden food. The subordinate’s behaviour can be considered tactical deception, which is a good place to seek strong evidence of second-order intentionality. Analyses with descriptive statistics, however, fail to capture the complexity of these interactions, which range from single decision-making points to larger patterns of following and misleading. I introduced a novel method of statistical analysis, cross correlations, that enabled me to examine behavioural patterns quantitatively that previous authors have only been able to describe in narrative form. Though previous studies on chimpanzees’ understanding of gaze found that they were unable to use (human-given) gaze cues to locate hidden food, the subjects I tested followed their conspecific opponent’s gaze, and used information gained from the gaze interaction to modify their own movement towards the hidden bait. Dominants adjusted their physical following of the subordinates as the interaction progressed, which reflected their changed states of knowledge. Subordinates used their movement and gaze differentially to manipulate dominants’ behaviour, by withholding information and by recruiting towards a less-preferred bait. http://hdl.handle.net/10023/3021 Abstract: Background: Non-human primate communication is thought to be fundamentally different from human speech, mainly due to vast differences in vocal control. The lack of these abilities in non-human primates is especially striking if compared to some marine mammals and bird species, which has generated somewhat of an evolutionary conundrum. What are the biological roots and underlying evolutionary pressures of the human ability to voluntarily control sound production and learn the vocal utterances of others? One hypothesis is that this capacity has evolved gradually in humans from an ancestral stage that resembled the vocal behavior of modern primates. Support for this has come from studies that have documented limited vocal flexibility and convergence in different primate species, typically in calls used during social interactions. The mechanisms underlying these patterns, however, are currently unknown. Specifically, it has been difficult to rule out explanations based on genetic relatedness, suggesting that such vocal flexibility may not be the result of social learning. Results: To address this point, we compared the degree of acoustic similarity of contact calls in free-ranging Campbell's monkeys as a function of their social bonds and genetic relatedness. We calculated three different indices to compare the similarities between the calls' frequency contours, the duration of grooming interactions and the microsatellite-based genetic relatedness between partners. We found a significantly positive relation between bond strength and acoustic similarity that was independent of genetic relatedness. Conclusion: Genetic factors determine the general species-specific call repertoire of a primate species, while social factors can influence the fine structure of some the call types. The finding is in line with the more general hypothesis that human speech has evolved gradually from earlier primate-like vocal communication. 2011-12-16T00:00:00Z Lemasson, Alban Ouattara, Karim Petit, Eric J. Zuberbuhler, Klaus Background: Non-human primate communication is thought to be fundamentally different from human speech, mainly due to vast differences in vocal control. The lack of these abilities in non-human primates is especially striking if compared to some marine mammals and bird species, which has generated somewhat of an evolutionary conundrum. What are the biological roots and underlying evolutionary pressures of the human ability to voluntarily control sound production and learn the vocal utterances of others? One hypothesis is that this capacity has evolved gradually in humans from an ancestral stage that resembled the vocal behavior of modern primates. Support for this has come from studies that have documented limited vocal flexibility and convergence in different primate species, typically in calls used during social interactions. The mechanisms underlying these patterns, however, are currently unknown. Specifically, it has been difficult to rule out explanations based on genetic relatedness, suggesting that such vocal flexibility may not be the result of social learning. Results: To address this point, we compared the degree of acoustic similarity of contact calls in free-ranging Campbell's monkeys as a function of their social bonds and genetic relatedness. We calculated three different indices to compare the similarities between the calls' frequency contours, the duration of grooming interactions and the microsatellite-based genetic relatedness between partners. We found a significantly positive relation between bond strength and acoustic similarity that was independent of genetic relatedness. Conclusion: Genetic factors determine the general species-specific call repertoire of a primate species, while social factors can influence the fine structure of some the call types. The finding is in line with the more general hypothesis that human speech has evolved gradually from earlier primate-like vocal communication. http://hdl.handle.net/10023/3013 Abstract: The notion of animal culture, defined as socially transmitted community-specific behaviour patterns, remains controversial, notably because the definition relies on surface behaviours without addressing underlying cognitive processes. In contrast, human cultures are the product of socially acquired ideas that shape how individuals interact with their environment. We conducted field experiments with two culturally distinct chimpanzee communities in Uganda, which revealed significant differences in how individuals considered the affording parts of an experimentally provided tool to extract honey from a standardised cavity. Firstly, individuals of the two communities found different functional parts of the tool salient, suggesting that they experienced a cultural bias in their cognition. Secondly, when the alternative function was made more salient, chimpanzees were unable to learn it, suggesting that prior cultural background can interfere with new learning. Culture appears to shape how chimpanzees see the world, suggesting that a cognitive component underlies the observed behavioural patterns. 2011-11-03T00:00:00Z Gruber, Thibaud Muller, Martin N. Reynolds, Vernon Wrangham, Richard Zuberbuehler, Klaus The notion of animal culture, defined as socially transmitted community-specific behaviour patterns, remains controversial, notably because the definition relies on surface behaviours without addressing underlying cognitive processes. In contrast, human cultures are the product of socially acquired ideas that shape how individuals interact with their environment. We conducted field experiments with two culturally distinct chimpanzee communities in Uganda, which revealed significant differences in how individuals considered the affording parts of an experimentally provided tool to extract honey from a standardised cavity. Firstly, individuals of the two communities found different functional parts of the tool salient, suggesting that they experienced a cultural bias in their cognition. Secondly, when the alternative function was made more salient, chimpanzees were unable to learn it, suggesting that prior cultural background can interfere with new learning. Culture appears to shape how chimpanzees see the world, suggesting that a cognitive component underlies the observed behavioural patterns. http://hdl.handle.net/10023/3012 Abstract: Bonobo females frequently form close bonds, which give them social power over other group members. One potential mechanism to facilitate female bonding is the performance of sexual interactions. Using naturalistic observations and experiments, we found various patterns that determined female-female sexual interactions. First, while low-ranked females interacted with all females, sexual interactions between high-ranked females were rare. Second, during genital contacts, females sometimes produced 'copulation calls', which were significantly affected by the rank of the caller and partner, as well as the solicitation direction. Third, there was a significant effect of the alpha female as a bystander, while variables relating to physical experience had no effects. Overall, results highlight the importance of sexual interactions for bonobo female social relations. Copulation calls are an important tool during this process, suggesting that they have become ritualised, beyond their reproductive function, to serve as broader social signals in flexible and potentially strategic ways. 2012-03-01T00:00:00Z Clay, Zanna Zuberbuehler, Klaus Bonobo females frequently form close bonds, which give them social power over other group members. One potential mechanism to facilitate female bonding is the performance of sexual interactions. Using naturalistic observations and experiments, we found various patterns that determined female-female sexual interactions. First, while low-ranked females interacted with all females, sexual interactions between high-ranked females were rare. Second, during genital contacts, females sometimes produced 'copulation calls', which were significantly affected by the rank of the caller and partner, as well as the solicitation direction. Third, there was a significant effect of the alpha female as a bystander, while variables relating to physical experience had no effects. Overall, results highlight the importance of sexual interactions for bonobo female social relations. Copulation calls are an important tool during this process, suggesting that they have become ritualised, beyond their reproductive function, to serve as broader social signals in flexible and potentially strategic ways. http://hdl.handle.net/10023/3008 Abstract: Background. Previous behavioural and neuroimaging studies of emotion processing in autistic spectrum disorder (ASD) have focused on the use of facial stimuli. To date, however, no studies have examined emotion processing in autism across a broad range of social signals. Method. This study addressed this issue by investigating emotion processing in a group of 23 adults with ASD and 23 age-and gender-matched controls. Recognition of basic emotions ('happiness ', 'sadness', 'anger', disgust' and 'fear') was assessed from facial, body movement and vocal stimuli. The ability to make social judgements (such as approachability) from facial stimuli was also investigated. Results. Significant deficits in emotion recognition were found in the ASD group relative to the control group across all stimulus domains (faces, body movements and voices). These deficits were seen across a range of emotions. The ASD group were also impaired in making social judgements compared to the control group and this correlated with impairments in basic emotion recognition. Conclusions. This study demonstrates that there are significant and broad-ranging deficits in emotion processing in ASD present across a range of stimulus domains and in the auditory and visual modality; they cannot therefore be accounted for simply in terms of impairments in face processing or in the visual modality alone. These results identify a core deficit affecting the processing of a wide range of emotional information in ASD, which contributes to the impairments in social function seen in people with this condition. 2010-11-01T00:00:00Z Philip, R. C. M. Whalley, H. C. Stanfield, A. C. Sprengelmeyer, R. Santos, I. M. Young, A. W. Atkinson, A. P. Calder, A. J. Johnstone, E. C. Lawrie, S. M. Hall, J. Background. Previous behavioural and neuroimaging studies of emotion processing in autistic spectrum disorder (ASD) have focused on the use of facial stimuli. To date, however, no studies have examined emotion processing in autism across a broad range of social signals. Method. This study addressed this issue by investigating emotion processing in a group of 23 adults with ASD and 23 age-and gender-matched controls. Recognition of basic emotions ('happiness ', 'sadness', 'anger', disgust' and 'fear') was assessed from facial, body movement and vocal stimuli. The ability to make social judgements (such as approachability) from facial stimuli was also investigated. Results. Significant deficits in emotion recognition were found in the ASD group relative to the control group across all stimulus domains (faces, body movements and voices). These deficits were seen across a range of emotions. The ASD group were also impaired in making social judgements compared to the control group and this correlated with impairments in basic emotion recognition. Conclusions. This study demonstrates that there are significant and broad-ranging deficits in emotion processing in ASD present across a range of stimulus domains and in the auditory and visual modality; they cannot therefore be accounted for simply in terms of impairments in face processing or in the visual modality alone. These results identify a core deficit affecting the processing of a wide range of emotional information in ASD, which contributes to the impairments in social function seen in people with this condition. http://hdl.handle.net/10023/2998 Abstract: Background. A wide range of neuropsychiatric conditions, including schizophrenia and autistic spectrum disorder (ASD), are associated with impairments in social function. Previous studies have shown that individuals with schizophrenia and ASD have deficits in making a wide range of social judgements from faces, including decisions related to threat (such as judgements of approachability) and decisions not related to physical threat (such as judgements of intelligence). We have investigated healthy control participants to see whether there is a common neural system activated during such social decisions, on the basis that deficits in this system may contribute to the impairments seen in these disorders. Method. We investigated the neural basis of social decision making during judgements of approachability and intelligence from faces in 24 healthy participants using functional magnetic resonance imaging (fMRI). We used conjunction analysis to identify common brain regions activated during both tasks. Results. Activation of the amygdala, medial prefrontal cortex, inferior prefrontal cortex and cerebellum was seen during performance of both social tasks, compared to simple gender judgements from the same stimuli. Task-specific activations were present in the dorsolateral prefrontal cortex in the intelligence task and in the inferior and middle temporal cortex in the approachability task. Conclusions. The present study identified a common network of brain regions activated during the performance of two different forms of social judgement from faces. Dysfunction of this network is likely to contribute to the broad-ranging deficits in social function seen in psychiatric disorders such as schizophrenia and ASD. 2010-07-01T00:00:00Z Hall, J. Whalley, H. C. McKirdy, J. W. Sprengelmeyer, R. Santos, I. M. Donaldson, D. I. McGonigle, D. J. Young, A. W. McIntosh, A. M. Johnstone, E. C. Lawrie, S. M. Background. A wide range of neuropsychiatric conditions, including schizophrenia and autistic spectrum disorder (ASD), are associated with impairments in social function. Previous studies have shown that individuals with schizophrenia and ASD have deficits in making a wide range of social judgements from faces, including decisions related to threat (such as judgements of approachability) and decisions not related to physical threat (such as judgements of intelligence). We have investigated healthy control participants to see whether there is a common neural system activated during such social decisions, on the basis that deficits in this system may contribute to the impairments seen in these disorders. Method. We investigated the neural basis of social decision making during judgements of approachability and intelligence from faces in 24 healthy participants using functional magnetic resonance imaging (fMRI). We used conjunction analysis to identify common brain regions activated during both tasks. Results. Activation of the amygdala, medial prefrontal cortex, inferior prefrontal cortex and cerebellum was seen during performance of both social tasks, compared to simple gender judgements from the same stimuli. Task-specific activations were present in the dorsolateral prefrontal cortex in the intelligence task and in the inferior and middle temporal cortex in the approachability task. Conclusions. The present study identified a common network of brain regions activated during the performance of two different forms of social judgement from faces. Dysfunction of this network is likely to contribute to the broad-ranging deficits in social function seen in psychiatric disorders such as schizophrenia and ASD. http://hdl.handle.net/10023/2995 Description: XIII Conference of the European Society of Cognitive Psychology (ESCOP-2003), Granada, Spain 2003-01-01T00:00:00Z Foldiak, Peter http://hdl.handle.net/10023/2994 2003-01-01T00:00:00Z Foldiak, Peter http://hdl.handle.net/10023/2993 Abstract: This paper proposes a novel application of Formal Concept Analysis (FCA) to neural decoding: the semantic relationships between the neural representations of large sets of stimuli are explored using concept lattices. In particular, the effects of neural code sparsity are modelled using the lattices. An exact Bayesian approach is employed to construct the formal context needed by FCA. This method is explained using an example of neurophysiological data from the high-level visual cortical area STSa. Prominent features of the resulting concept lattices are discussed, including indications for a product-of-experts code in real neurons. 2008-01-01T00:00:00Z Endres, D M Foldiak, Peter Priss, U This paper proposes a novel application of Formal Concept Analysis (FCA) to neural decoding: the semantic relationships between the neural representations of large sets of stimuli are explored using concept lattices. In particular, the effects of neural code sparsity are modelled using the lattices. An exact Bayesian approach is employed to construct the formal context needed by FCA. This method is explained using an example of neurophysiological data from the high-level visual cortical area STSa. Prominent features of the resulting concept lattices are discussed, including indications for a product-of-experts code in real neurons. http://hdl.handle.net/10023/2992 2007-09-29T00:00:00Z Foldiak, Peter Endres, Dominik Maria http://hdl.handle.net/10023/2991 Abstract: We propose a novel application of Formal Concept Analysis (FCA) to neural decoding: instead of just trying to figure out which stimulus was presented, we demonstrate how to explore the semantic relationships in the neural representation of large sets of stimuli. FCA provides a way of displaying and interpreting such relationships via concept lattices. We explore the effects of neural code sparsity on the lattice. We then analyze neurophysiological data from high-level visual cortical area STSa, using an exact Bayesian approach to construct the formal context needed by FCA. Prominent features of the resulting concept lattices are discussed, including hierarchical face representation and indications for a product-of-experts code in real neurons. Description: This contribution is in volume 1 of 3 for this title. 2009-01-01T00:00:00Z Endres, D Foldiak, Peter We propose a novel application of Formal Concept Analysis (FCA) to neural decoding: instead of just trying to figure out which stimulus was presented, we demonstrate how to explore the semantic relationships in the neural representation of large sets of stimuli. FCA provides a way of displaying and interpreting such relationships via concept lattices. We explore the effects of neural code sparsity on the lattice. We then analyze neurophysiological data from high-level visual cortical area STSa, using an exact Bayesian approach to construct the formal context needed by FCA. Prominent features of the resulting concept lattices are discussed, including hierarchical face representation and indications for a product-of-experts code in real neurons. http://hdl.handle.net/10023/2985 Abstract: Researchers have described multilevel societies with one-male, multifemale units (OMUs) forming within a larger group in several catarrhine species, but not in platyrhines. OMUs in multilevel societies are associated with extremely large group sizes, often with >100 individuals, and the only platyrhine genus that forms groups of this size is Cacajao. We review available evidence for multilevel organization and the formation of OMUs in groups of Cacajao, and test predictions for the frequency distribution patterns of male–male and male–female interindividual distances within groups of red-faced uakaris (Cacajao calvus ucayalii), comparing year-round data with those collected at the peak of the breeding season, when group cohesion may be more pronounced. Groups of Cacajao fission and fuse, forming subgroup sizes at frequencies consistent with an OMU organization. In Cacajao calvus ucayalii and Cacajao calvus calvus, bachelor groups are also observed, a characteristic of several catarrhine species that form OMUs. However, researchers have observed both multimale–multifemale groups and groups with a single male and multiple females in Cacajao calvus. The frequency distributions of interindividual distances for male–male and male–female dyads are consistent with an OMU-based organization, but alternative interpretations of these data are possible. The distribution of interindividual distances collected during the peak breeding season differed from those collected year-round, indicating seasonal changes in the spatial organization of Cacajao calvus ucayalii. We suggest a high degree of flexibility may characterize the social organization of Cacajao calvus ucayalii, which may form OMUs under certain conditions. Further studies with identifiable individuals, thus far not possible in Cacajao, are required to confirm the social organization. 2012-01-01T00:00:00Z Bowler, Mark Timothy Knogge, C Heymann, Eckhard Zinner, D Researchers have described multilevel societies with one-male, multifemale units (OMUs) forming within a larger group in several catarrhine species, but not in platyrhines. OMUs in multilevel societies are associated with extremely large group sizes, often with >100 individuals, and the only platyrhine genus that forms groups of this size is Cacajao. We review available evidence for multilevel organization and the formation of OMUs in groups of Cacajao, and test predictions for the frequency distribution patterns of male–male and male–female interindividual distances within groups of red-faced uakaris (Cacajao calvus ucayalii), comparing year-round data with those collected at the peak of the breeding season, when group cohesion may be more pronounced. Groups of Cacajao fission and fuse, forming subgroup sizes at frequencies consistent with an OMU organization. In Cacajao calvus ucayalii and Cacajao calvus calvus, bachelor groups are also observed, a characteristic of several catarrhine species that form OMUs. However, researchers have observed both multimale–multifemale groups and groups with a single male and multiple females in Cacajao calvus. The frequency distributions of interindividual distances for male–male and male–female dyads are consistent with an OMU-based organization, but alternative interpretations of these data are possible. The distribution of interindividual distances collected during the peak breeding season differed from those collected year-round, indicating seasonal changes in the spatial organization of Cacajao calvus ucayalii. We suggest a high degree of flexibility may characterize the social organization of Cacajao calvus ucayalii, which may form OMUs under certain conditions. Further studies with identifiable individuals, thus far not possible in Cacajao, are required to confirm the social organization. http://hdl.handle.net/10023/2983 Abstract: Formal language theory has been extended to two-dimensional patterns, but little is known about two-dimensional pattern perception. We first examined spontaneous two-dimensional visual pattern production by humans, gathered using a novel touch screen approach. Both spontaneous creative production and subsequent aesthetic ratings show that humans prefer ordered, symmetrical patterns over random patterns. We then further explored pattern-parsing abilities in different human groups, and compared them with pigeons. We generated visual plane patterns based on rules varying in complexity. All human groups tested, including children and individuals diagnosed with autism spectrum disorder (ASD), were able to detect violations of all production rules tested. Our ASD participants detected pattern violations with the same speed and accuracy as matched controls. Children's ability to detect violations of a relatively complex rotational rule correlated with age, whereas their ability to detect violations of a simple translational rule did not. By contrast, even with extensive training, pigeons were unable to detect orientation-based structural violations, suggesting that, unlike humans, they did not learn the underlying structural rules. Visual two-dimensional patterns offer a promising new formally-grounded way to investigate pattern production and perception in general, widely applicable across species and age groups. 2012-07-19T00:00:00Z Westphal, Gesche Huber, Ludwig Gomez, Juan-Carlos Fitch, William Tecumseh Sherman Formal language theory has been extended to two-dimensional patterns, but little is known about two-dimensional pattern perception. We first examined spontaneous two-dimensional visual pattern production by humans, gathered using a novel touch screen approach. Both spontaneous creative production and subsequent aesthetic ratings show that humans prefer ordered, symmetrical patterns over random patterns. We then further explored pattern-parsing abilities in different human groups, and compared them with pigeons. We generated visual plane patterns based on rules varying in complexity. All human groups tested, including children and individuals diagnosed with autism spectrum disorder (ASD), were able to detect violations of all production rules tested. Our ASD participants detected pattern violations with the same speed and accuracy as matched controls. Children's ability to detect violations of a relatively complex rotational rule correlated with age, whereas their ability to detect violations of a simple translational rule did not. By contrast, even with extensive training, pigeons were unable to detect orientation-based structural violations, suggesting that, unlike humans, they did not learn the underlying structural rules. Visual two-dimensional patterns offer a promising new formally-grounded way to investigate pattern production and perception in general, widely applicable across species and age groups. http://hdl.handle.net/10023/2942 Abstract: This observational and experimental study takes the Intersubjectivity Theory of Rogers and Pennington (1991), as the guiding line by which to investigate imitation in autism. A deficit in imitation in early childhood is the principal aspect of this theory which distinguishes it from other major theories such as those of Baron- Cohen et al. (1985) and Hobson (1986). With much debate over the existence of a general deficit in imitation, this study aimed first to test for different types of imitation (including those differentiated by Piaget (1962), such as vocal, immediate and deferred imitation) and second, to examine other deficits linked to imitation in Roger and Pennington's theory - emotion perception, joint attention, theory of mind and play. The effect of age was also investigated. Rogers and Pennington (1991) predicted that young autistic children would show a profile of deficits including impaired imitation, emotion sharing, joint attention and pretend play while older children and adults would show impaired "theory of mind", emotion sharing and language pragmatics, relative to controls. In an observational study autistic children and adults showed less social interaction with peers, more manipulative play, less symbolic play in some comparisons and less evidence of mental state understanding but few differences in imitation, compared to children with learning disabilities and normal 3-4 year old and 5-6 year old children. Virtually the same samples were then tested experimentally for the ability to imitate. This was done for (1) elicited imitation (including vocal, simple body movements and symbolic actions, with and without objects), (2) spontaneous, problem-solving imitation and (3) deferred imitation. In addition, spontaneous, elicited and instructed play was tested and visual perspective-taking, joint attention, false-belief and emotion recognition. No general deficit for imitation in school-age autistic children and autistic adults was found, although a younger group (CA 4 - 7 years) of autistic children did significantly worse on all aspects of the task. Scores were lower on deferred imitation and on spontaneous, problem-solving imitation for the autistic groups and certain categories of actions in the elicited task proved more difficult for the autistic children, namely those requiring symbolic ability. Previous findings on joint attention, false-belief and emotion perception were, for the most part, confirmed, although no links between any of these behaviours and imitation were evident from examination of individual profiles. In addition, a picture of inconsistency across tasks emerged. However, some evidence was found for Rogers and Pennington's theory at a crude level, in that it was the youngest children who had most problems with imitation, symbolic play, and emotion recognition, relative to controls. It is concluded that although imitation may be lacking in early autistic development, Rogers and Pennington's theory may not be an altogether satisfactory way of explaining its contribution to the autistic disorder and is, in fact, very difficult to test. 1996-01-01T00:00:00Z Brown, Julie D. This observational and experimental study takes the Intersubjectivity Theory of Rogers and Pennington (1991), as the guiding line by which to investigate imitation in autism. A deficit in imitation in early childhood is the principal aspect of this theory which distinguishes it from other major theories such as those of Baron- Cohen et al. (1985) and Hobson (1986). With much debate over the existence of a general deficit in imitation, this study aimed first to test for different types of imitation (including those differentiated by Piaget (1962), such as vocal, immediate and deferred imitation) and second, to examine other deficits linked to imitation in Roger and Pennington's theory - emotion perception, joint attention, theory of mind and play. The effect of age was also investigated. Rogers and Pennington (1991) predicted that young autistic children would show a profile of deficits including impaired imitation, emotion sharing, joint attention and pretend play while older children and adults would show impaired "theory of mind", emotion sharing and language pragmatics, relative to controls. In an observational study autistic children and adults showed less social interaction with peers, more manipulative play, less symbolic play in some comparisons and less evidence of mental state understanding but few differences in imitation, compared to children with learning disabilities and normal 3-4 year old and 5-6 year old children. Virtually the same samples were then tested experimentally for the ability to imitate. This was done for (1) elicited imitation (including vocal, simple body movements and symbolic actions, with and without objects), (2) spontaneous, problem-solving imitation and (3) deferred imitation. In addition, spontaneous, elicited and instructed play was tested and visual perspective-taking, joint attention, false-belief and emotion recognition. No general deficit for imitation in school-age autistic children and autistic adults was found, although a younger group (CA 4 - 7 years) of autistic children did significantly worse on all aspects of the task. Scores were lower on deferred imitation and on spontaneous, problem-solving imitation for the autistic groups and certain categories of actions in the elicited task proved more difficult for the autistic children, namely those requiring symbolic ability. Previous findings on joint attention, false-belief and emotion perception were, for the most part, confirmed, although no links between any of these behaviours and imitation were evident from examination of individual profiles. In addition, a picture of inconsistency across tasks emerged. However, some evidence was found for Rogers and Pennington's theory at a crude level, in that it was the youngest children who had most problems with imitation, symbolic play, and emotion recognition, relative to controls. It is concluded that although imitation may be lacking in early autistic development, Rogers and Pennington's theory may not be an altogether satisfactory way of explaining its contribution to the autistic disorder and is, in fact, very difficult to test. http://hdl.handle.net/10023/2894 Abstract: It is contended that space can act as a metaphor for social relationships. The thesis draws on schema theory from cognitive psychology to explain how the affective qualities of social stimuli serve to bias the 'cognitive maps' of individuals. Supporting evidence is cited from the fields of cognitive, social, environmental and neuro-psychology. The metaphor is tested experimentally from a micro-spatial level (e. g. spatial locations of characters in a photograph) up to a macro-spatial level (spatial locations of towns). The affective valence of the stimuli used were either a priori based (e. g. homes of people already known to the subject, perceived religious predominance of towns in a sectarian setting) or influenced by the experimenter (e. g. captions purporting to inform representations of social scenes in photographs derived from newspapers and magazines). Distortion of perceived distances (between subject and stimuli and between stimuli) form the dependent variable in each experiment. Results in all experiments indicated a strong tendency for the valence of stimuli to bias people in their distance estimations. Relative overestimation of distance was observed for stimuli perceived to be negatively valenced and the reverse for those stimuli perceived to be positively valenced. In a final experiment, distance estimations were examined between a variety of human figures photographed in 'real-world' social encounters. The results were in line with Social Identity Theory, with overestimation observed between groups and underestimation within groups. Results throughout are interpreted in relation to the 'socio-spatial schema' metaphor. 1999-01-01T00:00:00Z MacBride, S. J. C. It is contended that space can act as a metaphor for social relationships. The thesis draws on schema theory from cognitive psychology to explain how the affective qualities of social stimuli serve to bias the 'cognitive maps' of individuals. Supporting evidence is cited from the fields of cognitive, social, environmental and neuro-psychology. The metaphor is tested experimentally from a micro-spatial level (e. g. spatial locations of characters in a photograph) up to a macro-spatial level (spatial locations of towns). The affective valence of the stimuli used were either a priori based (e. g. homes of people already known to the subject, perceived religious predominance of towns in a sectarian setting) or influenced by the experimenter (e. g. captions purporting to inform representations of social scenes in photographs derived from newspapers and magazines). Distortion of perceived distances (between subject and stimuli and between stimuli) form the dependent variable in each experiment. Results in all experiments indicated a strong tendency for the valence of stimuli to bias people in their distance estimations. Relative overestimation of distance was observed for stimuli perceived to be negatively valenced and the reverse for those stimuli perceived to be positively valenced. In a final experiment, distance estimations were examined between a variety of human figures photographed in 'real-world' social encounters. The results were in line with Social Identity Theory, with overestimation observed between groups and underestimation within groups. Results throughout are interpreted in relation to the 'socio-spatial schema' metaphor. http://hdl.handle.net/10023/2893 Abstract: Prolonged exposure to visual stimuli, or adaptation, often results in an adaptation “aftereffect” which can profoundly distort our perception of subsequent visual stimuli. This technique has been commonly used to investigate mechanisms underlying our perception of simple visual stimuli, and more recently, of static faces. We tested whether humans would adapt to movies of hands grasping and placing different weight objects. After adapting to hands grasping light or heavy objects, subsequently perceived objects appeared relatively heavier, or lighter, respectively. The aftereffects increased logarithmically with adaptation action repetition and decayed logarithmically with time. Adaptation aftereffects also indicated that perception of actions relies predominantly on view-dependent mechanisms. Adapting to one action significantly influenced the perception of the opposite action. These aftereffects can only be explained by adaptation of mechanisms that take into account the presence/absence of the object in the hand. We tested if evidence on action processing mechanisms obtained using visual adaptation techniques confirms underlying neural processing. We recorded monkey superior temporal sulcus (STS) single-cell responses to hand actions. Cells sensitive to grasping or placing typically responded well to the opposite action; cells also responded during different phases of the actions. Cell responses were sensitive to the view of the action and were dependent upon the presence of the object in the scene. We show here that action processing mechanisms established using visual adaptation parallel the neural mechanisms revealed during recording from monkey STS. Visual adaptation techniques can thus be usefully employed to investigate brain mechanisms underlying action perception. 2009-09-01T00:00:00Z Barraclough, Nicholas Edward Keith, R H Xiao, Dengke Oram, Michael William Perrett, David Ian Prolonged exposure to visual stimuli, or adaptation, often results in an adaptation “aftereffect” which can profoundly distort our perception of subsequent visual stimuli. This technique has been commonly used to investigate mechanisms underlying our perception of simple visual stimuli, and more recently, of static faces. We tested whether humans would adapt to movies of hands grasping and placing different weight objects. After adapting to hands grasping light or heavy objects, subsequently perceived objects appeared relatively heavier, or lighter, respectively. The aftereffects increased logarithmically with adaptation action repetition and decayed logarithmically with time. Adaptation aftereffects also indicated that perception of actions relies predominantly on view-dependent mechanisms. Adapting to one action significantly influenced the perception of the opposite action. These aftereffects can only be explained by adaptation of mechanisms that take into account the presence/absence of the object in the hand. We tested if evidence on action processing mechanisms obtained using visual adaptation techniques confirms underlying neural processing. We recorded monkey superior temporal sulcus (STS) single-cell responses to hand actions. Cells sensitive to grasping or placing typically responded well to the opposite action; cells also responded during different phases of the actions. Cell responses were sensitive to the view of the action and were dependent upon the presence of the object in the scene. We show here that action processing mechanisms established using visual adaptation parallel the neural mechanisms revealed during recording from monkey STS. Visual adaptation techniques can thus be usefully employed to investigate brain mechanisms underlying action perception. http://hdl.handle.net/10023/2835 Abstract: A 12-month study of the ranging behaviour of 11 spider monkeys (Ateles geoffroyi yucatanensis) was undertaken at the Otochma' ax Yetel Kooh nature reserve in the state of Yucatan, Mexico. The aims were: 1) to evaluate the relationship between ranging patterns of the monkeys and ecological features i.e. climate and food distribution, 2) to assess the efficiency of ranging patterns, and 3) to test the hypothesis that spider monkeys navigate between important sources through spatial memory of key locations. A focal animal was followed daily for as long as possible and details of its ranging patterns recorded by entering positional fixes with a GPS receiver. Behavioural states were included in the observations to link them with the geographical information recorded simultaneously. The results revealed that the ranging patterns of spider monkeys at the study site were determined by the availability of key species of fruit in the area. Ranging was efficient, as evidenced by the fact that in most instances - particularly in the dry season when food was scarce - (1) spider monkeys moved in straight lines to distant food sources, (2) were able to orient their movement toward a food source at distances that could not have been in sight from the point where directed movement originated, and (3) the successive organisation of these linear segments was consistently forward, suggesting an ability to plan ahead of the next food source visited. I present these results as evidence of the use of spatial memory to move efficiently between important sources in their environment, and I argue in favour of higher-level spatial abilities in this species of New World monkeys. 2004-01-01T00:00:00Z Valero, Alejandra A 12-month study of the ranging behaviour of 11 spider monkeys (Ateles geoffroyi yucatanensis) was undertaken at the Otochma' ax Yetel Kooh nature reserve in the state of Yucatan, Mexico. The aims were: 1) to evaluate the relationship between ranging patterns of the monkeys and ecological features i.e. climate and food distribution, 2) to assess the efficiency of ranging patterns, and 3) to test the hypothesis that spider monkeys navigate between important sources through spatial memory of key locations. A focal animal was followed daily for as long as possible and details of its ranging patterns recorded by entering positional fixes with a GPS receiver. Behavioural states were included in the observations to link them with the geographical information recorded simultaneously. The results revealed that the ranging patterns of spider monkeys at the study site were determined by the availability of key species of fruit in the area. Ranging was efficient, as evidenced by the fact that in most instances - particularly in the dry season when food was scarce - (1) spider monkeys moved in straight lines to distant food sources, (2) were able to orient their movement toward a food source at distances that could not have been in sight from the point where directed movement originated, and (3) the successive organisation of these linear segments was consistently forward, suggesting an ability to plan ahead of the next food source visited. I present these results as evidence of the use of spatial memory to move efficiently between important sources in their environment, and I argue in favour of higher-level spatial abilities in this species of New World monkeys. http://hdl.handle.net/10023/2833 Abstract: Before this study, the Guinea or Western baboon, Papio papio, was almost unknown in its natural environment. This thesis reports a nineteen-month field study of two troops of P. papio carried out in south-eastern Senegal. The monkeys were followed on foot, and aspects of their feeding, ranging and social behaviour were recorded. The troops were censused whenever possible. Both study groups, and other troops in the area, were found to be unusually large by comparison with other known troops in the genus, and although their age-sex compositions were not exceptional, there was some indication that recruitment into the adult population was low. The activity budgets of both troops were similar, and members of both troops spent more time moving and feeding in the dry season than they did in the wet, when they spent more time in social behaviour. These differences were probably related to seasonal changes in productivity, which were large, since no rain feel in six months of the year. The home range of one of the study troops covered about 45 to 50 square kilometres, while the other troop, whose home range was less well known, ranged over about 18 to 20 square kilometres. There were no seasonal differences in the mean distance travelled per day by either troop, although there was great daily variation about the mean of roughly 8 kilometres. This distance was greater than that travelled by most other troops of baboons, and was ascribed to low productivity in the dry season and large troops in the wet. The troops visited some habitats more frequently than they did others, and moved more slowly through those that they visited frequently than through those that they visited frequently than through those they visited less frequently. In the dry season both troops visited areas in which there was relatively dense shade more frequently than they did areas with little shade. In the wet season they avoided areas in which variability was poor. Sleeping sites were found to have a profound influence on the ranging patterns of the baboons, with usage of the home ranges being inversely proportional to the square of the distance from the nearest sleeping site. The baboons apparently chose to sleep in trees which afforded them protection against predation. The sleeping sites were restricted to places in which there was permanent water. The baboons were largely frugivorous. In this they resembled baboon troops studied in other areas. Their diet changed throughout the year, as various plants fruited or seeded, and was more diverse in the wet season, when a wider variety of foods was available. More than a hundred different food items were known to be eaten, and the number of known food types increased throughout the study. Animals in their diet were mostly invertebrates found beneath boulders, but some vertebrates were also eaten. The social organisation and mating system of these baboons were compared with those of the other baboons, including Theropithecus gelada. It was unlikely that they lived in a society in which adult females were constrained to mate with only one male, as are females in two other species of baboon. Instead, there appeared to be competition for sexual partners, with the formation of consortships between adults during the time of the female’s oestrus. Adult males groomed each other in this species, which is uncommon in baboons with competitive mating, except at times of stress. 1982-01-01T00:00:00Z Sharman, Martin John Before this study, the Guinea or Western baboon, Papio papio, was almost unknown in its natural environment. This thesis reports a nineteen-month field study of two troops of P. papio carried out in south-eastern Senegal. The monkeys were followed on foot, and aspects of their feeding, ranging and social behaviour were recorded. The troops were censused whenever possible. Both study groups, and other troops in the area, were found to be unusually large by comparison with other known troops in the genus, and although their age-sex compositions were not exceptional, there was some indication that recruitment into the adult population was low. The activity budgets of both troops were similar, and members of both troops spent more time moving and feeding in the dry season than they did in the wet, when they spent more time in social behaviour. These differences were probably related to seasonal changes in productivity, which were large, since no rain feel in six months of the year. The home range of one of the study troops covered about 45 to 50 square kilometres, while the other troop, whose home range was less well known, ranged over about 18 to 20 square kilometres. There were no seasonal differences in the mean distance travelled per day by either troop, although there was great daily variation about the mean of roughly 8 kilometres. This distance was greater than that travelled by most other troops of baboons, and was ascribed to low productivity in the dry season and large troops in the wet. The troops visited some habitats more frequently than they did others, and moved more slowly through those that they visited frequently than through those that they visited frequently than through those they visited less frequently. In the dry season both troops visited areas in which there was relatively dense shade more frequently than they did areas with little shade. In the wet season they avoided areas in which variability was poor. Sleeping sites were found to have a profound influence on the ranging patterns of the baboons, with usage of the home ranges being inversely proportional to the square of the distance from the nearest sleeping site. The baboons apparently chose to sleep in trees which afforded them protection against predation. The sleeping sites were restricted to places in which there was permanent water. The baboons were largely frugivorous. In this they resembled baboon troops studied in other areas. Their diet changed throughout the year, as various plants fruited or seeded, and was more diverse in the wet season, when a wider variety of foods was available. More than a hundred different food items were known to be eaten, and the number of known food types increased throughout the study. Animals in their diet were mostly invertebrates found beneath boulders, but some vertebrates were also eaten. The social organisation and mating system of these baboons were compared with those of the other baboons, including Theropithecus gelada. It was unlikely that they lived in a society in which adult females were constrained to mate with only one male, as are females in two other species of baboon. Instead, there appeared to be competition for sexual partners, with the formation of consortships between adults during the time of the female’s oestrus. Adult males groomed each other in this species, which is uncommon in baboons with competitive mating, except at times of stress. http://hdl.handle.net/10023/2828 Abstract: The mesoaccumbens dopamine system has been implicated in many basic psychological processes (e.g. "wanting" and "liking") and illnesses (e.g. addiction, depression, schizophrenia). However, the precise computational functions of nucleus accumbens and dopamine neurons within the system remain unknown. In this thesis, we test some of the current hypotheses regarding the function of this system using a behavioural neurophysiology approach in the rat. The first question we wanted to answer was whether nucleus accumbens neurons process reward-predictive stimuli (e.g. conditioned reinforcers) and reward delivery differently, since previous studies report equivocal findings. To do so, we trained thirsty rats to bar-press on a second-order schedule of saccharin reinforcement, within which the temporal pattern of rats' bar-pressing was reinforced by presentations of a conditioned reinforcer and primary reinforcer (reward). We found that nucleus accumbens neurons typically responded to these conditioned and primary reinforcers with opposite sign, which suggests they were processed differently. We were not sure whether responses to conditioned reinforcers encoded reward-prediction or facilitated a behavioural switch in the rat's behaviour. Indeed, since studies using a variety of experimental techniques have implicated the mesoaccumbens dopamine system in both reward prediction and behavioural switching, we sought to test whether neurons in the nucleus accumbens and dopamine-rich areas of the midbrain respond to outcome-associated stimuli to predict reward or switch behaviour. We found both sets of neurons predominantly did the former. Finally, to understand more about reward consummatory responses from both sets of neurons, we developed a rat behavioural task providing measures of reward "wanting" and "liking". In conclusion, on the basis of our data, the most parsimonious explanation for the function of the mesoaccumbens dopamine system is that it acts to modulate goal-seeking behaviour. Further research is required to identify the function of the interactions between nucleus accumbens and dopamine neurons during goal-seeking and goal consumption. 2005-01-01T00:00:00Z Wilson, David I. G. The mesoaccumbens dopamine system has been implicated in many basic psychological processes (e.g. "wanting" and "liking") and illnesses (e.g. addiction, depression, schizophrenia). However, the precise computational functions of nucleus accumbens and dopamine neurons within the system remain unknown. In this thesis, we test some of the current hypotheses regarding the function of this system using a behavioural neurophysiology approach in the rat. The first question we wanted to answer was whether nucleus accumbens neurons process reward-predictive stimuli (e.g. conditioned reinforcers) and reward delivery differently, since previous studies report equivocal findings. To do so, we trained thirsty rats to bar-press on a second-order schedule of saccharin reinforcement, within which the temporal pattern of rats' bar-pressing was reinforced by presentations of a conditioned reinforcer and primary reinforcer (reward). We found that nucleus accumbens neurons typically responded to these conditioned and primary reinforcers with opposite sign, which suggests they were processed differently. We were not sure whether responses to conditioned reinforcers encoded reward-prediction or facilitated a behavioural switch in the rat's behaviour. Indeed, since studies using a variety of experimental techniques have implicated the mesoaccumbens dopamine system in both reward prediction and behavioural switching, we sought to test whether neurons in the nucleus accumbens and dopamine-rich areas of the midbrain respond to outcome-associated stimuli to predict reward or switch behaviour. We found both sets of neurons predominantly did the former. Finally, to understand more about reward consummatory responses from both sets of neurons, we developed a rat behavioural task providing measures of reward "wanting" and "liking". In conclusion, on the basis of our data, the most parsimonious explanation for the function of the mesoaccumbens dopamine system is that it acts to modulate goal-seeking behaviour. Further research is required to identify the function of the interactions between nucleus accumbens and dopamine neurons during goal-seeking and goal consumption. http://hdl.handle.net/10023/2803 Abstract: Children's thinking has been described by Piaget and others in general terms, which suggest that there are major developmental changes that affect children's thinking at various stages of their development. Some criticisms of Piaget's theory have related to his approach to describing children's thinking as a context free phenomenon. In relation to this point, arguments have been put forward for the need to investigate the development of children's thinking, within particular content areas, and the investigations reported in this thesis have concentrated on the development of religious thinking of children aged from ~6 to 11 years. A review of previous investigations into this area of children's thought development reveals major shortcomings, both in the experimental approaches used and in the theories that have been constructed. In particular it is argued that there has been a tendency for investigators to propose stage development theories on the basis of inadequate results. It is argued that there is a need for investigations which approach this problem from new directions. As a first step, a series of investigations, which employ a variety of approaches and which investigate various cognitive and semantic factors that may influence the development of religious thinking in children, are presented. The investigations that are reported involved individual interviews with 440 children, in the age range from 6 to 11 years. A variety of experimental techniques were employed, including those investigating the children's understanding of various biblical parables, their understanding of the meaning of words used in religious discourse, their conception of historical time and ability to sequentially order events in time, and the way that these factors affected their understanding of religious ideas. The results of the investigations are discussed in terms of the variety of aspects, which they reveal, relating to the development of religious thinking in children. It is argued that this evidence does not support the idea of the development of religious thinking being a unidimensional stage related process; however, the evidence collected from these studies is insufficient to form the basis of an alternative model. It is argued that future studies that follow this approach will be necessary if a satisfactory theory is to be constructed. The educational implications of these findings are discussed and it is argued that certain curriculum changes in the area of religious education may have been made on the basis of insufficient evidence and inadequate theories. 1979-01-01T00:00:00Z Murphy, Roger John Lloyd Children's thinking has been described by Piaget and others in general terms, which suggest that there are major developmental changes that affect children's thinking at various stages of their development. Some criticisms of Piaget's theory have related to his approach to describing children's thinking as a context free phenomenon. In relation to this point, arguments have been put forward for the need to investigate the development of children's thinking, within particular content areas, and the investigations reported in this thesis have concentrated on the development of religious thinking of children aged from ~6 to 11 years. A review of previous investigations into this area of children's thought development reveals major shortcomings, both in the experimental approaches used and in the theories that have been constructed. In particular it is argued that there has been a tendency for investigators to propose stage development theories on the basis of inadequate results. It is argued that there is a need for investigations which approach this problem from new directions. As a first step, a series of investigations, which employ a variety of approaches and which investigate various cognitive and semantic factors that may influence the development of religious thinking in children, are presented. The investigations that are reported involved individual interviews with 440 children, in the age range from 6 to 11 years. A variety of experimental techniques were employed, including those investigating the children's understanding of various biblical parables, their understanding of the meaning of words used in religious discourse, their conception of historical time and ability to sequentially order events in time, and the way that these factors affected their understanding of religious ideas. The results of the investigations are discussed in terms of the variety of aspects, which they reveal, relating to the development of religious thinking in children. It is argued that this evidence does not support the idea of the development of religious thinking being a unidimensional stage related process; however, the evidence collected from these studies is insufficient to form the basis of an alternative model. It is argued that future studies that follow this approach will be necessary if a satisfactory theory is to be constructed. The educational implications of these findings are discussed and it is argued that certain curriculum changes in the area of religious education may have been made on the basis of insufficient evidence and inadequate theories. http://hdl.handle.net/10023/2758 Abstract: The mainstream of binocular vision research has long been focused on understanding how binocular disparity is used for depth perception. In recent years, researchers have begun to explore how monocular regions in binocularly viewed scenes contribute to our perception of the three-dimensional world. Here we review the field as it currently stands, with a focus on understanding the extent to which the role of monocular regions in depth perception can be understood using extant theories of binocular vision. 2009-11-10T00:00:00Z Harris, Julie Wilcox, LM The mainstream of binocular vision research has long been focused on understanding how binocular disparity is used for depth perception. In recent years, researchers have begun to explore how monocular regions in binocularly viewed scenes contribute to our perception of the three-dimensional world. Here we review the field as it currently stands, with a focus on understanding the extent to which the role of monocular regions in depth perception can be understood using extant theories of binocular vision. http://hdl.handle.net/10023/2757 Abstract: Induced motion, the apparent motion of an object when a nearby object moves, has been shown to occur in a variety of different conditions, including motion in depth. Here we explore whether similar patterns of induced motion result from induction in a lateral direction (frontoparallel motion) or induction in depth. We measured the magnitude of induced motion in a stationary target for: (a) binocularly viewed lateral motion of a pair of inducers, where the angular motion is in the same direction for the two eyes, and (b) binocularly viewed motion in depth of inducers, where the angular motions in the two eyes are opposite to each other, but the same magnitude as for the lateral motion. We found that induced motion is of similar magnitude for the two viewing conditions. This suggests a common mechanism for motion induction by both lateral motion and motion in depth, and is consistent with the idea that the visual signals responsible for induced motion are established before angular information is scaled to obtain metric motion in depth. 2008-02-01T00:00:00Z Harris, Julie German, KJ Induced motion, the apparent motion of an object when a nearby object moves, has been shown to occur in a variety of different conditions, including motion in depth. Here we explore whether similar patterns of induced motion result from induction in a lateral direction (frontoparallel motion) or induction in depth. We measured the magnitude of induced motion in a stationary target for: (a) binocularly viewed lateral motion of a pair of inducers, where the angular motion is in the same direction for the two eyes, and (b) binocularly viewed motion in depth of inducers, where the angular motions in the two eyes are opposite to each other, but the same magnitude as for the lateral motion. We found that induced motion is of similar magnitude for the two viewing conditions. This suggests a common mechanism for motion induction by both lateral motion and motion in depth, and is consistent with the idea that the visual signals responsible for induced motion are established before angular information is scaled to obtain metric motion in depth. http://hdl.handle.net/10023/2749 Abstract: Given an estimate of the binocular disparity between a pair of points and an estimate of the viewing distance, or knowledge of eye position, it should be possible to obtain an estimate of their depth separation. Here we show that, when points are arranged in different vertical geometric configurations across two intervals, many observers find this task difficult. Those who can do the task tend to perceive the depth interval in one configuration as very different from depth in the other configuration. We explore two plausible explanations for this effect. The first is the tilt of the empirical vertical horopter: Points perceived along an apparently vertical line correspond to a physical line of points tilted backwards in space. Second, the eyes can rotate in response to a particular stimulus. Without compensation for this rotation, biases in depth perception would result. We measured cyclovergence indirectly, using a standard psychophysical task, while observers viewed our depth configuration. Biases predicted from error due either to cyclovergence or to the tilted vertical horopter were not consistent with the depth configuration results. Our data suggest that, even for the simplest scenes, we do not have ready access to metric depth from binocular disparity. 2012-01-01T00:00:00Z Harris, Julie Chopin, Adrien Zeiner, Katharina Maria Hibbard, Paul Barry Given an estimate of the binocular disparity between a pair of points and an estimate of the viewing distance, or knowledge of eye position, it should be possible to obtain an estimate of their depth separation. Here we show that, when points are arranged in different vertical geometric configurations across two intervals, many observers find this task difficult. Those who can do the task tend to perceive the depth interval in one configuration as very different from depth in the other configuration. We explore two plausible explanations for this effect. The first is the tilt of the empirical vertical horopter: Points perceived along an apparently vertical line correspond to a physical line of points tilted backwards in space. Second, the eyes can rotate in response to a particular stimulus. Without compensation for this rotation, biases in depth perception would result. We measured cyclovergence indirectly, using a standard psychophysical task, while observers viewed our depth configuration. Biases predicted from error due either to cyclovergence or to the tilted vertical horopter were not consistent with the depth configuration results. Our data suggest that, even for the simplest scenes, we do not have ready access to metric depth from binocular disparity. http://hdl.handle.net/10023/2746 Abstract: There are two ways to detect a displacement in stereoscopic depth, namely by monitoring the change in disparity over time (CDOT) or by monitoring the inter-ocular velocity difference (IOVD). Though previous studies have attempted to understand which cue is most significant for the visual system, none have designed stimuli that provide a comparison in terms of relative efficiency between them. Here we used two-frame motion and random dot noise to deliver equivalent strengths of CDOT and IOVD information to the visual system. Using three kinds of random dot stimuli, we were able to isolate CDOT or IOVD or deliver both simultaneously. The proportion of dots delivering CDOT or IOVD signals could be varied, and we defined discrimination threshold as the proportion needed to detect the direction of displacement (towards or away)1. Thresholds were similar for stimuli containing CDOT only, and containing both CDOT and IOVD, but only one participant was able to consistently perceive the displacement for stimuli containing only IOVD. We also investigated the effect of disparity pedestals on discrimination. Performance was best when the displacement crossed the reference plane, but was not significantly different for stimuli containing CDOT only, or containing both CDOT and IOVD. When stimuli are specifically designed to provide equivalent two-frame motion or disparity-change, few participants can reliably detect displacement when IOVD is the only cue. This challenges the notion that IOVD is involved in the discrimination of direction of displacement in two-frame motion displays. 2010-01-01T00:00:00Z Nefs, Harold Harris, Julie There are two ways to detect a displacement in stereoscopic depth, namely by monitoring the change in disparity over time (CDOT) or by monitoring the inter-ocular velocity difference (IOVD). Though previous studies have attempted to understand which cue is most significant for the visual system, none have designed stimuli that provide a comparison in terms of relative efficiency between them. Here we used two-frame motion and random dot noise to deliver equivalent strengths of CDOT and IOVD information to the visual system. Using three kinds of random dot stimuli, we were able to isolate CDOT or IOVD or deliver both simultaneously. The proportion of dots delivering CDOT or IOVD signals could be varied, and we defined discrimination threshold as the proportion needed to detect the direction of displacement (towards or away)1. Thresholds were similar for stimuli containing CDOT only, and containing both CDOT and IOVD, but only one participant was able to consistently perceive the displacement for stimuli containing only IOVD. We also investigated the effect of disparity pedestals on discrimination. Performance was best when the displacement crossed the reference plane, but was not significantly different for stimuli containing CDOT only, or containing both CDOT and IOVD. When stimuli are specifically designed to provide equivalent two-frame motion or disparity-change, few participants can reliably detect displacement when IOVD is the only cue. This challenges the notion that IOVD is involved in the discrimination of direction of displacement in two-frame motion displays. http://hdl.handle.net/10023/2730 Abstract: This thesis is a reconnaissance of the behavioural ecology of domestic cats. The principal subjects were two groups of farm cats. There was also a group of captive cats and a house cat. The study differs from all previous ones in that the cats were tame and therefore could be shadowed and observed for long periods at all hours. It deals with (1) activity patterns and activity budget, (2) use of space and social behaviour, (3) scent communication, (4) foraging and (5) population dynamics. 1984-01-01T00:00:00Z Panaman, Roger This thesis is a reconnaissance of the behavioural ecology of domestic cats. The principal subjects were two groups of farm cats. There was also a group of captive cats and a house cat. The study differs from all previous ones in that the cats were tame and therefore could be shadowed and observed for long periods at all hours. It deals with (1) activity patterns and activity budget, (2) use of space and social behaviour, (3) scent communication, (4) foraging and (5) population dynamics. http://hdl.handle.net/10023/2697 Abstract: Finding food in tropical forests poses a potentially major problem for chimpanzees, whose ranging is thought primarily to be directed at locating suitable food resources: (1) chimpanzees are frugivorous, large bodied and live in large home ranges; (2) they lack specialised sensory or locomotor abilities, and terrestrial travel is known to be costly; but (3) fruits are randomly distributed in space and time. Evidence from studies of captive individuals suggests chimpanzees are capable of remembering the locations of out of sight resources and can compute least distance routes to these resources, but whether this ability translates to the natural foraging behaviour of wild chimpanzees has never been investigated. My observational study was designed to assess how the chimpanzees (Pan troglodytes schweinfurthii) of Budongo Forest, Uganda, locate these patchy resources. I mapped the routes of 14 focal individuals over a 12-month period. I considered how these foraging routes were structured by breaking the path into segments of travel between resources. Consecutive segments of travel between resources were found not to be independent, but assembled into "super-segments" that take in a number of resources along one trajectory. These super-segments are not necessarily directed towards feeding resources, however: travel is not always food directed. Comparisons of actual chimpanzee routes with randomly generated simulations suggest most individuals do not attempt to minimise their travel distances. There is evidence to suggest energetically stressed individuals can remember the locations of recently visited food resources and return to these patches in order to minimise travel distances when necessary, but overall, food is not difficult to find for this community of chimpanzees. I propose this is because males defend a territory with super-abundant food resources, meaning availability is not a limiting factor of foraging. Male chimpanzees can be characterised as convenience feeders, taking food whilst satisfying other, social needs. 2005-01-01T00:00:00Z Bates, Lucy Finding food in tropical forests poses a potentially major problem for chimpanzees, whose ranging is thought primarily to be directed at locating suitable food resources: (1) chimpanzees are frugivorous, large bodied and live in large home ranges; (2) they lack specialised sensory or locomotor abilities, and terrestrial travel is known to be costly; but (3) fruits are randomly distributed in space and time. Evidence from studies of captive individuals suggests chimpanzees are capable of remembering the locations of out of sight resources and can compute least distance routes to these resources, but whether this ability translates to the natural foraging behaviour of wild chimpanzees has never been investigated. My observational study was designed to assess how the chimpanzees (Pan troglodytes schweinfurthii) of Budongo Forest, Uganda, locate these patchy resources. I mapped the routes of 14 focal individuals over a 12-month period. I considered how these foraging routes were structured by breaking the path into segments of travel between resources. Consecutive segments of travel between resources were found not to be independent, but assembled into "super-segments" that take in a number of resources along one trajectory. These super-segments are not necessarily directed towards feeding resources, however: travel is not always food directed. Comparisons of actual chimpanzee routes with randomly generated simulations suggest most individuals do not attempt to minimise their travel distances. There is evidence to suggest energetically stressed individuals can remember the locations of recently visited food resources and return to these patches in order to minimise travel distances when necessary, but overall, food is not difficult to find for this community of chimpanzees. I propose this is because males defend a territory with super-abundant food resources, meaning availability is not a limiting factor of foraging. Male chimpanzees can be characterised as convenience feeders, taking food whilst satisfying other, social needs. http://hdl.handle.net/10023/2657 Abstract: Few studies have examined depression in children from an Information Processing (IP) perspective. In this thesis a number of domains of IP (known to be associated with adult depression)are examined in children and adolescents, in particular, autobiographical memory specificity in both clinical and non-clinical samples. Foremost, overgeneral memory (OGM) was found for the first time, to be characteristic of dysphoric (Study 1) and clinically depressed children (Study 2). Similarity in the extent of the OGM bias in depressed and dysphoric children was observed. OGM was also comparable across child, adolescent and adult depressed groups (Study 2). Second, OGM predicted depressive symptoms in children during a stressful life event, in the first longitudinal diathesis-stress investigation of OGM to date (Study 3). OGM was also linked for the first time to an overgeneral thinking style and to a depressive attributional style (Study 3) thereby offering possible mechanistic insight in OGM. Third, in support of Williams' (1996) developmental origins hypothesis, OGM was also demonstrated in children in residential care who had suffered significant independently verified negative life events (Study 5). OGM in these youth was positively correlated with deficits in social problem solving and facial-affect identification, in part contextualizing OGM in children alongside depresso-typical biases. Performance on the AMT also varied as a function of severity of abuse with more abused children demonstrating less OGM -a recency memorial coping strategy is proposed to account for this effect. Fourth, a new measure of EF was introduced and highlights the importance of encoding preferences in explaining 0GM (Studies I& 5). Finally, considerable attention is paid to the pattern of valence results across studies. It is noted that effects most often lie with biases in the processing of positive information and that future studies may benefit from a concentration on this aspect of depressogenic bias utilizing a developmental perspective. Several key theoretical and practical implications are carefully discussed. 2006-01-01T00:00:00Z Drummond, Lyndsey Elizabeth Few studies have examined depression in children from an Information Processing (IP) perspective. In this thesis a number of domains of IP (known to be associated with adult depression)are examined in children and adolescents, in particular, autobiographical memory specificity in both clinical and non-clinical samples. Foremost, overgeneral memory (OGM) was found for the first time, to be characteristic of dysphoric (Study 1) and clinically depressed children (Study 2). Similarity in the extent of the OGM bias in depressed and dysphoric children was observed. OGM was also comparable across child, adolescent and adult depressed groups (Study 2). Second, OGM predicted depressive symptoms in children during a stressful life event, in the first longitudinal diathesis-stress investigation of OGM to date (Study 3). OGM was also linked for the first time to an overgeneral thinking style and to a depressive attributional style (Study 3) thereby offering possible mechanistic insight in OGM. Third, in support of Williams' (1996) developmental origins hypothesis, OGM was also demonstrated in children in residential care who had suffered significant independently verified negative life events (Study 5). OGM in these youth was positively correlated with deficits in social problem solving and facial-affect identification, in part contextualizing OGM in children alongside depresso-typical biases. Performance on the AMT also varied as a function of severity of abuse with more abused children demonstrating less OGM -a recency memorial coping strategy is proposed to account for this effect. Fourth, a new measure of EF was introduced and highlights the importance of encoding preferences in explaining 0GM (Studies I& 5). Finally, considerable attention is paid to the pattern of valence results across studies. It is noted that effects most often lie with biases in the processing of positive information and that future studies may benefit from a concentration on this aspect of depressogenic bias utilizing a developmental perspective. Several key theoretical and practical implications are carefully discussed. http://hdl.handle.net/10023/2656 Abstract: This thesis takes an evolutionary perspective on human psychology. To the extent that inherited tendencies shape behaviour, their design will be fitted to the social environments prevailing as Homo sapiens evolved, in foraging groups, the nearest modem equivalent being hunter-gatherers. From ethnographies of hunter-gatherers, food-sharing and counterdominance were identified as universal. Food-sharing was more thorough than is explicable purely by kinship or reciprocation; one functional effect was to even out the supply of valuable high-variance food. In contrast with the social systems of the other great apes, counter-dominance spread influence widely, preventing the emergence of dominant individuals who could obtain resources disproportionately. Potential paths for the evolution of egalitarian tendencies are discussed. Two falsifiable hypotheses were generated from this perspective. First, sharing will facilitate risk-taking. The predicted effect was confirmed at high risk levels, similar to those faced by hunters. Given that during evolution risk was reduced primarily by social means, social as well as rational factors are treated by the evolved brain as relevant to risky decisions. It is argued that this result may suggest a new perspective on the Group Polarisation experiments. The second hypothesis tested was that an egalitarian environment will produce beneficial effects on individual and social behaviour. The data collected were consistent with the hypothesis: a comparison between three Italian towns showed that measures of health (including cardiovascular mortality), education, social involvement, crime and social perceptions were significantly more positive where co-operatives employed a larger percentage of the population. The evolutionary perspective showed its value as a means of generating novel testable hypotheses. 2000-01-01T00:00:00Z Erdal, David Edward This thesis takes an evolutionary perspective on human psychology. To the extent that inherited tendencies shape behaviour, their design will be fitted to the social environments prevailing as Homo sapiens evolved, in foraging groups, the nearest modem equivalent being hunter-gatherers. From ethnographies of hunter-gatherers, food-sharing and counterdominance were identified as universal. Food-sharing was more thorough than is explicable purely by kinship or reciprocation; one functional effect was to even out the supply of valuable high-variance food. In contrast with the social systems of the other great apes, counter-dominance spread influence widely, preventing the emergence of dominant individuals who could obtain resources disproportionately. Potential paths for the evolution of egalitarian tendencies are discussed. Two falsifiable hypotheses were generated from this perspective. First, sharing will facilitate risk-taking. The predicted effect was confirmed at high risk levels, similar to those faced by hunters. Given that during evolution risk was reduced primarily by social means, social as well as rational factors are treated by the evolved brain as relevant to risky decisions. It is argued that this result may suggest a new perspective on the Group Polarisation experiments. The second hypothesis tested was that an egalitarian environment will produce beneficial effects on individual and social behaviour. The data collected were consistent with the hypothesis: a comparison between three Italian towns showed that measures of health (including cardiovascular mortality), education, social involvement, crime and social perceptions were significantly more positive where co-operatives employed a larger percentage of the population. The evolutionary perspective showed its value as a means of generating novel testable hypotheses. http://hdl.handle.net/10023/2654 Abstract: This work examined four issues, in relation to both the experience of depression, and vulnerability to depression. There were four empirical studies, each with two parts. The first study examined the role of cognitions, such as overgeneralizations (Beck, 1963; Beck et al, 1979), and causal attributions (Abramson et al, 1978; Alloy et al, 1988). Their role as symptoms of depression, and as possible vulnerability factors, independent of current mood, was examined. In the first part of the study, clinically depressed patients, recovered subjects, and community control subjects were interviewed and given questionnaires. In the second part of the study a larger sample of students, some of whom became mildly depressed on beginning university filled in questionnaires at the start of term and again five weeks later. The same subject groups were the basis for the study on social factors, and the study on life events. The fourth study was also in two parts. A different sample of students were the subjects for the first part, and the same clinical and control groups participated in the second part. Factors found to be associated with the state of depression were: Internal, stable and global attributions for the causes of bad events, negative view of future outcomes, and negative view of self; social skill deficits and lack of social support; recent difficult life events. One factor failed to show any strong association with the depressed state – unrealistic goals. Factors associated with vulnerability to depression: Negative evaluations of future outcomes, and of self, unrealistic goals and, surprisingly, lower-than-normal goals; deficits in social skill (especially low self-confidence in social settings) and lack of social support; history-of difficult life events. Factors which failed to show association with vulnerability to depression: Causal-attributions for events; adverse reaction to depression itself. Deficits in social skill were associated with lack of social support. Depression proneness itself appeared to be a risk factor for negative life events. 1991-01-01T00:00:00Z Holttum, Susan This work examined four issues, in relation to both the experience of depression, and vulnerability to depression. There were four empirical studies, each with two parts. The first study examined the role of cognitions, such as overgeneralizations (Beck, 1963; Beck et al, 1979), and causal attributions (Abramson et al, 1978; Alloy et al, 1988). Their role as symptoms of depression, and as possible vulnerability factors, independent of current mood, was examined. In the first part of the study, clinically depressed patients, recovered subjects, and community control subjects were interviewed and given questionnaires. In the second part of the study a larger sample of students, some of whom became mildly depressed on beginning university filled in questionnaires at the start of term and again five weeks later. The same subject groups were the basis for the study on social factors, and the study on life events. The fourth study was also in two parts. A different sample of students were the subjects for the first part, and the same clinical and control groups participated in the second part. Factors found to be associated with the state of depression were: Internal, stable and global attributions for the causes of bad events, negative view of future outcomes, and negative view of self; social skill deficits and lack of social support; recent difficult life events. One factor failed to show any strong association with the depressed state – unrealistic goals. Factors associated with vulnerability to depression: Negative evaluations of future outcomes, and of self, unrealistic goals and, surprisingly, lower-than-normal goals; deficits in social skill (especially low self-confidence in social settings) and lack of social support; history-of difficult life events. Factors which failed to show association with vulnerability to depression: Causal-attributions for events; adverse reaction to depression itself. Deficits in social skill were associated with lack of social support. Depression proneness itself appeared to be a risk factor for negative life events. http://hdl.handle.net/10023/2636 Abstract: The principle objective of this study was to describe and record all the gathering and processing skills of vervet monkeys for a variety of different foods. The study was conducted on two troops of vervet monkeys living in the Palmiet Valley, Natal, South Africa. There was sufficient data to analyze the processing of four foods of differing complexity; termites, leaf shoots, sugarcane and fruit. Milton (1988) proposed that the intellectual difficulties of finding and processing food led to the evolution of intelligence. In the only study of food processing skill, Byrne and Byrne (1993) showed that gorillas use a hierarchical organization perhaps reflecting imitation at the program-level. The question to be asked in this study was, would vervets also organize their processing into a few techniques for specific foods and would it then be possible to identify learning mechanisms used by the monkeys? The current literature suggests that monkeys use simple solutions to their foraging problems, there is no evidence for imitation of feeding skills in monkeys. At the most detailed level of analysis, grip types used in the processing of foods were described. Existing definitions in the literature were not adequate to explain the monkeys' hand use, and new definitions were added. High individual idiosyncrasy was a feature of grip usage across all four foods, although firm conclusions are not possible because of the known effects of sample size. Cluster analysis was considered the most appropriate method to look at individual variation in grip usage. There was an age effect for leaf shoots and sugarcane, with juveniles restricting their usage to the necessary core grips. The hand preferences for individuals across tasks gave no support for the theory of the evolution of laterality presented by MacNeilage et al. (1987). There was a low degree of individual preference for five out of six tasks, with only termite feeding showing a hand preference. There was some evidence for a right hand reaching, left hand manipulation preference, opposite to MacNeilage's prediction. There was an age effect in direction and strength for two tasks, adults having a stronger left hand preference in contrast to a weaker right hand preference in juveniles for leaf shoots and large fruit. Matrices of the transitional probabilities between two elements, were used to construct the common pathways of processing skill for each individual. Flow diagrams were then created to represent the minimal decision processes used by the monkeys. The diagrams were used to compare individuals' choice of pathways. Cluster analysis was used to analyze pathway choice in detail; none of a variety of independent variables could explain the high individual variation. Whether whole foods or just parts of foods were eaten did explain some of the variance for sugarcane and fruit. The most parsimonious explanation is that social enhancement resulting in trial and error learning best described individuals' acquisition of processing skill, although a number of other factors may explain the observed results. 1997-01-01T00:00:00Z Harrison, Kathryn The principle objective of this study was to describe and record all the gathering and processing skills of vervet monkeys for a variety of different foods. The study was conducted on two troops of vervet monkeys living in the Palmiet Valley, Natal, South Africa. There was sufficient data to analyze the processing of four foods of differing complexity; termites, leaf shoots, sugarcane and fruit. Milton (1988) proposed that the intellectual difficulties of finding and processing food led to the evolution of intelligence. In the only study of food processing skill, Byrne and Byrne (1993) showed that gorillas use a hierarchical organization perhaps reflecting imitation at the program-level. The question to be asked in this study was, would vervets also organize their processing into a few techniques for specific foods and would it then be possible to identify learning mechanisms used by the monkeys? The current literature suggests that monkeys use simple solutions to their foraging problems, there is no evidence for imitation of feeding skills in monkeys. At the most detailed level of analysis, grip types used in the processing of foods were described. Existing definitions in the literature were not adequate to explain the monkeys' hand use, and new definitions were added. High individual idiosyncrasy was a feature of grip usage across all four foods, although firm conclusions are not possible because of the known effects of sample size. Cluster analysis was considered the most appropriate method to look at individual variation in grip usage. There was an age effect for leaf shoots and sugarcane, with juveniles restricting their usage to the necessary core grips. The hand preferences for individuals across tasks gave no support for the theory of the evolution of laterality presented by MacNeilage et al. (1987). There was a low degree of individual preference for five out of six tasks, with only termite feeding showing a hand preference. There was some evidence for a right hand reaching, left hand manipulation preference, opposite to MacNeilage's prediction. There was an age effect in direction and strength for two tasks, adults having a stronger left hand preference in contrast to a weaker right hand preference in juveniles for leaf shoots and large fruit. Matrices of the transitional probabilities between two elements, were used to construct the common pathways of processing skill for each individual. Flow diagrams were then created to represent the minimal decision processes used by the monkeys. The diagrams were used to compare individuals' choice of pathways. Cluster analysis was used to analyze pathway choice in detail; none of a variety of independent variables could explain the high individual variation. Whether whole foods or just parts of foods were eaten did explain some of the variance for sugarcane and fruit. The most parsimonious explanation is that social enhancement resulting in trial and error learning best described individuals' acquisition of processing skill, although a number of other factors may explain the observed results. http://hdl.handle.net/10023/2575 Abstract: Titi monkeys have long been known for their complex vocal behaviour with numerous high- and low-pitched calls, which can be uttered singly or combined in more complex structures. However, up to date very little is known concerning the function, meaning and context-specific use of these vocal utterances, and virtually nothing is known about their vocalisations in the predation context. This thesis presents a detailed description of the form and function of the anti-predator behaviour of one species of titi monkeys, the black-fronted titi monkey (Callicebus nigrifrons), with a specific focus on their alarm call behaviour. A second aim was to determine the exact mechanisms of alarm calling behaviour, with an emphasis on production and comprehension. Data were collected from several habituated groups in the Caraça Reserve, Minas Gerais, Brazil. Results showed that, when detecting predator species, C nigrifrons produce sequences that initially contain two types of brief, high-pitched calls with distinct frequency contours. Further evidence suggested that some of these sequences are meaningful to conspecific receivers, by indicating the general predator class and location of threat. There were also indications that, within the terrestrial threats, additional information may be encoded by acoustic and compositional differences. Analyses of call order and number of calls per sequence suggested that callers may be able to convey information on both predator type and location. The black-fronted titi monkeys’ vocal system thus provides a further example of zoo-syntax, in which acoustically fixed units of a vocal repertoire are combined into higher order sequences that are meaningful to recipients. According to current definitions, this type of calling behaviour qualifies as functionally referential, by indicating general predator class, terrestrial predator type and location. As such, this is the first empirical demonstration of a sequence-based alarm call system that conveys information on both predator category and location. 2012-06-01T00:00:00Z Cäsar, Cristiane Titi monkeys have long been known for their complex vocal behaviour with numerous high- and low-pitched calls, which can be uttered singly or combined in more complex structures. However, up to date very little is known concerning the function, meaning and context-specific use of these vocal utterances, and virtually nothing is known about their vocalisations in the predation context. This thesis presents a detailed description of the form and function of the anti-predator behaviour of one species of titi monkeys, the black-fronted titi monkey (Callicebus nigrifrons), with a specific focus on their alarm call behaviour. A second aim was to determine the exact mechanisms of alarm calling behaviour, with an emphasis on production and comprehension. Data were collected from several habituated groups in the Caraça Reserve, Minas Gerais, Brazil. Results showed that, when detecting predator species, C nigrifrons produce sequences that initially contain two types of brief, high-pitched calls with distinct frequency contours. Further evidence suggested that some of these sequences are meaningful to conspecific receivers, by indicating the general predator class and location of threat. There were also indications that, within the terrestrial threats, additional information may be encoded by acoustic and compositional differences. Analyses of call order and number of calls per sequence suggested that callers may be able to convey information on both predator type and location. The black-fronted titi monkeys’ vocal system thus provides a further example of zoo-syntax, in which acoustically fixed units of a vocal repertoire are combined into higher order sequences that are meaningful to recipients. According to current definitions, this type of calling behaviour qualifies as functionally referential, by indicating general predator class, terrestrial predator type and location. As such, this is the first empirical demonstration of a sequence-based alarm call system that conveys information on both predator category and location. http://hdl.handle.net/10023/2560 Abstract: Recent years have seen increasing encouragement by research institutions and funding bodies for scientists to actively engage with the public, who ultimately finance their work. Animal behaviour as a discipline possesses several features, including its inherent accessibility and appeal to the public, that may help it occupy a particularly successful niche within these developments. It has also established a repertoire of quantitative behavioural methodologies that can be used to document the public's responses to engagement initiatives. This kind of assessment is becoming increasingly important considering the enormous effort now being put into public engagement projects, whose effects are more often assumed than demonstrated. Here we report our first attempts to quantify relevant aspects of the behaviour of a sample of the hundreds of thousands of visitors who pass through the ‘Living Links to Human Evolution Research Centre’ in Edinburgh Zoo. This University research centre actively encourages the public to view ongoing primate research and associated science engagement activities. Focal follows of visitors and scan sampling showed substantial ‘dwell times’ in the Centre by common zoo standards and the addition of new engagement elements in a second year was accompanied by significantly increased overall dwell times, tripling for the most committed two thirds of visitors. Larger groups of visitors were found to spend more time in the Centre than smaller ones. Viewing live, active science was the most effective activity, shown to be enhanced by novel presentations of carefully constructed explanatory materials. The findings emphasise the importance and potential of zoos as public engagement centres for the biological sciences. 2012-04-04T00:00:00Z Bowler, Mark Timothy Buchanan-Smith, Hannah M Whiten, Andrew Recent years have seen increasing encouragement by research institutions and funding bodies for scientists to actively engage with the public, who ultimately finance their work. Animal behaviour as a discipline possesses several features, including its inherent accessibility and appeal to the public, that may help it occupy a particularly successful niche within these developments. It has also established a repertoire of quantitative behavioural methodologies that can be used to document the public's responses to engagement initiatives. This kind of assessment is becoming increasingly important considering the enormous effort now being put into public engagement projects, whose effects are more often assumed than demonstrated. Here we report our first attempts to quantify relevant aspects of the behaviour of a sample of the hundreds of thousands of visitors who pass through the ‘Living Links to Human Evolution Research Centre’ in Edinburgh Zoo. This University research centre actively encourages the public to view ongoing primate research and associated science engagement activities. Focal follows of visitors and scan sampling showed substantial ‘dwell times’ in the Centre by common zoo standards and the addition of new engagement elements in a second year was accompanied by significantly increased overall dwell times, tripling for the most committed two thirds of visitors. Larger groups of visitors were found to spend more time in the Centre than smaller ones. Viewing live, active science was the most effective activity, shown to be enhanced by novel presentations of carefully constructed explanatory materials. The findings emphasise the importance and potential of zoos as public engagement centres for the biological sciences. http://hdl.handle.net/10023/2555 Abstract: Conformity is thought to be an important force in cultural evolution because it has the potential to stabilize cooperation in large groups, potentiate group selection and thus explain uniquely human behaviors. However, the effects of such conformity on cultural and biological evolution will depend much on the way individuals are influenced by the frequency of alternative behavioral options witnessed. Theoretical modeling has suggested that only what we refer to as ‘hyper-conformity’, an exaggerated tendency to perform the most frequent behavior witnessed in other individuals, is able to increase within-group homogeneity and between-group diversity, for instance. Empirically however, few experiments have addressed how the frequency of behavior witnessed affects behavior. Accordingly we performed an experiment to test for the presence of conformity in a natural situation with humans. Visitors to a Zoo exhibit were invited to write or draw answers to questions on A5 cards and potentially win a small prize. We manipulated the proportion of existing writings versus drawings visible to visitors and measured the proportion of written cards submitted. We found a strong and significant effect of the proportion of text displayed on the proportion of text in the answers, thus demonstrating social learning. We show that this effect is approximately linear, with potentially a small, weak-conformist component but no hyper-conformist one. The present experiment therefore provides evidence for linear conformity in humans in a very natural context. 2012-02-20T00:00:00Z Claidiere, Nicolas Bowler, Mark Timothy Whiten, Andrew Conformity is thought to be an important force in cultural evolution because it has the potential to stabilize cooperation in large groups, potentiate group selection and thus explain uniquely human behaviors. However, the effects of such conformity on cultural and biological evolution will depend much on the way individuals are influenced by the frequency of alternative behavioral options witnessed. Theoretical modeling has suggested that only what we refer to as ‘hyper-conformity’, an exaggerated tendency to perform the most frequent behavior witnessed in other individuals, is able to increase within-group homogeneity and between-group diversity, for instance. Empirically however, few experiments have addressed how the frequency of behavior witnessed affects behavior. Accordingly we performed an experiment to test for the presence of conformity in a natural situation with humans. Visitors to a Zoo exhibit were invited to write or draw answers to questions on A5 cards and potentially win a small prize. We manipulated the proportion of existing writings versus drawings visible to visitors and measured the proportion of written cards submitted. We found a strong and significant effect of the proportion of text displayed on the proportion of text in the answers, thus demonstrating social learning. We show that this effect is approximately linear, with potentially a small, weak-conformist component but no hyper-conformist one. The present experiment therefore provides evidence for linear conformity in humans in a very natural context. http://hdl.handle.net/10023/2550 Abstract: Human adolescents exhibit higher levels of sensation seeking behaviour than younger or older individuals, and sensation seeking is higher in males than females from adolescence onwards. Data suggest that changes in gonadal hormone levels during adolescence and differences in the dopamine neurotransmitter system are the bases for why some people exhibit sensation seeking behaviour while others do not. However, causal relationships between physiology and behaviour have been difficult to establish in humans. In order to explore the physiological influences on novelty-seeking behaviour, we looked at response to novelty in a laboratory rodent. This research examined responses to novelty in the conditioned place preference (CPP) task and the novel object recognition (NOR) task in Lister-hooded rats, and assessed the benefits and limitations of each methodology. While the CPP task was not found to provide a reliable measure of response to novelty, the NOR task was more successful. In order to understand the ontogeny of sex differences in novelty responses, both males and females were tested from adolescence through to adulthood. While no sex difference was found in adults in the NOR test, mid-adolescent males exhibited higher novelty preference behaviour than either younger or older males, or females at each stage of development. Since gonadal hormones levels rise during adolescence, a pharmacological agent (a gonadotrophin-releasing hormone antagonist) was used to suppress gonadal hormone levels from early adolescence before again examining responses on the NOR test at mid-adolescence. Gonadal hormone suppression from early adolescence onwards eliminated the sex difference in the NOR test at mid-adolescence by reducing the male response to novelty, while no difference was measured in the female animals. These findings suggest that gonadal hormones play a significant role in the development of response to novelty, especially in males, and the implications for our understanding of human sensation-seeking behaviour are discussed. Description: Electronic version excludes material for which permission has not been granted by the rights holder 2012-06-19T00:00:00Z Cyrenne, De-Laine Human adolescents exhibit higher levels of sensation seeking behaviour than younger or older individuals, and sensation seeking is higher in males than females from adolescence onwards. Data suggest that changes in gonadal hormone levels during adolescence and differences in the dopamine neurotransmitter system are the bases for why some people exhibit sensation seeking behaviour while others do not. However, causal relationships between physiology and behaviour have been difficult to establish in humans. In order to explore the physiological influences on novelty-seeking behaviour, we looked at response to novelty in a laboratory rodent. This research examined responses to novelty in the conditioned place preference (CPP) task and the novel object recognition (NOR) task in Lister-hooded rats, and assessed the benefits and limitations of each methodology. While the CPP task was not found to provide a reliable measure of response to novelty, the NOR task was more successful. In order to understand the ontogeny of sex differences in novelty responses, both males and females were tested from adolescence through to adulthood. While no sex difference was found in adults in the NOR test, mid-adolescent males exhibited higher novelty preference behaviour than either younger or older males, or females at each stage of development. Since gonadal hormones levels rise during adolescence, a pharmacological agent (a gonadotrophin-releasing hormone antagonist) was used to suppress gonadal hormone levels from early adolescence before again examining responses on the NOR test at mid-adolescence. Gonadal hormone suppression from early adolescence onwards eliminated the sex difference in the NOR test at mid-adolescence by reducing the male response to novelty, while no difference was measured in the female animals. These findings suggest that gonadal hormones play a significant role in the development of response to novelty, especially in males, and the implications for our understanding of human sensation-seeking behaviour are discussed. http://hdl.handle.net/10023/2446 Abstract: The adaptive function of copulation calls in female primates has been debated for years. One influential idea is that copulation calls are a sexually selected trait, which enables females to advertise their receptive state to males. Male-male competition ensues and females benefit by getting better mating partners and higher quality offspring. We analysed the copulation calling behaviour of wild female chimpanzees (Pan troglodytes schweinfurthii) at Budongo Forest, Uganda, but found no support for the male-male competition hypothesis. Hormone analysis showed that the calling behaviour of copulating females was unrelated to their fertile period and likelihood of conception. Instead, females called significantly more while with high-ranking males, but suppressed their calls if high-ranking females were nearby. Copulation calling may therefore be one potential strategy employed by female chimpanzees to advertise receptivity to high-ranked males, confuse paternity and secure future support from these socially important individuals. Competition between females can be dangerously high in wild chimpanzees, and our results indicate that females use their copulation calls strategically to minimise the risks associated with such competition. 2008-06-18T00:00:00Z Townsend, Simon W. Deschner, Tobias Zuberbuehler, Klaus The adaptive function of copulation calls in female primates has been debated for years. One influential idea is that copulation calls are a sexually selected trait, which enables females to advertise their receptive state to males. Male-male competition ensues and females benefit by getting better mating partners and higher quality offspring. We analysed the copulation calling behaviour of wild female chimpanzees (Pan troglodytes schweinfurthii) at Budongo Forest, Uganda, but found no support for the male-male competition hypothesis. Hormone analysis showed that the calling behaviour of copulating females was unrelated to their fertile period and likelihood of conception. Instead, females called significantly more while with high-ranking males, but suppressed their calls if high-ranking females were nearby. Copulation calling may therefore be one potential strategy employed by female chimpanzees to advertise receptivity to high-ranked males, confuse paternity and secure future support from these socially important individuals. Competition between females can be dangerously high in wild chimpanzees, and our results indicate that females use their copulation calls strategically to minimise the risks associated with such competition. http://hdl.handle.net/10023/2320 Abstract: Background: It is well established that nucleus basalis magnocellularis (NbM) lesions impair performance on tests of sustained attention. Previous work from this laboratory has also demonstrated that pedunculopontine tegmental nucleus (PPTg) lesioned rats make more omissions on a test of sustained attention, suggesting that it might also play a role in mediating this function. However, the results of the PPTg study were open to alternative interpretation. We aimed to resolve this by conducting a detailed analysis of the effects of damage to each brain region in the same sustained attention task used in our previous work. Rats were trained in the task before surgery and post-surgical testing examined performance in response to unpredictable light signals of 1500 ms and 4000 ms duration. Data for PPTg lesioned rats were compared to control rats, and rats with 192 IgG saporin infusions centred on the NbM. In addition to operant data, video data of rats' performance during the task were also analysed. Results: Both lesion groups omitted trials relative to controls but the effect was milder and transient in NbM rats. The number of omitted trials decreased in all groups when tested using the 4000 ms signal compared to the 1500 ms signal. This confirmed previous findings for PPTg lesioned rats. Detailed analysis revealed that the increase in omissions in PPTg rats was not a consequence of motor impairment. The video data (taken on selected days) showed reduced lever orientation in PPTg lesioned rats, coupled with an increase in unconditioned behaviours such as rearing and sniffing. In contrast NbM rats showed evidence of inadequate lever pressing. Conclusion: The question addressed here is whether the PPTg and NbM both have a role in sustained attention. Rats bearing lesions of either structure showed deficits in the test used. However, we conclude that the most parsimonious explanation for the deficit observed in PPTg rats is inadequate response organization, rather than impairment in sustained attention. Furthermore the impairment observed in NbM lesioned rats included lever pressing difficulties in addition to impaired sustained attention. Unfortunately we could not link these deficits directly to cholinergic neuronal loss. Description: Additional 'open data' files can be found on the publisher's site at http://www.biomedcentral.com/1471-2202/9/16 2008-01-30T00:00:00Z Rostron, Claire L. Farquhar, Morag J. Latimer, Mary P. Winn, Philip Background: It is well established that nucleus basalis magnocellularis (NbM) lesions impair performance on tests of sustained attention. Previous work from this laboratory has also demonstrated that pedunculopontine tegmental nucleus (PPTg) lesioned rats make more omissions on a test of sustained attention, suggesting that it might also play a role in mediating this function. However, the results of the PPTg study were open to alternative interpretation. We aimed to resolve this by conducting a detailed analysis of the effects of damage to each brain region in the same sustained attention task used in our previous work. Rats were trained in the task before surgery and post-surgical testing examined performance in response to unpredictable light signals of 1500 ms and 4000 ms duration. Data for PPTg lesioned rats were compared to control rats, and rats with 192 IgG saporin infusions centred on the NbM. In addition to operant data, video data of rats' performance during the task were also analysed. Results: Both lesion groups omitted trials relative to controls but the effect was milder and transient in NbM rats. The number of omitted trials decreased in all groups when tested using the 4000 ms signal compared to the 1500 ms signal. This confirmed previous findings for PPTg lesioned rats. Detailed analysis revealed that the increase in omissions in PPTg rats was not a consequence of motor impairment. The video data (taken on selected days) showed reduced lever orientation in PPTg lesioned rats, coupled with an increase in unconditioned behaviours such as rearing and sniffing. In contrast NbM rats showed evidence of inadequate lever pressing. Conclusion: The question addressed here is whether the PPTg and NbM both have a role in sustained attention. Rats bearing lesions of either structure showed deficits in the test used. However, we conclude that the most parsimonious explanation for the deficit observed in PPTg rats is inadequate response organization, rather than impairment in sustained attention. Furthermore the impairment observed in NbM lesioned rats included lever pressing difficulties in addition to impaired sustained attention. Unfortunately we could not link these deficits directly to cholinergic neuronal loss. http://hdl.handle.net/10023/2250 Abstract: It is well established that the intracellular accumulation of beta-amyloid is associated with Alzheimer’s disease and that this accumulation is toxic to neurons. The precise mechanism by which this toxicity occurs is not well understood, however, identifying the causes of this toxicity is an essential step in developing treatments for Alzheimer’s disease. One intracellular location where the accumulation of beta-amyloid can have a major effect is within mitochondria has identified mitochondrial proteins that act as binding sites for beta-amyloid and when binding occurs a toxic response results. For one of these identified sites, an enzyme known as ‘ABAD’, we have identified the changes in gene expression in the brain cortex following beta-amyloid accumulation within mitochondria. Specifically, we have identified two proteins that are upregulated in the brains of transgenic animal models for Alzheimer’s disease but also human sufferers. The increased expression of these proteins demonstrates the complex and counter-acting pathways that are activated in Alzheimer’s disease. Previous studies have identified the approximate contact sites between ABAD and beta-amyloid, and based on these observations we have shown that using a modified peptide approach, it is possible to reverse the expression of these two proteins in living transgenic animals and also recover both mitochondrial and behavioural deficits. This indicates that the ABAD-beta-amyloid interaction is potentially an interesting target for therapeutic intervention. To explore this further we used a fluorescing substrate mimic to measure the activity of ABAD within living cells, and in addition we have identified chemical fragments that bind to ABAD, by using a thermal shift assay. Description: This research is supported by Alzheimer's Research UK, the Wellcome Trust and the Biotechnology and Biological Sciences Research Council. 2011-08-01T00:00:00Z Borger, Eva Aitken, Laura Muirhead, Kirsty Elizabeth Adair Allen, Zoe Eleanor Ainge, James Alexander Conway, Stuart Gunn-Moore, Frank J It is well established that the intracellular accumulation of beta-amyloid is associated with Alzheimer’s disease and that this accumulation is toxic to neurons. The precise mechanism by which this toxicity occurs is not well understood, however, identifying the causes of this toxicity is an essential step in developing treatments for Alzheimer’s disease. One intracellular location where the accumulation of beta-amyloid can have a major effect is within mitochondria has identified mitochondrial proteins that act as binding sites for beta-amyloid and when binding occurs a toxic response results. For one of these identified sites, an enzyme known as ‘ABAD’, we have identified the changes in gene expression in the brain cortex following beta-amyloid accumulation within mitochondria. Specifically, we have identified two proteins that are upregulated in the brains of transgenic animal models for Alzheimer’s disease but also human sufferers. The increased expression of these proteins demonstrates the complex and counter-acting pathways that are activated in Alzheimer’s disease. Previous studies have identified the approximate contact sites between ABAD and beta-amyloid, and based on these observations we have shown that using a modified peptide approach, it is possible to reverse the expression of these two proteins in living transgenic animals and also recover both mitochondrial and behavioural deficits. This indicates that the ABAD-beta-amyloid interaction is potentially an interesting target for therapeutic intervention. To explore this further we used a fluorescing substrate mimic to measure the activity of ABAD within living cells, and in addition we have identified chemical fragments that bind to ABAD, by using a thermal shift assay. http://hdl.handle.net/10023/2143 Abstract: Great ape gesture is an elaborate, flexible system of intentional communication. It has been suggested that human language originated in gesture, thus, the gestural communication of great apes is of great interest for questions on the origin of language. To date, systematic studies of great ape gesture have been limited to restricted captive settings, supplemented by the study of a few specific gestures in wild populations. To address questions about gestural communication from an evolutionary perspective it is necessary to extend the systematic study of gesture into a wild ape population. I therefore undertook a 22-month study of gesture in the wild Sonso chimpanzee community in Budongo, Uganda. Sonso chimpanzees employ a large repertoire of species-typical gestures in intentional communication; a proportion of this repertoire appears to be ape-typical, as would be expected with a biologically given trait. Chimpanzees can acquire new behavioural patterns through imitation; however, this apparently does not represent a significant means of acquiring gestures. Gesturing was employed regularly in an intentional manner from the end of the first year, and was used by chimpanzees of all ages to communicate across a range of contexts, including the evolutionarily urgent context of consortship. Immature chimpanzees used a wide range of gestures, which they combined into rapid sequences. With maturity, use of the repertoire was ‘tuned’ to focus on the most effective gestures, which were then used individually. Despite the evidence for referential pointing in captive chimpanzees, there was little evidence for the regular use of it in wild chimpanzees. Gestures were used to communicate a range of imperative requests that regulated social behaviour. Chimpanzee gestures vary from the ambiguous to the highly specific in meaning; and, while gestures were used flexibly, they tended to be associated with a single dominant meaning. 2012-06-21T00:00:00Z Hobaiter, Catherine Great ape gesture is an elaborate, flexible system of intentional communication. It has been suggested that human language originated in gesture, thus, the gestural communication of great apes is of great interest for questions on the origin of language. To date, systematic studies of great ape gesture have been limited to restricted captive settings, supplemented by the study of a few specific gestures in wild populations. To address questions about gestural communication from an evolutionary perspective it is necessary to extend the systematic study of gesture into a wild ape population. I therefore undertook a 22-month study of gesture in the wild Sonso chimpanzee community in Budongo, Uganda. Sonso chimpanzees employ a large repertoire of species-typical gestures in intentional communication; a proportion of this repertoire appears to be ape-typical, as would be expected with a biologically given trait. Chimpanzees can acquire new behavioural patterns through imitation; however, this apparently does not represent a significant means of acquiring gestures. Gesturing was employed regularly in an intentional manner from the end of the first year, and was used by chimpanzees of all ages to communicate across a range of contexts, including the evolutionarily urgent context of consortship. Immature chimpanzees used a wide range of gestures, which they combined into rapid sequences. With maturity, use of the repertoire was ‘tuned’ to focus on the most effective gestures, which were then used individually. Despite the evidence for referential pointing in captive chimpanzees, there was little evidence for the regular use of it in wild chimpanzees. Gestures were used to communicate a range of imperative requests that regulated social behaviour. Chimpanzee gestures vary from the ambiguous to the highly specific in meaning; and, while gestures were used flexibly, they tended to be associated with a single dominant meaning. http://hdl.handle.net/10023/2118 Abstract: Obesity and ageing are both characteristics of the human population that are on the increase across the globe. It has long been established that ageing is the major risk factor for neurodegenerative conditions such as Alzheimer’s disease, and it is becoming increasingly evident that obesity is another such factor. Leptin resistance or insensitivity has been uncovered as a cause of obesity, and in addition the leptin signalling system is less potent in the elderly. Taken together, these findings reveal that this molecule may be a link between neurodegeneration and obesity or ageing. It is now known that leptin has beneficial effects on both the survival and neurophysiology of the neurons that are lost in Alzheimer’s disease suggesting that it may be an important research target in the quest for strategies to prevent, halt or cure this condition. 2011-01-01T00:00:00Z Doherty, Gayle Helane Obesity and ageing are both characteristics of the human population that are on the increase across the globe. It has long been established that ageing is the major risk factor for neurodegenerative conditions such as Alzheimer’s disease, and it is becoming increasingly evident that obesity is another such factor. Leptin resistance or insensitivity has been uncovered as a cause of obesity, and in addition the leptin signalling system is less potent in the elderly. Taken together, these findings reveal that this molecule may be a link between neurodegeneration and obesity or ageing. It is now known that leptin has beneficial effects on both the survival and neurophysiology of the neurons that are lost in Alzheimer’s disease suggesting that it may be an important research target in the quest for strategies to prevent, halt or cure this condition. http://hdl.handle.net/10023/2071 2008-09-01T00:00:00Z O'Connor, Akira http://hdl.handle.net/10023/2021 Abstract: In this article we explore a self-regulatory perspective on the self-evaluative moral emotions, shame and guilt. Broadly conceived, self-regulation distinguishes between two types of motivation: approach/activation and avoidance/inhibition. We use this distinction to conceptually understand the socialization dimensions (parental restrictiveness versus nurturance), associated emotions (anxiety versus empathy), and forms of morality (proscriptive versus prescriptive) that serve as precursors to each self-evaluative moral emotion. We then examine the components of shame and guilt experiences in greater detail and conclude with more general implications of a self-regulatory perspective on moral emotions. 2010-10-01T00:00:00Z Sheikh, Sana Janoff-Bulman, Ronnie In this article we explore a self-regulatory perspective on the self-evaluative moral emotions, shame and guilt. Broadly conceived, self-regulation distinguishes between two types of motivation: approach/activation and avoidance/inhibition. We use this distinction to conceptually understand the socialization dimensions (parental restrictiveness versus nurturance), associated emotions (anxiety versus empathy), and forms of morality (proscriptive versus prescriptive) that serve as precursors to each self-evaluative moral emotion. We then examine the components of shame and guilt experiences in greater detail and conclude with more general implications of a self-regulatory perspective on moral emotions. http://hdl.handle.net/10023/2003 Abstract: To investigate form-related activity inmotion-sensitive cortical areas, we recorded cell responses to animate implied motion in macaque middle temporal (MT) and medial superior temporal (MST) cortex and investigated these areas using fMRI in humans. In the single-cell studies, we compared responses with static images of human or monkey figures walking or running left or right with responses to the same human and monkey figures standing or sitting still. We also investigated whether the view of the animate figure (facing left or right) that elicited the highest response was correlated with the preferred direction for moving random dot patterns. First, figures were presented inside the cell's receptive field. Subsequently, figures were presented at the fovea while a dynamic noise pattern was presented at the cell's receptive field location. The results show that MT neurons did not discriminate between figures on the basis of the implied motion content. Instead, response preferences for implied motion correlated with preferences for low-level visual features such as orientation and size. No correlation was found between the preferred view of figures implying motion and the preferred direction for moving random dot patterns. Similar findings were obtained in a smaller population of MST cortical neurons. Testing human MT+ responses with fMRI further corroborated the notion that low-level stimulus features might explain implied motion activation in human MT+. Together, these results suggest that prior human imaging studies demonstrating animate implied motion processing in area MT+ can be best explained by sensitivity for low-level features rather than sensitivity for the motion implied by animate figures. 2011-06-01T00:00:00Z Lorteije, Jeannette A. M. Barraclough, Nick E. Jellema, Tjeerd Raemaekers, Mathijs Duijnhouwer, Jacob Xiao, Dengke Oram, Mike W. Lankheet, Martin J. M. Perrett, David I. van Wezel, Richard J. A. To investigate form-related activity inmotion-sensitive cortical areas, we recorded cell responses to animate implied motion in macaque middle temporal (MT) and medial superior temporal (MST) cortex and investigated these areas using fMRI in humans. In the single-cell studies, we compared responses with static images of human or monkey figures walking or running left or right with responses to the same human and monkey figures standing or sitting still. We also investigated whether the view of the animate figure (facing left or right) that elicited the highest response was correlated with the preferred direction for moving random dot patterns. First, figures were presented inside the cell's receptive field. Subsequently, figures were presented at the fovea while a dynamic noise pattern was presented at the cell's receptive field location. The results show that MT neurons did not discriminate between figures on the basis of the implied motion content. Instead, response preferences for implied motion correlated with preferences for low-level visual features such as orientation and size. No correlation was found between the preferred view of figures implying motion and the preferred direction for moving random dot patterns. Similar findings were obtained in a smaller population of MST cortical neurons. Testing human MT+ responses with fMRI further corroborated the notion that low-level stimulus features might explain implied motion activation in human MT+. Together, these results suggest that prior human imaging studies demonstrating animate implied motion processing in area MT+ can be best explained by sensitivity for low-level features rather than sensitivity for the motion implied by animate figures. http://hdl.handle.net/10023/1994 2004-12-01T00:00:00Z Brown, Gillian Ruth Almond, REA van Bergen, Y http://hdl.handle.net/10023/1990 Abstract: Evolutionary Psychology (EP) views the human mind as organized into many modules, each underpinned by psychological adaptations designed to solve problems faced by our Pleistocene ancestors. We argue that the key tenets of the established EP paradigm require modification in the light of recent findings from a number of disciplines, including human genetics, evolutionary biology, cognitive neuroscience, developmental psychology, and paleoecology. For instance, many human genes have been subject to recent selective sweeps; humans play an active, constructive role in co-directing their own development and evolution; and experimental evidence often favours a general process, rather than a modular account, of cognition. A redefined EP could use the theoretical insights of modern evolutionary biology as a rich source of hypotheses concerning the human mind, and could exploit novel methods from a variety of adjacent research fields. 2011-07-19T00:00:00Z Bolhuis, Johan Brown, Gillian Ruth Richardson, Robert Laland, Kevin Neville Evolutionary Psychology (EP) views the human mind as organized into many modules, each underpinned by psychological adaptations designed to solve problems faced by our Pleistocene ancestors. We argue that the key tenets of the established EP paradigm require modification in the light of recent findings from a number of disciplines, including human genetics, evolutionary biology, cognitive neuroscience, developmental psychology, and paleoecology. For instance, many human genes have been subject to recent selective sweeps; humans play an active, constructive role in co-directing their own development and evolution; and experimental evidence often favours a general process, rather than a modular account, of cognition. A redefined EP could use the theoretical insights of modern evolutionary biology as a rich source of hypotheses concerning the human mind, and could exploit novel methods from a variety of adjacent research fields. http://hdl.handle.net/10023/1973 Abstract: While the gestural communication of apes is widely recognised as intentional and flexible, their vocal communication still remains considered as mostly genetically determined and emotionally bound. Trying to limit the direct projections of linguistic concepts, that are far from holding a unified view on what constitute human language, this thesis presents a detailed description of the pant-grunt vocalisation usage and development in the chimpanzees (Pan troglodytes schweinfurthii) of the Budongo forest, Uganda. Pant-grunts are one of the most social vocalisations of the chimpanzee vocal repertoire and are always given from a subordinate individual to a dominant. The question of how such a signal is used and develops is critical for our understanding of chimpanzee social and vocal complexity in an ontogenetical and phylogenetical perpective. Results suggest that pant-grunt vocalisations can be used in a flexible way, both in their form and usage within a social group. More specifically, chimpanzees seemed to take into account the number and identity of surrounding individuals before producing these vocalisations. At the acoustic level, pant-grunts seem to be very variable vocalisations that corresponded to different social situations commonly encountered. Grunts are one of the first vocalisations produced by babies but they are not first produced in social contexts. Although some modifications of the social grunts form and usage could not entirely be attributed to maturation only, the role of the mother seemed to be restricted. Her direct influence was perhaps more visible in the rhythmic patterns of chorusing events. Taken together, this thesis suggests that chimpanzee vocalisations are more flexible in their usage, production and acquisition than previously thought and might therefore be more similar to gestural communication. 2011-06-21T00:00:00Z Laporte, Marion N.C. While the gestural communication of apes is widely recognised as intentional and flexible, their vocal communication still remains considered as mostly genetically determined and emotionally bound. Trying to limit the direct projections of linguistic concepts, that are far from holding a unified view on what constitute human language, this thesis presents a detailed description of the pant-grunt vocalisation usage and development in the chimpanzees (Pan troglodytes schweinfurthii) of the Budongo forest, Uganda. Pant-grunts are one of the most social vocalisations of the chimpanzee vocal repertoire and are always given from a subordinate individual to a dominant. The question of how such a signal is used and develops is critical for our understanding of chimpanzee social and vocal complexity in an ontogenetical and phylogenetical perpective. Results suggest that pant-grunt vocalisations can be used in a flexible way, both in their form and usage within a social group. More specifically, chimpanzees seemed to take into account the number and identity of surrounding individuals before producing these vocalisations. At the acoustic level, pant-grunts seem to be very variable vocalisations that corresponded to different social situations commonly encountered. Grunts are one of the first vocalisations produced by babies but they are not first produced in social contexts. Although some modifications of the social grunts form and usage could not entirely be attributed to maturation only, the role of the mother seemed to be restricted. Her direct influence was perhaps more visible in the rhythmic patterns of chorusing events. Taken together, this thesis suggests that chimpanzee vocalisations are more flexible in their usage, production and acquisition than previously thought and might therefore be more similar to gestural communication. http://hdl.handle.net/10023/1922 Abstract: This thesis investigates the use of binocular information for motion-in-depth (MID) perception. There are at least two different types of binocular information available to the visual system from which to derive a perception of MID: changing disparity (CD) and inter-ocular velocity differences (IOVD). In the following experiments, we manipulate the availability of CD and IOVD information in order to assess the relative influence of each on MID judgements. In the first experiment, we assessed the relative effectiveness of CD and IOVD information for MID detection, and whether the two types of binocular information are processed by separate mechanisms with differing characteristics. Our results suggest that, both CD and IOVD information can be utilised for MID detection, yet, the relative dependence on either of these types of MID information varies between observers. We then went on to explore the contribution of CD and IOVD information to time-to-contact (TTC) perception, whereby an observer judges the time at which an approaching stimulus will contact them. We confirmed that the addition of congruent binocular information to looming stimuli can influence TTC judgements, but that there is no influence from binocular information indicating no motion. Further to this, we found that observers could utilise both CD and IOVD for TTC judgements, although once again, individual receptiveness to CD and/or IOVD information varied. Thus, we demonstrate that the human visual system is able to process both CD and IOVD information, but the influence of either (or both) of these cues on an individual’s perception has been shown to be mutually independent. 2011-06-22T00:00:00Z Grafton, Catherine E. This thesis investigates the use of binocular information for motion-in-depth (MID) perception. There are at least two different types of binocular information available to the visual system from which to derive a perception of MID: changing disparity (CD) and inter-ocular velocity differences (IOVD). In the following experiments, we manipulate the availability of CD and IOVD information in order to assess the relative influence of each on MID judgements. In the first experiment, we assessed the relative effectiveness of CD and IOVD information for MID detection, and whether the two types of binocular information are processed by separate mechanisms with differing characteristics. Our results suggest that, both CD and IOVD information can be utilised for MID detection, yet, the relative dependence on either of these types of MID information varies between observers. We then went on to explore the contribution of CD and IOVD information to time-to-contact (TTC) perception, whereby an observer judges the time at which an approaching stimulus will contact them. We confirmed that the addition of congruent binocular information to looming stimuli can influence TTC judgements, but that there is no influence from binocular information indicating no motion. Further to this, we found that observers could utilise both CD and IOVD for TTC judgements, although once again, individual receptiveness to CD and/or IOVD information varied. Thus, we demonstrate that the human visual system is able to process both CD and IOVD information, but the influence of either (or both) of these cues on an individual’s perception has been shown to be mutually independent. http://hdl.handle.net/10023/1893 Abstract: A central issue in the study of primate communication is the extent to which individuals adjust their behaviour to the attention and signals of others, and manipulate others’ attention to communicate about external events. I investigated whether 13 chimpanzees (Pan troglodytes spp.), 11 bonobos (Pan paniscus), and 7 orangutans (Pongo pygmaeus pygmaeus) followed conspecific attention and led others to distal locations. Individuals were presented with a novel stimulus, to test if they would lead a conspecific to detect it in two experimental conditions. In one the conspecific faced the communicator, while another required the communicator to first attract the attention of a conspecific. All species followed conspecific attention, but only bonobos in conditions that required geometric attention following and that the communicator first attract the conspecific‘s attention. There was a clear trend for the chimpanzees to selectively produce a stimulus directional ‘hunching’ posture when viewing the stimulus in the presence of a conspecific rather than alone (the comparison was statistically non-significant, but very closely approached significance [p = 0.056]), and the behaviour consistently led conspecifics to look towards the stimulus. An observational study showed that ‘hunching’ only occurred in the context of attention following. Some chimpanzees and bonobos consistently and selectively combined functionally different behaviours (consisting of sequential auditory-stimulus-directional-behaviours), when viewing the stimulus in the presence of a non-attentive conspecific, although at species level this did not yield significant effects. While the design did not eliminate the possibility of a social referencing motive (“look and help me decide how to respond”), the coupling of auditory cues followed by directional cues towards a novel object, is consistent with a declarative and social referential interpretation of non-verbal deixis. An exploratory study, which applied the ‘Social Attention Hypothesis’ (that individuals accord and receive attention as a function of dominance) to attention following, showed that chimpanzees were more likely to follow the attention of the dominant individual. Overall, the results suggest that the paucity of observed referential behaviours in apes may owe to the inconspicuousness and multi-faceted nature of the behaviours. 2011-06-22T00:00:00Z Madsen, Elainie Alenkær A central issue in the study of primate communication is the extent to which individuals adjust their behaviour to the attention and signals of others, and manipulate others’ attention to communicate about external events. I investigated whether 13 chimpanzees (Pan troglodytes spp.), 11 bonobos (Pan paniscus), and 7 orangutans (Pongo pygmaeus pygmaeus) followed conspecific attention and led others to distal locations. Individuals were presented with a novel stimulus, to test if they would lead a conspecific to detect it in two experimental conditions. In one the conspecific faced the communicator, while another required the communicator to first attract the attention of a conspecific. All species followed conspecific attention, but only bonobos in conditions that required geometric attention following and that the communicator first attract the conspecific‘s attention. There was a clear trend for the chimpanzees to selectively produce a stimulus directional ‘hunching’ posture when viewing the stimulus in the presence of a conspecific rather than alone (the comparison was statistically non-significant, but very closely approached significance [p = 0.056]), and the behaviour consistently led conspecifics to look towards the stimulus. An observational study showed that ‘hunching’ only occurred in the context of attention following. Some chimpanzees and bonobos consistently and selectively combined functionally different behaviours (consisting of sequential auditory-stimulus-directional-behaviours), when viewing the stimulus in the presence of a non-attentive conspecific, although at species level this did not yield significant effects. While the design did not eliminate the possibility of a social referencing motive (“look and help me decide how to respond”), the coupling of auditory cues followed by directional cues towards a novel object, is consistent with a declarative and social referential interpretation of non-verbal deixis. An exploratory study, which applied the ‘Social Attention Hypothesis’ (that individuals accord and receive attention as a function of dominance) to attention following, showed that chimpanzees were more likely to follow the attention of the dominant individual. Overall, the results suggest that the paucity of observed referential behaviours in apes may owe to the inconspicuousness and multi-faceted nature of the behaviours. http://hdl.handle.net/10023/1868 Abstract: n humans, novelty-seeking behavior peaks in adolescence and is higher in males than females. Relatively, little information is available regarding age and sex differences in response to novelty in rodents. In this study, male and female Lister-hooded rats were tested at early adolescence (postnatal day, pnd, 28), mid-adolescence (pnd 40), or early adulthood (pnd 80) in a novel object recognition task (n = 12 males/females per age group). Males displayed a higher preference for the novel object than females at mid-adolescence, with no sex difference at early adolescence. Adult females interacted with the novel object more than adult males, but not when side biases were removed. Sex differences at mid-adolescence were not found in other measures, suggesting that the difference at this age was specific to situations involving choice of novelty. The results are considered in the context of age- and sex-dependent interactions between gonadal hormones and the dopamine system. Description: This work was supported by The Wellcome Trust [grant 078405/Z/05/Z] 2011-11-01T00:00:00Z Cyrenne, De-Laine Brown, Gillian Ruth n humans, novelty-seeking behavior peaks in adolescence and is higher in males than females. Relatively, little information is available regarding age and sex differences in response to novelty in rodents. In this study, male and female Lister-hooded rats were tested at early adolescence (postnatal day, pnd, 28), mid-adolescence (pnd 40), or early adulthood (pnd 80) in a novel object recognition task (n = 12 males/females per age group). Males displayed a higher preference for the novel object than females at mid-adolescence, with no sex difference at early adolescence. Adult females interacted with the novel object more than adult males, but not when side biases were removed. Sex differences at mid-adolescence were not found in other measures, suggesting that the difference at this age was specific to situations involving choice of novelty. The results are considered in the context of age- and sex-dependent interactions between gonadal hormones and the dopamine system. http://hdl.handle.net/10023/1842 Abstract: Despite having being discovered nearly 80 years ago, bonobos (Pan paniscus) are still one of the least well understood of the great apes, largely remaining in the shadow of their better known cousins, the chimpanzees (Pan troglodytes). This is especially evident in the domain of communication, with bonobo vocal behaviour still a neglected field of study, especially compared to that of chimpanzees. In this thesis, I address this issue by exploring the natural vocal communication of bonobos and its underlying cognition, focusing on the role that vocalisations play during two key contexts, food discovery and sex. In the context of food-discovery, I combine observational and experimental techniques to examine whether bonobos produce and understand vocalisations that convey meaningful information about the quality of food encountered by the caller. Results indicate that bonobos produce an array of vocalisations when finding food, and combine different food-associated calls together into sequences in a way that relates to perceived food quality. In a subsequent playback study, it was demonstrated that receivers are able to extract meaning about perceived food quality by attending to these calls and integrating information across call sequences. In the context of sexual interactions, I examine the acoustic structure of female copulation calls, as well as patterns in call usage, to explore how these signals are used by individuals. My results show that females emit copulation calls in similar ways with both male and female partners, suggesting that these signals have become partly divorced from a function in reproduction, to assume a greater social role. Overall, my results highlight the relevance of studying primate vocalisations to investigate the underlying cognition and suggest that vocalisations are important behavioural tools for bonobos to navigate their social and physical worlds. 2011-06-01T00:00:00Z Clay, Zanna Despite having being discovered nearly 80 years ago, bonobos (Pan paniscus) are still one of the least well understood of the great apes, largely remaining in the shadow of their better known cousins, the chimpanzees (Pan troglodytes). This is especially evident in the domain of communication, with bonobo vocal behaviour still a neglected field of study, especially compared to that of chimpanzees. In this thesis, I address this issue by exploring the natural vocal communication of bonobos and its underlying cognition, focusing on the role that vocalisations play during two key contexts, food discovery and sex. In the context of food-discovery, I combine observational and experimental techniques to examine whether bonobos produce and understand vocalisations that convey meaningful information about the quality of food encountered by the caller. Results indicate that bonobos produce an array of vocalisations when finding food, and combine different food-associated calls together into sequences in a way that relates to perceived food quality. In a subsequent playback study, it was demonstrated that receivers are able to extract meaning about perceived food quality by attending to these calls and integrating information across call sequences. In the context of sexual interactions, I examine the acoustic structure of female copulation calls, as well as patterns in call usage, to explore how these signals are used by individuals. My results show that females emit copulation calls in similar ways with both male and female partners, suggesting that these signals have become partly divorced from a function in reproduction, to assume a greater social role. Overall, my results highlight the relevance of studying primate vocalisations to investigate the underlying cognition and suggest that vocalisations are important behavioural tools for bonobos to navigate their social and physical worlds. http://hdl.handle.net/10023/1799 Abstract: Current decision models of recognition memory are based almost entirely on one paradigm, single item old/new judgments accompanied by confidence ratings. This task results in receiver operating characteristics (ROCs) that are well fit by both signal-detection and dual-process models. Here we examine an entirely new recognition task, the judgment of episodic oddity, whereby participants select the mnemonically odd members of triplets (e.g., a new item hidden among two studied items). Using the only two known signal-detection rules of oddity judgment derived from the sensory perception literature, the unequal variance signal-detection model predicted that an old item among two new items would be easier to discover than a new item among two old items. In contrast, four separate empirical studies demonstrated the reverse pattern: triplets with two old items were the easiest to resolve. This finding was anticipated by the dual-process approach as the presence of two old items affords the greatest opportunity for recollection. Furthermore, a bootstrap-fed Monte Carlo procedure using two independent datasets demonstrated that the dual-process parameters typically observed during single item recognition correctly predict the current oddity findings, whereas unequal variance signal-detection parameters do not. Episodic oddity judgments represent a case where dual- and single-process predictions qualitatively diverge and the findings demonstrate that novelty is "odder" than familiarity. 2011-05-01T00:00:00Z O'Connor, Akira Robert Guhl, Emily Cox, Justin Dobbins, Ian Current decision models of recognition memory are based almost entirely on one paradigm, single item old/new judgments accompanied by confidence ratings. This task results in receiver operating characteristics (ROCs) that are well fit by both signal-detection and dual-process models. Here we examine an entirely new recognition task, the judgment of episodic oddity, whereby participants select the mnemonically odd members of triplets (e.g., a new item hidden among two studied items). Using the only two known signal-detection rules of oddity judgment derived from the sensory perception literature, the unequal variance signal-detection model predicted that an old item among two new items would be easier to discover than a new item among two old items. In contrast, four separate empirical studies demonstrated the reverse pattern: triplets with two old items were the easiest to resolve. This finding was anticipated by the dual-process approach as the presence of two old items affords the greatest opportunity for recollection. Furthermore, a bootstrap-fed Monte Carlo procedure using two independent datasets demonstrated that the dual-process parameters typically observed during single item recognition correctly predict the current oddity findings, whereas unequal variance signal-detection parameters do not. Episodic oddity judgments represent a case where dual- and single-process predictions qualitatively diverge and the findings demonstrate that novelty is "odder" than familiarity. http://hdl.handle.net/10023/1770 Abstract: In human beings, susceptibility to anxiety disorders can be relatively high during adolescence. Understanding the ontogeny of anxiety-like behavior in laboratory rodents has implications for developing anxiolytic drugs that are suitable for this age group. Given the dearth of information about adolescent rodents, this study examined the response of both male and female adolescent, late adolescent, young adult, and older adult rats to three tests of anxiety-like behavior: the emergence test (ET), open field (OF), and elevated plus-maze (EPM). The results showed that adolescent rats exhibited a higher anxiety-like response than adults on each test; the amount of locomotion in the OF and percentage of time spent on the open arms of the EPM increased across the age groups, while older adult rats made the fewest start box re-entries in the ET. These results support the hypothesis that adolescent rats have a more pronounced response to stressors than do adults. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 52: 731–739, 2010. Description: Funding provided for Gillian Brown by Wellcome Trust grant 078405/Z/05/Z 2010-12-01T00:00:00Z Lynn, Debra Alana Brown, Gillian Ruth In human beings, susceptibility to anxiety disorders can be relatively high during adolescence. Understanding the ontogeny of anxiety-like behavior in laboratory rodents has implications for developing anxiolytic drugs that are suitable for this age group. Given the dearth of information about adolescent rodents, this study examined the response of both male and female adolescent, late adolescent, young adult, and older adult rats to three tests of anxiety-like behavior: the emergence test (ET), open field (OF), and elevated plus-maze (EPM). The results showed that adolescent rats exhibited a higher anxiety-like response than adults on each test; the amount of locomotion in the OF and percentage of time spent on the open arms of the EPM increased across the age groups, while older adult rats made the fewest start box re-entries in the ET. These results support the hypothesis that adolescent rats have a more pronounced response to stressors than do adults. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 52: 731–739, 2010. http://hdl.handle.net/10023/1748 Abstract: A self-regulatory framework for distinguishing between shame and guilt was tested in three studies. Recently, two forms of moral regulation based on approach versus avoidance motivation have been proposed in the literature. Proscriptive regulation is sensitive to negative outcomes, inhibition based, and focused on what we should not do. Prescriptive regulation is sensitive to positive outcomes, activation based, and focused on what we should do. In the current research, consistent support was found for shame’s proscriptive and guilt’s prescriptive moral underpinnings. Study 1 found a positive association between avoidance orientation and shame proneness and between approach orientation and guilt proneness. In Study 2, priming a proscriptive orientation increased shame and priming a prescriptive orientation increased guilt. In Study 3, transgressions most apt to represent proscriptive and prescriptive violations predicted subsequent judgments of shame and guilt, respectively. This self-regulatory perspective provides a broad interpretive framework for understanding and extending past research findings. 2010-02-01T00:00:00Z Sheikh, Sana Janoff-Bulman, Ronnie A self-regulatory framework for distinguishing between shame and guilt was tested in three studies. Recently, two forms of moral regulation based on approach versus avoidance motivation have been proposed in the literature. Proscriptive regulation is sensitive to negative outcomes, inhibition based, and focused on what we should not do. Prescriptive regulation is sensitive to positive outcomes, activation based, and focused on what we should do. In the current research, consistent support was found for shame’s proscriptive and guilt’s prescriptive moral underpinnings. Study 1 found a positive association between avoidance orientation and shame proneness and between approach orientation and guilt proneness. In Study 2, priming a proscriptive orientation increased shame and priming a prescriptive orientation increased guilt. In Study 3, transgressions most apt to represent proscriptive and prescriptive violations predicted subsequent judgments of shame and guilt, respectively. This self-regulatory perspective provides a broad interpretive framework for understanding and extending past research findings. http://hdl.handle.net/10023/1747 Abstract: A distinction is made between two forms of morality on the basis of approach–avoidance differences in self-regulation. Prescriptive morality is sensitive to positive outcomes, activation-based, and focused on what we should do. Proscriptive morality is sensitive to negative outcomes, inhibition-based, and focused on what we should not do. Seven studies profile these two faces of morality, support their distinct motivational underpinnings, and provide evidence of moral asymmetry. Both are well-represented in individuals' moral repertoire and equivalent in terms of moral weight, but proscriptive morality is condemnatory and strict, whereas prescriptive morality is commendatory and not strict. More specifically, in these studies proscriptive morality was perceived as concrete, mandatory, and duty-based, whereas prescriptive morality was perceived as more abstract, discretionary, and based in duty or desire; proscriptive immorality resulted in greater blame, whereas prescriptive morality resulted in greater moral credit. Implications for broader social regulation, including cross-cultural differences and political orientation, are discussed. 2009-03-01T00:00:00Z Janoff-Bulman, Ronnie Sheikh, Sana Hepp, Sebastian A distinction is made between two forms of morality on the basis of approach–avoidance differences in self-regulation. Prescriptive morality is sensitive to positive outcomes, activation-based, and focused on what we should do. Proscriptive morality is sensitive to negative outcomes, inhibition-based, and focused on what we should not do. Seven studies profile these two faces of morality, support their distinct motivational underpinnings, and provide evidence of moral asymmetry. Both are well-represented in individuals' moral repertoire and equivalent in terms of moral weight, but proscriptive morality is condemnatory and strict, whereas prescriptive morality is commendatory and not strict. More specifically, in these studies proscriptive morality was perceived as concrete, mandatory, and duty-based, whereas prescriptive morality was perceived as more abstract, discretionary, and based in duty or desire; proscriptive immorality resulted in greater blame, whereas prescriptive morality resulted in greater moral credit. Implications for broader social regulation, including cross-cultural differences and political orientation, are discussed. http://hdl.handle.net/10023/1746 Abstract: Recent critiques of moral psychology and the contemporary culture wars highlight the need for a better understanding of diverse moral perspectives. A model of moral motives is proposed. The fundamental approach-avoidance distinction in motivation is crossed with self-other focus to create four moral motives: Self-Restraint (avoidance-self), Social Order (avoidance-other), Self-Reliance (approach-self), and Social Justice (approach-other). Three studies explored these motives in the context of political orientation. Overall, political conservatism was associated with avoidance motives and liberalism with approach motives. Approach-avoidance motives were also associated with distinct patterns of results regarding authoritarianism, social dominance, and positions on contemporary social issues. Responses of campus political groups demonstrated the utility of the moral motives in providing a more nuanced view of politics that also takes into account the model's second dimension, for an emphasis on Self focus (personality responsibility) versus Other focus (social responsibility) further distinguished between conservative groups. Moral and political implications are discussed. 2008-07-01T00:00:00Z Janoff-Bulman, Ronnie Sheikh, Sana Baldacci, Kate Recent critiques of moral psychology and the contemporary culture wars highlight the need for a better understanding of diverse moral perspectives. A model of moral motives is proposed. The fundamental approach-avoidance distinction in motivation is crossed with self-other focus to create four moral motives: Self-Restraint (avoidance-self), Social Order (avoidance-other), Self-Reliance (approach-self), and Social Justice (approach-other). Three studies explored these motives in the context of political orientation. Overall, political conservatism was associated with avoidance motives and liberalism with approach motives. Approach-avoidance motives were also associated with distinct patterns of results regarding authoritarianism, social dominance, and positions on contemporary social issues. Responses of campus political groups demonstrated the utility of the moral motives in providing a more nuanced view of politics that also takes into account the model's second dimension, for an emphasis on Self focus (personality responsibility) versus Other focus (social responsibility) further distinguished between conservative groups. Moral and political implications are discussed. http://hdl.handle.net/10023/1688 Abstract: The loud songs of gibbons (Hylobatidae) usually consist of a duet by the mated pair delivered each morning. These songs can transmit over a kilometre through dense forest habitat and therefore presumably play a role in long-distance communication. There is some evidence to suggest that gibbons use song in contexts other than their daily duets, such as predation, but these songs have not been well studied. Close- range communication is also relevant for gibbons, but these quieter calls have completely escaped any detailed observation. The responses of wild white-handed gibbons (Hylobates lar) to simulated visual and acoustic predators (tiger, clouded leopard, reticulated python and crested serpent eagle) were studied in Khao Yai National Park, Thailand to address the lack of empirical data about these important events. Little is known about gibbons’ anti- predatory behaviour in general, and simulated predator encounters provided an opportunity to investigate these responses as well. Results showed that gibbons used song as part of their anti-predator strategy and that subtle combinatorial changes were meaningful to conspecifics. They also showed marked behavioural changes in the short-term, and some evidence of longer-term changes as well. Quiet calls were also part of the gibbons’ response repertoire with the hoo call being particularly relevant. Hoos were used as a prelude to singing both normal duets and predator songs, but there were consistent differences between each context. Hoos were also delivered independently in a number of other contexts outside predation. When analysed, these hoos showed consistent contextual differences in a number of spectral parameters. Within the duet context, important contextual subtleties were evident also revealing a remarkable vocal plasticity. In addition, gibbons voluntarily attended to specific vocal elements of other gibbon duets, indicating that certain sequences are more pertinent than others. Results suggest both gibbon song and gibbon hoos are powerful communication tools that reliably reference external objects and events; this ability is also a critical feature of human language. 2010-01-01T00:00:00Z Clarke, Esther A. E. The loud songs of gibbons (Hylobatidae) usually consist of a duet by the mated pair delivered each morning. These songs can transmit over a kilometre through dense forest habitat and therefore presumably play a role in long-distance communication. There is some evidence to suggest that gibbons use song in contexts other than their daily duets, such as predation, but these songs have not been well studied. Close- range communication is also relevant for gibbons, but these quieter calls have completely escaped any detailed observation. The responses of wild white-handed gibbons (Hylobates lar) to simulated visual and acoustic predators (tiger, clouded leopard, reticulated python and crested serpent eagle) were studied in Khao Yai National Park, Thailand to address the lack of empirical data about these important events. Little is known about gibbons’ anti- predatory behaviour in general, and simulated predator encounters provided an opportunity to investigate these responses as well. Results showed that gibbons used song as part of their anti-predator strategy and that subtle combinatorial changes were meaningful to conspecifics. They also showed marked behavioural changes in the short-term, and some evidence of longer-term changes as well. Quiet calls were also part of the gibbons’ response repertoire with the hoo call being particularly relevant. Hoos were used as a prelude to singing both normal duets and predator songs, but there were consistent differences between each context. Hoos were also delivered independently in a number of other contexts outside predation. When analysed, these hoos showed consistent contextual differences in a number of spectral parameters. Within the duet context, important contextual subtleties were evident also revealing a remarkable vocal plasticity. In addition, gibbons voluntarily attended to specific vocal elements of other gibbon duets, indicating that certain sequences are more pertinent than others. Results suggest both gibbon song and gibbon hoos are powerful communication tools that reliably reference external objects and events; this ability is also a critical feature of human language. http://hdl.handle.net/10023/1651 Abstract: Although intergroup contact is one of the most prominent interventions to reduce prejudice, the generalization of contact effects is still a contentious issue. This research further examined the rarely studied secondary transfer effect (STE; Pettigrew, 2009), by which contact with a primary outgroup reduces prejudice toward secondary groups that are not directly involved in the contact. Across 3 cross-sectional studies conducted in Cyprus (N = 1,653), Northern Ireland (N = 1,973), and Texas (N = 275) and 1 longitudinal study conducted in Northern Ireland (N = 411), the present research sought to systematically rule out alternative accounts of the STE and to investigate 2 potential mediating mechanisms (ingroup reappraisal and attitude generalization). Results indicated that, consistent with the STE, contact with a primary outgroup predicts attitudes toward secondary outgroups, over and above contact with the secondary outgroup, socially desirable responding, and prior attitudes. Mediation analyses found strong evidence for attitude generalization but only limited evidence for ingroup reappraisal as an underlying process. Two out of 3 tests of a reverse model, where contact with the secondary outgroup predicts attitudes toward the primary outgroup, provide further evidence for an indirect effect through attitude generalization. Theoretical and practical implications of these results are discussed, and directions for future research are identified. 2010-08-01T00:00:00Z Tausch, Nicole Hewstone, Miles Kenworthy, Jared B. Psaltis, Charis Schmid, Katharina Popan, Jason R. Cairns, Ed Hughes, Joanne Although intergroup contact is one of the most prominent interventions to reduce prejudice, the generalization of contact effects is still a contentious issue. This research further examined the rarely studied secondary transfer effect (STE; Pettigrew, 2009), by which contact with a primary outgroup reduces prejudice toward secondary groups that are not directly involved in the contact. Across 3 cross-sectional studies conducted in Cyprus (N = 1,653), Northern Ireland (N = 1,973), and Texas (N = 275) and 1 longitudinal study conducted in Northern Ireland (N = 411), the present research sought to systematically rule out alternative accounts of the STE and to investigate 2 potential mediating mechanisms (ingroup reappraisal and attitude generalization). Results indicated that, consistent with the STE, contact with a primary outgroup predicts attitudes toward secondary outgroups, over and above contact with the secondary outgroup, socially desirable responding, and prior attitudes. Mediation analyses found strong evidence for attitude generalization but only limited evidence for ingroup reappraisal as an underlying process. Two out of 3 tests of a reverse model, where contact with the secondary outgroup predicts attitudes toward the primary outgroup, provide further evidence for an indirect effect through attitude generalization. Theoretical and practical implications of these results are discussed, and directions for future research are identified. http://hdl.handle.net/10023/1650 Abstract: We report the case of a 25-year-old healthy, blind male, MT, who experiences normal patterns of deja vu. The optical pathway delay theory of deja vu formation assumes that neuronal input from the optical pathways is necessary for the formation of the experience. Surprisingly, although the sensation of deja vu is known to be experienced by blind individuals, we believe this to be the first reported application of this knowledge to the understanding of the phenomenon. Visual input is not present in MT, yet the experiences he describes are consistent with reports in the literature of deja vu occurrence in sighted people. The fact that blind people can experience deja vu challenges the optical pathway delay theory, and alternative causes are briefly discussed. (c) 2006 Elsevier Inc. All rights reserved. 2006-12-01T00:00:00Z O'Connor, Akira R. Moulin, Christopher J. A. We report the case of a 25-year-old healthy, blind male, MT, who experiences normal patterns of deja vu. The optical pathway delay theory of deja vu formation assumes that neuronal input from the optical pathways is necessary for the formation of the experience. Surprisingly, although the sensation of deja vu is known to be experienced by blind individuals, we believe this to be the first reported application of this knowledge to the understanding of the phenomenon. Visual input is not present in MT, yet the experiences he describes are consistent with reports in the literature of deja vu occurrence in sighted people. The fact that blind people can experience deja vu challenges the optical pathway delay theory, and alternative causes are briefly discussed. (c) 2006 Elsevier Inc. All rights reserved. http://hdl.handle.net/10023/1649 Abstract: We report the case of a 39-year-old, temporal lobe epileptic male, MH. Prior to complex partial seizure, experienced up to three times a day, MH often experiences an aura experienced as a persistent sensation of deja vu. Data-driven theories of deja vu formation suggest that partial familiarity for the perceived stimulus is responsible for the sensation. Consequently, diverting attention away from this stimulus should cause the sensation to dissipate. MH, whose sensations of deja vu persist long enough for him to shift his perceptual focus a number of times during the experience, spontaneously reports that these shifts make no difference to the sensation experienced. This novel observation challenges data-driven theories of deja vu formation which have been used to explain the occurrence of deja vu in those with temporal lobe epilepsy and the general population. Clearly, in epilepsy, erratic neuronal firing is the likely contributor, and in this paper we postulate that such brain firing causes higher-order erroneous 'cognitive feelings'. We tentatively extend this account to the general population. Rather than being a reaction to familiar elements in perceptual stimuli, deja vu is likely to be the result of a cognitive feeling borne of the erroneous activation of neural familiarity circuits such as the parahippocampal gyrus, persisting as long as this activation persists. (c) 2008 Elsevier Inc. All rights reserved. 2008-11-01T00:00:00Z O'Connor, Akira R. Moulin, Christopher J. A. We report the case of a 39-year-old, temporal lobe epileptic male, MH. Prior to complex partial seizure, experienced up to three times a day, MH often experiences an aura experienced as a persistent sensation of deja vu. Data-driven theories of deja vu formation suggest that partial familiarity for the perceived stimulus is responsible for the sensation. Consequently, diverting attention away from this stimulus should cause the sensation to dissipate. MH, whose sensations of deja vu persist long enough for him to shift his perceptual focus a number of times during the experience, spontaneously reports that these shifts make no difference to the sensation experienced. This novel observation challenges data-driven theories of deja vu formation which have been used to explain the occurrence of deja vu in those with temporal lobe epilepsy and the general population. Clearly, in epilepsy, erratic neuronal firing is the likely contributor, and in this paper we postulate that such brain firing causes higher-order erroneous 'cognitive feelings'. We tentatively extend this account to the general population. Rather than being a reaction to familiar elements in perceptual stimuli, deja vu is likely to be the result of a cognitive feeling borne of the erroneous activation of neural familiarity circuits such as the parahippocampal gyrus, persisting as long as this activation persists. (c) 2008 Elsevier Inc. All rights reserved. http://hdl.handle.net/10023/1648 Abstract: Introduction. Despite current research interest in delusional beliefs, there are no viable models for studying delusions in the laboratory. However, hypnosis offers a technique for creating transient delusions that are resistant to challenge. The aim of this study was to develop an hypnotic analogue of one important delusion, mirrored-self misidentification. Methods. Twelve high hypnotisable participants received an hypnotic suggestion to see either a stranger in the mirror, a mirror as a window, or a mirror as a window with a view to a stranger. Participants' deluded beliefs were challenged, and following hypnosis, Sheehan and McConkey's (1982) Experiential Analysis Technique was used to explore participants' phenomenological experience of the delusion. Results. The majority of participants did not recognise their reflection in the mirror, described the person in the mirror as having different physical characteristics to themselves, and maintained their delusion when challenged. Conclusions. The hypnotic suggestion created a credible, compelling delusion with features strikingly similar to clinical cases of mirrored-self misidentification. Our findings suggest that Factor 2 within Langdon and Coltheart's (2000) two-factor framework may involve a lowering of the criteria used to accept or reject delusional hypotheses. 2008-09-01T00:00:00Z Barnier, Amanda Cox, Rochelle O'Connor, Akira Robert Coltheart, Max Langdon, Robyn Breen, Nora Turner, Martha Introduction. Despite current research interest in delusional beliefs, there are no viable models for studying delusions in the laboratory. However, hypnosis offers a technique for creating transient delusions that are resistant to challenge. The aim of this study was to develop an hypnotic analogue of one important delusion, mirrored-self misidentification. Methods. Twelve high hypnotisable participants received an hypnotic suggestion to see either a stranger in the mirror, a mirror as a window, or a mirror as a window with a view to a stranger. Participants' deluded beliefs were challenged, and following hypnosis, Sheehan and McConkey's (1982) Experiential Analysis Technique was used to explore participants' phenomenological experience of the delusion. Results. The majority of participants did not recognise their reflection in the mirror, described the person in the mirror as having different physical characteristics to themselves, and maintained their delusion when challenged. Conclusions. The hypnotic suggestion created a credible, compelling delusion with features strikingly similar to clinical cases of mirrored-self misidentification. Our findings suggest that Factor 2 within Langdon and Coltheart's (2000) two-factor framework may involve a lowering of the criteria used to accept or reject delusional hypotheses. http://hdl.handle.net/10023/1647 Abstract: This experiment aimed to create a laboratory analogue of deja vu. During hypnosis, 1 group of high hypnotizables completed a puzzle game and then received a posthypnotic amnesia suggestion to forget the game (PHA condition). Another group of highs were not given the game but received a posthypnotic familiarity suggestion that it would feel familiar (PHF condition). After hypnosis, all participants were given the game and described their reactions to it. Whereas 83% of participants in both conditions passed their respective suggestions, more in the PHF condition felt a sense of deja vu. An EAT inquiry revealed that they experienced sensory fascination and confusion about the source of familiarity, akin to everyday deja vu. These findings highlight the value of using hypnosis as a laboratory analogue of deja vu and provide a framework for investigating clinical manifestations of this phenomenon. 2008-10-01T00:00:00Z O'Connor, Akira R. Barnier, Amanda J. Cox, Rochelle E. This experiment aimed to create a laboratory analogue of deja vu. During hypnosis, 1 group of high hypnotizables completed a puzzle game and then received a posthypnotic amnesia suggestion to forget the game (PHA condition). Another group of highs were not given the game but received a posthypnotic familiarity suggestion that it would feel familiar (PHF condition). After hypnosis, all participants were given the game and described their reactions to it. Whereas 83% of participants in both conditions passed their respective suggestions, more in the PHF condition felt a sense of deja vu. An EAT inquiry revealed that they experienced sensory fascination and confusion about the source of familiarity, akin to everyday deja vu. These findings highlight the value of using hypnosis as a laboratory analogue of deja vu and provide a framework for investigating clinical manifestations of this phenomenon. http://hdl.handle.net/10023/1646 2008-01-01T00:00:00Z O'Connor, Akira Robert Moulin, Chris Cohen, Gillian http://hdl.handle.net/10023/1645 Abstract: The thesis of this paper is that deja experiences can be separated into two forms: deja vu, arising from the erroneous sensation of familiarity, and deja vecu, arising from the erroneous sensation of recollection. We summarise a series of cases for whom deja vecu is experienced frequently and for extended periods, and seek to differentiate their experiences from “healthy” deja experiences by nonbrain-damaged participants. In reviewing our cases, we stress two novel ideas: that deja vecu in these cases is delusion-like; and that these cases experience deja vecu for stimuli that are especially novel or unusual. Here we present a novel cognitive neuroscientific hypothesis of deja vecu. This hypothesis assumes that the signal of retrieval from memory is neurally dissociable from the contents of retrieval. We suggest that a region downstream of the hippocampus signals “recollection” by detecting the timing of firing in hippocampal output neurons relative to the theta oscillation. Disruptions to this “temporal coding” mechanism result in false signals of recollection which may occur without actual retrieval and which, ironically, may arise particularly during situations of contextual novelty. 2010-01-01T00:00:00Z O'Connor, Akira Robert Lever, Colin Moulin, Chris The thesis of this paper is that deja experiences can be separated into two forms: deja vu, arising from the erroneous sensation of familiarity, and deja vecu, arising from the erroneous sensation of recollection. We summarise a series of cases for whom deja vecu is experienced frequently and for extended periods, and seek to differentiate their experiences from “healthy” deja experiences by nonbrain-damaged participants. In reviewing our cases, we stress two novel ideas: that deja vecu in these cases is delusion-like; and that these cases experience deja vecu for stimuli that are especially novel or unusual. Here we present a novel cognitive neuroscientific hypothesis of deja vecu. This hypothesis assumes that the signal of retrieval from memory is neurally dissociable from the contents of retrieval. We suggest that a region downstream of the hippocampus signals “recollection” by detecting the timing of firing in hippocampal output neurons relative to the theta oscillation. Disruptions to this “temporal coding” mechanism result in false signals of recollection which may occur without actual retrieval and which, ironically, may arise particularly during situations of contextual novelty. http://hdl.handle.net/10023/1643 Abstract: During adolescence, rats gain independence from their mothers and disperse from the natal burrow, with males typically dispersing further than females. We predicted that, if dispersal patterns are associated with responsiveness to novelty, exploratory behavior in novel environments would increase across adolescence, and males would explore more than females. Alternatively, females might explore more than males, if females are more motivated than males to learn about the immediate environment or if females have poorer spatial abilities than males. Twenty-five male and 21 female rats were exposed to two novel environments (open field and elevated plus-maze) during early, mid-, or late adolescence. Total locomotion and amount of exploration directed towards aversive areas increased across adolescence, even when body weight was included as a covariate. Female adolescents locomoted more and spent more time exploring aversive areas than males. Developmental changes in neural function potentially underlie age and sex differences in exploratory, behavior (C) 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 513-520, 2009. Description: Supported by Wellcome Trust grant 078405/Z/05/Z 2009-09-01T00:00:00Z Lynn, D. A. Brown, Gillian Ruth During adolescence, rats gain independence from their mothers and disperse from the natal burrow, with males typically dispersing further than females. We predicted that, if dispersal patterns are associated with responsiveness to novelty, exploratory behavior in novel environments would increase across adolescence, and males would explore more than females. Alternatively, females might explore more than males, if females are more motivated than males to learn about the immediate environment or if females have poorer spatial abilities than males. Twenty-five male and 21 female rats were exposed to two novel environments (open field and elevated plus-maze) during early, mid-, or late adolescence. Total locomotion and amount of exploration directed towards aversive areas increased across adolescence, even when body weight was included as a covariate. Female adolescents locomoted more and spent more time exploring aversive areas than males. Developmental changes in neural function potentially underlie age and sex differences in exploratory, behavior (C) 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 513-520, 2009. http://hdl.handle.net/10023/1639 Abstract: Déjà vu is characterized by the recognition of a situation concurrent with the awareness that this recognition is inappropriate. Although forms of déjà vu resolve in favor of the inappropriate recognition and therefore have behavioral consequences, typical déjà vu experiences resolve in favor of the awareness that the sensation of recognition is inappropriate. The resultant lack of behavioral modification associated with typical déjà vu means that clinicians and experimenters rely heavily on self-report when observing the experience. In this review, we focus on recent déjà vu research. We consider issues facing neuropsychological, neuroscientific, and cognitive experimental frameworks attempting to explore and experimentally generate the experience. In doing this, we suggest the need for more experimentation and amore cautious interpretation of research findings, particularly as many techniques being used to explore déjà vu are in the early stages of development. 2010-06-01T00:00:00Z O'Connor, Akira Robert Moulin, Chris Déjà vu is characterized by the recognition of a situation concurrent with the awareness that this recognition is inappropriate. Although forms of déjà vu resolve in favor of the inappropriate recognition and therefore have behavioral consequences, typical déjà vu experiences resolve in favor of the awareness that the sensation of recognition is inappropriate. The resultant lack of behavioral modification associated with typical déjà vu means that clinicians and experimenters rely heavily on self-report when observing the experience. In this review, we focus on recent déjà vu research. We consider issues facing neuropsychological, neuroscientific, and cognitive experimental frameworks attempting to explore and experimentally generate the experience. In doing this, we suggest the need for more experimentation and amore cautious interpretation of research findings, particularly as many techniques being used to explore déjà vu are in the early stages of development. http://hdl.handle.net/10023/1637 Abstract: Functional neuroimaging studies of episodic recognition demonstrate an increased lateral parietal response for studied versus new materials, often termed a retrieval success effect. Using a novel memory analog of attentional cueing, we manipulated the correspondence between anticipated and actual recognition evidence by presenting valid or invalid anticipatory cues (e. g., "likely old") before recognition judgments. Although a superior parietal region demonstrated the retrieval success pattern, a larger inferior parietal lobule (IPL) region tracked the validity of the memory cueing (invalid cueing > valid cueing) and no retrieval success-sensitive lateral parietal region was insensitive to cueing. The invalid cueing response occurred even for correctly identified new items unlikely to trigger substantive episodic retrieval. Within the IPL, although supramarginal and angular gyrus (SMG; AG) regions both demonstrated invalid cueing amplitude elevations, each region differentially coupled with distinct cortical networks when unexpectedly old items were encountered; a connectivity pattern also observed at rest in the same subjects. These findings jointly suggest that the lateral parietal response during recognition does not signify the recovery of episodic content, but is a marker of the violation of memory expectations. A second independent dataset confirmed this interpretation by demonstrating that SMG activation tracked the decision biases of observers, not their accuracy, with increased activation for nondominant recognition judgments. The expectancy violation interpretation of the lateral parietal recognition response is consistent with the literature on visual search and oddball paradigms and suggests that damage to these regions should impair memory-linked orienting behavior and not retrieval per se. 2010-02-24T00:00:00Z O'Connor, Akira R. Han, Sanghoon Dobbins, Ian G. Functional neuroimaging studies of episodic recognition demonstrate an increased lateral parietal response for studied versus new materials, often termed a retrieval success effect. Using a novel memory analog of attentional cueing, we manipulated the correspondence between anticipated and actual recognition evidence by presenting valid or invalid anticipatory cues (e. g., "likely old") before recognition judgments. Although a superior parietal region demonstrated the retrieval success pattern, a larger inferior parietal lobule (IPL) region tracked the validity of the memory cueing (invalid cueing > valid cueing) and no retrieval success-sensitive lateral parietal region was insensitive to cueing. The invalid cueing response occurred even for correctly identified new items unlikely to trigger substantive episodic retrieval. Within the IPL, although supramarginal and angular gyrus (SMG; AG) regions both demonstrated invalid cueing amplitude elevations, each region differentially coupled with distinct cortical networks when unexpectedly old items were encountered; a connectivity pattern also observed at rest in the same subjects. These findings jointly suggest that the lateral parietal response during recognition does not signify the recovery of episodic content, but is a marker of the violation of memory expectations. A second independent dataset confirmed this interpretation by demonstrating that SMG activation tracked the decision biases of observers, not their accuracy, with increased activation for nondominant recognition judgments. The expectancy violation interpretation of the lateral parietal recognition response is consistent with the literature on visual search and oddball paradigms and suggests that damage to these regions should impair memory-linked orienting behavior and not retrieval per se. http://hdl.handle.net/10023/1622 Abstract: Flexibility in the output of spinal networks can be accomplished by the actions of neuromodulators; however, little is known about how the process of neuromodulation itself may be modulated. Here we investigate the potential "meta"-modulatory hierarchy between nitric oxide (NO) and noradrenaline (NA) in Xenopus laevis tadpoles. NO and NA have similar effects on fictive swimming; both potentiate glycinergic inhibition to slow swimming frequency and GABAergic inhibition to reduce episode durations. In addition, both modulators have direct effects on the membrane properties of motor neurons. Here we report that antagonism of noradrenergic pathways with phentolamine dramatically influences the effect of the NO donor S-nitroso-N-acetylpenicillamine (SNAP) on swimming frequency, but not its effect on episode durations. In contrast, scavenging extracellular NO with 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide(PTIO) does not influence any of the effects of NA on fictive swimming. These data place NO above NA in the metamodulatory hierarchy, strongly suggesting that NO works via a noradrenergic pathway to control glycine release but directly promotes GABA release. We confirmed this possibility using intracellular recordings from motor neurons. In support of a natural role for NO in the Xenopus locomotor network, PTIO not only antagonized all of the effects of SNAP on swimming but also, when applied on its own, modulated both swimming frequency and episode durations in addition to the underlying glycinergic and GABAergic pathways. Collectively, our results illustrate that NO and NA have parallel effects on motor neuron membrane properties and GABAergic inhibition, but that NO serially metamodulates glycinergic inhibition via NA. 2004-10-27T00:00:00Z McLean, DL Sillar, Keith Thomas Flexibility in the output of spinal networks can be accomplished by the actions of neuromodulators; however, little is known about how the process of neuromodulation itself may be modulated. Here we investigate the potential "meta"-modulatory hierarchy between nitric oxide (NO) and noradrenaline (NA) in Xenopus laevis tadpoles. NO and NA have similar effects on fictive swimming; both potentiate glycinergic inhibition to slow swimming frequency and GABAergic inhibition to reduce episode durations. In addition, both modulators have direct effects on the membrane properties of motor neurons. Here we report that antagonism of noradrenergic pathways with phentolamine dramatically influences the effect of the NO donor S-nitroso-N-acetylpenicillamine (SNAP) on swimming frequency, but not its effect on episode durations. In contrast, scavenging extracellular NO with 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide(PTIO) does not influence any of the effects of NA on fictive swimming. These data place NO above NA in the metamodulatory hierarchy, strongly suggesting that NO works via a noradrenergic pathway to control glycine release but directly promotes GABA release. We confirmed this possibility using intracellular recordings from motor neurons. In support of a natural role for NO in the Xenopus locomotor network, PTIO not only antagonized all of the effects of SNAP on swimming but also, when applied on its own, modulated both swimming frequency and episode durations in addition to the underlying glycinergic and GABAergic pathways. Collectively, our results illustrate that NO and NA have parallel effects on motor neuron membrane properties and GABAergic inhibition, but that NO serially metamodulates glycinergic inhibition via NA. http://hdl.handle.net/10023/1621 Abstract: The capacity of embryonic stem (ES) cells to form functional motoneurons (MNs) and appropriate connections with muscle was investigated in vitro. ES cells were obtained from a transgenic mouse line in which the gene for enhanced green fluorescent protein (eGFP) is expressed under the control of the promotor of the MN specific homeobox gene Hb9. ES cells were exposed to retinoic acid ( RA) and sonic hedgehog agonist (Hh-Ag1.3) to stimulate differentiation into MNs marked by expression of eGFP and the cholinergic transmitter synthetic enzyme choline acetyltransferase. Whole-cell patch-clamp recordings were made from eGFP-labeled cells to investigate the development of functional characteristics of MNs. In voltage-clamp mode, currents, including EPSCs, were recorded in response to exogenous applications of GABA, glycine, and glutamate. EGFP-labeled neurons also express voltage-activated ion channels including fast-inactivating Na+ channels, delayed rectifier and I-A-type K+ channels, and Ca2+ channels. Current-clamp recordings demonstrated that eGFP-positive neurons generate repetitive trains of action potentials and that L-type Ca2+ channels mediate sustained depolarizations. When cocultured with a muscle cell line, clustering of acetylcholine receptors on muscle fibers adjacent to developing axons was seen. Intracellular recordings of muscle fibers adjacent to eGFP-positive axons revealed endplate potentials that increased in amplitude and frequency after glutamate application and were sensitive to TTX and curare. In summary, our findings demonstrate that MNs derived from ES cells develop appropriate transmitter receptors, intrinsic properties necessary for appropriate patterns of action potential firing and functional synapses with muscle fibers. 2004-09-08T00:00:00Z Miles, Gareth Brian Yohn, D C Wichterle, H Jessell, T M Rafuse, V F Brownstone, R M The capacity of embryonic stem (ES) cells to form functional motoneurons (MNs) and appropriate connections with muscle was investigated in vitro. ES cells were obtained from a transgenic mouse line in which the gene for enhanced green fluorescent protein (eGFP) is expressed under the control of the promotor of the MN specific homeobox gene Hb9. ES cells were exposed to retinoic acid ( RA) and sonic hedgehog agonist (Hh-Ag1.3) to stimulate differentiation into MNs marked by expression of eGFP and the cholinergic transmitter synthetic enzyme choline acetyltransferase. Whole-cell patch-clamp recordings were made from eGFP-labeled cells to investigate the development of functional characteristics of MNs. In voltage-clamp mode, currents, including EPSCs, were recorded in response to exogenous applications of GABA, glycine, and glutamate. EGFP-labeled neurons also express voltage-activated ion channels including fast-inactivating Na+ channels, delayed rectifier and I-A-type K+ channels, and Ca2+ channels. Current-clamp recordings demonstrated that eGFP-positive neurons generate repetitive trains of action potentials and that L-type Ca2+ channels mediate sustained depolarizations. When cocultured with a muscle cell line, clustering of acetylcholine receptors on muscle fibers adjacent to developing axons was seen. Intracellular recordings of muscle fibers adjacent to eGFP-positive axons revealed endplate potentials that increased in amplitude and frequency after glutamate application and were sensitive to TTX and curare. In summary, our findings demonstrate that MNs derived from ES cells develop appropriate transmitter receptors, intrinsic properties necessary for appropriate patterns of action potential firing and functional synapses with muscle fibers. http://hdl.handle.net/10023/1612 Abstract: On many of the staple measures of comparative psychology, elephants show no obvious differences from other mammals, such as primates: discrimination learning, memory, spontaneous tool use, etc. However, a range of more naturalistic measures have recently suggested that elephant cognition may be rather different. Wild elephants sub-categorize humans into groups, independently making this classification on the basis of scent or colour. In number discrimination, elephants show no effects of absolute magnitude or relative size disparity in making number judgements. In the social realm, elephants show empathy into the problems faced by others, and give hints of special abilities in cooperation, vocal imitation and perhaps teaching. Field data suggest that the elephant’s vaunted reputation for memory may have a factual basis, in two ways. Elephants’ ability to remember large-scale space over long periods suggests good cognitive mapping skills. Elephants’ skill in keeping track of the current locations of many family members implies that working memory may be unusually developed, consistent with the laboratory finding that their quantity judgements do not show the usual magnitude effects. 2009-01-01T00:00:00Z Byrne, Richard William Bates, Lucy Moss, C J On many of the staple measures of comparative psychology, elephants show no obvious differences from other mammals, such as primates: discrimination learning, memory, spontaneous tool use, etc. However, a range of more naturalistic measures have recently suggested that elephant cognition may be rather different. Wild elephants sub-categorize humans into groups, independently making this classification on the basis of scent or colour. In number discrimination, elephants show no effects of absolute magnitude or relative size disparity in making number judgements. In the social realm, elephants show empathy into the problems faced by others, and give hints of special abilities in cooperation, vocal imitation and perhaps teaching. Field data suggest that the elephant’s vaunted reputation for memory may have a factual basis, in two ways. Elephants’ ability to remember large-scale space over long periods suggests good cognitive mapping skills. Elephants’ skill in keeping track of the current locations of many family members implies that working memory may be unusually developed, consistent with the laboratory finding that their quantity judgements do not show the usual magnitude effects. http://hdl.handle.net/10023/1596 Abstract: Transforming facial images along perceived dimensions (such as age, gender, race, or health) has application in areas as diverse as psychology, medicine, and forensics. We can use prototype images to define the salient features of a particular face classification (for example, European female adult or East-Asian male child). We then use the differences between two prototypes to define an axis of transformation, such as younger to older. By applying these changes to a given input face, we can change its apparent age, race, or gender. Psychological investigations reveal a limitation with existing methods that's particularly apparent when changing the age of faces. We relate the problem to the loss of facial textures (such as stubble and wrinkles) in the prototypes due to the blending process. We review the existing face prototyping and transformation methods and present a new, wavelet-based method for prototyping and transforming facial textures. 2001-09-01T00:00:00Z Tiddeman, Bernard Paul Perrett, David Ian Burt, D.M. Transforming facial images along perceived dimensions (such as age, gender, race, or health) has application in areas as diverse as psychology, medicine, and forensics. We can use prototype images to define the salient features of a particular face classification (for example, European female adult or East-Asian male child). We then use the differences between two prototypes to define an axis of transformation, such as younger to older. By applying these changes to a given input face, we can change its apparent age, race, or gender. Psychological investigations reveal a limitation with existing methods that's particularly apparent when changing the age of faces. We relate the problem to the loss of facial textures (such as stubble and wrinkles) in the prototypes due to the blending process. We review the existing face prototyping and transformation methods and present a new, wavelet-based method for prototyping and transforming facial textures. http://hdl.handle.net/10023/1592 Abstract: We present an exact Bayesian treatment of a simple, yet sufficiently general probability distribution model. We consider piecewise-constant distributions' P(X) with uniform (second-order) prior over location of discontinuity points and assigned chances. The predictive distribution and the model complexity can be determined completely from the data in a computational time that is linear in the number of degrees of freedom and quadratic in the number of possible values of X. Furthermore, exact values of the expectations of entropies and their variances can be computed with polynomial effort. The expectation of the mutual information becomes thus available, too, and a strict upper bound on its variance. The resulting algorithm is particularly useful in experimental research areas where the number of available samples is severely limited (e.g., neurophysiology). Estimates on a simulated data set provide more accurate results than using a previously proposed method. 2005-11-01T00:00:00Z Endres, Dominik Maria Foldiak, Peter We present an exact Bayesian treatment of a simple, yet sufficiently general probability distribution model. We consider piecewise-constant distributions' P(X) with uniform (second-order) prior over location of discontinuity points and assigned chances. The predictive distribution and the model complexity can be determined completely from the data in a computational time that is linear in the number of degrees of freedom and quadratic in the number of possible values of X. Furthermore, exact values of the expectations of entropies and their variances can be computed with polynomial effort. The expectation of the mutual information becomes thus available, too, and a strict upper bound on its variance. The resulting algorithm is particularly useful in experimental research areas where the number of available samples is severely limited (e.g., neurophysiology). Estimates on a simulated data set provide more accurate results than using a previously proposed method. http://hdl.handle.net/10023/1591 Abstract: We introduce a metric for probability distributions, which is bounded, information-theoretically motivated, and has a natural Bayesian interpretation. The square root of the well-known chi(2) distance is an asymptotic approximation to it. Moreover, it is a close relative of the capacitory discrimination and Jensen-Shannon divergence. 2003-07-01T00:00:00Z Endres, Dominik Maria Schindelin, J E We introduce a metric for probability distributions, which is bounded, information-theoretically motivated, and has a natural Bayesian interpretation. The square root of the well-known chi(2) distance is an asymptotic approximation to it. Moreover, it is a close relative of the capacitory discrimination and Jensen-Shannon divergence. http://hdl.handle.net/10023/1589 Abstract: CIRCA lets those with short-term memory loss draw on reminiscences to converse with relatives and caregivers. The system, which software engineers, psychologists, and designers developed with caregiver input, features a touch screen that displays photos, music, video, text, and other materials to help those with dementia access long-term memory. 2007-05-01T00:00:00Z Alm, N Dye, R Gowans, G Campbell, J Astell, Arlene Jean Ellis, M CIRCA lets those with short-term memory loss draw on reminiscences to converse with relatives and caregivers. The system, which software engineers, psychologists, and designers developed with caregiver input, features a touch screen that displays photos, music, video, text, and other materials to help those with dementia access long-term memory. http://hdl.handle.net/10023/1587 Abstract: Spoken language is a result of the human capacity to assemble simple vocal units into more complex utterances, the basic carriers of semantic information. Not much is known about the evolutionary origins of this behaviour. The vocal abilities of non-human primates are relatively unimpressive in comparison, with gibbon songs being a rare exception. These apes assemble a repertoire of call notes into elaborate songs, which function to repel conspecific intruders, advertise pair bonds, and attract mates. We conducted a series of field experiments with white-handed gibbons at Khao Yai National Park, Thailand, which showed that this ape species uses songs also to protect themselves against predation. We compared the acoustic structure of predatory-induced songs with regular songs that were given as part of their daily routine. Predator-induced songs were identical to normal songs in the call note repertoire, but we found consistent differences in how the notes were assembled into songs. The responses of out-of-sight receivers demonstrated that these syntactic differences were meaningful to conspecifics. Our study provides the first evidence of referential signalling in a free-ranging ape species, based on a communication system that utilises combinatorial rules. 2006-12-20T00:00:00Z Clarke, Esther Reichard, Ulrich H. Zuberbuehler, Klaus Spoken language is a result of the human capacity to assemble simple vocal units into more complex utterances, the basic carriers of semantic information. Not much is known about the evolutionary origins of this behaviour. The vocal abilities of non-human primates are relatively unimpressive in comparison, with gibbon songs being a rare exception. These apes assemble a repertoire of call notes into elaborate songs, which function to repel conspecific intruders, advertise pair bonds, and attract mates. We conducted a series of field experiments with white-handed gibbons at Khao Yai National Park, Thailand, which showed that this ape species uses songs also to protect themselves against predation. We compared the acoustic structure of predatory-induced songs with regular songs that were given as part of their daily routine. Predator-induced songs were identical to normal songs in the call note repertoire, but we found consistent differences in how the notes were assembled into songs. The responses of out-of-sight receivers demonstrated that these syntactic differences were meaningful to conspecifics. Our study provides the first evidence of referential signalling in a free-ranging ape species, based on a communication system that utilises combinatorial rules. http://hdl.handle.net/10023/1396 Abstract: Female African elephants signal oestrus via chemicals in their urine, but they also exhibit characteristic changes to their posture, gait and behaviour when sexually receptive. Free-ranging females visually signal receptivity by holding their heads and tails high, walking with an exaggerated gait, and displaying increased tactile behaviour towards males. Parous females occasionally exhibit these visual signals at times when they are thought not to be cycling and without attracting interest from musth males. Using demographic and behavioural records spanning a continuous 28-year period, we investigated the occurrence of this “simulated” oestrus behaviour. We show that parous females in the Amboseli elephant population do simulate receptive oestrus behaviours, and this false oestrus occurs disproportionately in the presence of naïve female kin who are observed coming into oestrus for the first time. We compare several alternative hypotheses for the occurrence of this simulation: 1) false oestrus has no functional purpose (e.g., it merely results from abnormal hormonal changes); 2) false oestrus increases the reproductive success of the simulating female, by inducing sexual receptivity; and 3) false oestrus increases the inclusive fitness of the simulating female, either by increasing the access of related females to suitable males, or by encouraging appropriate oestrus behaviours from female relatives who are not responding correctly to males. Although the observed data do not fully conform to the predictions of any of these hypotheses, we rule out the first two, and tentatively suggest that parous females most likely exhibit false oestrus behaviours in order to demonstrate to naïve relatives at whom to direct their behaviour. 2010-04-01T00:00:00Z Bates, Lucy Handford, R Lee, P C Njiraini, N Poole, J H Sayialel, K Sayialel, S Moss, C J Byrne, Richard William Female African elephants signal oestrus via chemicals in their urine, but they also exhibit characteristic changes to their posture, gait and behaviour when sexually receptive. Free-ranging females visually signal receptivity by holding their heads and tails high, walking with an exaggerated gait, and displaying increased tactile behaviour towards males. Parous females occasionally exhibit these visual signals at times when they are thought not to be cycling and without attracting interest from musth males. Using demographic and behavioural records spanning a continuous 28-year period, we investigated the occurrence of this “simulated” oestrus behaviour. We show that parous females in the Amboseli elephant population do simulate receptive oestrus behaviours, and this false oestrus occurs disproportionately in the presence of naïve female kin who are observed coming into oestrus for the first time. We compare several alternative hypotheses for the occurrence of this simulation: 1) false oestrus has no functional purpose (e.g., it merely results from abnormal hormonal changes); 2) false oestrus increases the reproductive success of the simulating female, by inducing sexual receptivity; and 3) false oestrus increases the inclusive fitness of the simulating female, either by increasing the access of related females to suitable males, or by encouraging appropriate oestrus behaviours from female relatives who are not responding correctly to males. Although the observed data do not fully conform to the predictions of any of these hypotheses, we rule out the first two, and tentatively suggest that parous females most likely exhibit false oestrus behaviours in order to demonstrate to naïve relatives at whom to direct their behaviour. http://hdl.handle.net/10023/1050 Abstract: Excitotoxic lesions of posterior, but not anterior pedunculopontine tegmental nucleus (PPTg) change nicotine self-administration, consistent with the belief that the anterior PPTg (aPPTg) projects to substantia nigra pars compacta (SNC) and posterior PPTg (pPPTg) to the ventral tegmental area (VTA). The VTA is a likely site both of nicotine's reinforcing effect as well as its actions on locomotion. We hypothesized that pPPTg, but not aPPTg lesions, would alter locomotion in response to repeated nicotine administration by virtue of the fact that pPPTg appears to be more closely related to the VTA than is the aPPTg. Following excitotoxic lesions of aPPTg or pPPTg, rats were habituated to experimental procedures. Repeated (seven of each) nicotine (0.4 mg/kg) and saline injections were given following an on-off procedure. Measurement of spontaneous locomotion during habituation showed that aPPTg but not pPPTg lesioned rats were hypoactive relative to controls. Following nicotine, control rats showed locomotor depression for the first 2 days of treatment followed by enhanced locomotion relative to activity following saline treatment. Rats with aPPTg lesions showed a similar pattern, but the pPPTg lesioned rats showed no locomotor depression following nicotine treatment. These data confirm the role of the pPPTg in nicotine's behavioural effects-including the development of sensitization-and demonstrate for the first time that excitotoxic lesions of the aPPTg but not pPPTg generate a deficit in baseline activity. The finding that anterior but not posterior PPTg affects motor activity has significance for developing therapeutic strategies for Parkinsonism using deep brain stimulation aimed here. 2008-09-01T00:00:00Z Alderson, Helen L. Latimer, Mary P. Winn, Philip Excitotoxic lesions of posterior, but not anterior pedunculopontine tegmental nucleus (PPTg) change nicotine self-administration, consistent with the belief that the anterior PPTg (aPPTg) projects to substantia nigra pars compacta (SNC) and posterior PPTg (pPPTg) to the ventral tegmental area (VTA). The VTA is a likely site both of nicotine's reinforcing effect as well as its actions on locomotion. We hypothesized that pPPTg, but not aPPTg lesions, would alter locomotion in response to repeated nicotine administration by virtue of the fact that pPPTg appears to be more closely related to the VTA than is the aPPTg. Following excitotoxic lesions of aPPTg or pPPTg, rats were habituated to experimental procedures. Repeated (seven of each) nicotine (0.4 mg/kg) and saline injections were given following an on-off procedure. Measurement of spontaneous locomotion during habituation showed that aPPTg but not pPPTg lesioned rats were hypoactive relative to controls. Following nicotine, control rats showed locomotor depression for the first 2 days of treatment followed by enhanced locomotion relative to activity following saline treatment. Rats with aPPTg lesions showed a similar pattern, but the pPPTg lesioned rats showed no locomotor depression following nicotine treatment. These data confirm the role of the pPPTg in nicotine's behavioural effects-including the development of sensitization-and demonstrate for the first time that excitotoxic lesions of the aPPTg but not pPPTg generate a deficit in baseline activity. The finding that anterior but not posterior PPTg affects motor activity has significance for developing therapeutic strategies for Parkinsonism using deep brain stimulation aimed here. http://hdl.handle.net/10023/1014 Abstract: In economic games the facial attributes of counterparts bias decisions to trust and decisions to enter play. We report research supporting hypotheses that trust and reciprocation decisions in trust games are biased by mechanisms of sexual selection. Hypotheses that trust game behaviour is modulated by inter-sexual competition were supported. 1) Attractive individuals elicit more cooperation. 2) Male participants display trust and reciprocation toward attractive female counterparts in excess of perceived trustworthiness (and this display is modulated by male self-reported physical dominance). 3) Female participants appear to respond to male trust as a signal of sexual interest and are therefore more likely to exploit the trust of attractive males. 4) In explicitly dating contexts females are more likely to prefer attractive males to pay for the meal. These results indicate that participants are biased by mate choice and mating display considerations while playing economic games in the lab. Hypotheses that trust game behaviour is modulated by intra-sexual competition for resources were also somewhat supported. 1) Male participants reporting an ability to win fights with same-sex peers are more exploitative of other males. 2) Cues to current circulating testosterone level in counterpart’s faces are less trusted but elicit more reciprocation. 3) The male sexually dimorphic trait facial width-to-height ratio (a trait which is related to both aggression and dominance) is related to an increased proportion of decisions to exploit others in the trust game while also being used by others as a cue to untrustworthiness. We conclude that trusting and trustworthy behaviour in both sexes is biased by mating market considerations predicted by intra- and inter-sexual selection. 2010-06-23T00:00:00Z Stirrat, Michael In economic games the facial attributes of counterparts bias decisions to trust and decisions to enter play. We report research supporting hypotheses that trust and reciprocation decisions in trust games are biased by mechanisms of sexual selection. Hypotheses that trust game behaviour is modulated by inter-sexual competition were supported. 1) Attractive individuals elicit more cooperation. 2) Male participants display trust and reciprocation toward attractive female counterparts in excess of perceived trustworthiness (and this display is modulated by male self-reported physical dominance). 3) Female participants appear to respond to male trust as a signal of sexual interest and are therefore more likely to exploit the trust of attractive males. 4) In explicitly dating contexts females are more likely to prefer attractive males to pay for the meal. These results indicate that participants are biased by mate choice and mating display considerations while playing economic games in the lab. Hypotheses that trust game behaviour is modulated by intra-sexual competition for resources were also somewhat supported. 1) Male participants reporting an ability to win fights with same-sex peers are more exploitative of other males. 2) Cues to current circulating testosterone level in counterpart’s faces are less trusted but elicit more reciprocation. 3) The male sexually dimorphic trait facial width-to-height ratio (a trait which is related to both aggression and dominance) is related to an increased proportion of decisions to exploit others in the trust game while also being used by others as a cue to untrustworthiness. We conclude that trusting and trustworthy behaviour in both sexes is biased by mating market considerations predicted by intra- and inter-sexual selection. http://hdl.handle.net/10023/988 Abstract: GABA is the main inhibitory neurotransmitter of the central nervous system. GABA[subscript A]Rs are multimeric transmembrane receptors, which are composed of 5 subunits. It is known that there are 19 subunits that can make up the GABA[subscript A]Rs, allowing for a vast array of receptor subtypes. In addition to the GABA binding site GABA[subscript A]Rs have distinct allosteric binding sites for benzodiazepines, barbiturates, ethanol, certain general anaesthetics and neuroactive steroids. The molecular heterogeneity of the GABA[subscript A]R is accompanied by distinct pharmacological profiles of the different receptor subtypes. The advance of transgenic mouse models has allowed the functional significance of this heterogeneity to be studied in vivo. Therefore, this thesis utilises a variety of transgenic mouse models carrying either mutations or deletions of certain subunits to study the functional significance of the receptor heterogeneity. Mice lacking the α1 subunit (α1[superscript(-/-)]), carrying a point mutation of the α1 subunit (α1H101R), and mice lacking the δ subunit (δ[superscript(-/-)]) have been utilised to investigate the role of these subunits in the sedative actions of benzodiazepines and the GABA[subscript A]R agonist THIP. Although there are limitations to the interpretation of these results due genetic background of the α1[superscript(-/-)] and α1H101R, experiments suggest that the α1H101R mutation is not behaviourally silent as previously suggested and provide further evidence that the α1 subunit mediates the sedative properties of benzodiazepines. These experiments also reveal that the extrasynaptic δ containing receptors are responsible for mediating the sedative effects of THIP, and these findings combined with evidence from collaborators, implicates the thalamus as an anatomical mediator of these effects. An investigation of the putative cognitive enhancing effects of THIP using an attentional set-shifting task for mice suggested that pre-treatment with THIP reduces the number of errors to reach criterion. δ[superscript(-/-)] mice could not be trained to perform the task, therefore further behavioural investigation of these mice was performed, which suggested a heightened level of anxiety and reduced motivation for a food reward. This thesis has furthered our understanding of the functional role of GABA[subscript A]R subtypes. With the advance in genetic manipulations that allow for regionally selective mutations of the receptor the anatomical structures involved in these functions can be identified. 2010-06-23T00:00:00Z Foister, Nicola GABA is the main inhibitory neurotransmitter of the central nervous system. GABA[subscript A]Rs are multimeric transmembrane receptors, which are composed of 5 subunits. It is known that there are 19 subunits that can make up the GABA[subscript A]Rs, allowing for a vast array of receptor subtypes. In addition to the GABA binding site GABA[subscript A]Rs have distinct allosteric binding sites for benzodiazepines, barbiturates, ethanol, certain general anaesthetics and neuroactive steroids. The molecular heterogeneity of the GABA[subscript A]R is accompanied by distinct pharmacological profiles of the different receptor subtypes. The advance of transgenic mouse models has allowed the functional significance of this heterogeneity to be studied in vivo. Therefore, this thesis utilises a variety of transgenic mouse models carrying either mutations or deletions of certain subunits to study the functional significance of the receptor heterogeneity. Mice lacking the α1 subunit (α1[superscript(-/-)]), carrying a point mutation of the α1 subunit (α1H101R), and mice lacking the δ subunit (δ[superscript(-/-)]) have been utilised to investigate the role of these subunits in the sedative actions of benzodiazepines and the GABA[subscript A]R agonist THIP. Although there are limitations to the interpretation of these results due genetic background of the α1[superscript(-/-)] and α1H101R, experiments suggest that the α1H101R mutation is not behaviourally silent as previously suggested and provide further evidence that the α1 subunit mediates the sedative properties of benzodiazepines. These experiments also reveal that the extrasynaptic δ containing receptors are responsible for mediating the sedative effects of THIP, and these findings combined with evidence from collaborators, implicates the thalamus as an anatomical mediator of these effects. An investigation of the putative cognitive enhancing effects of THIP using an attentional set-shifting task for mice suggested that pre-treatment with THIP reduces the number of errors to reach criterion. δ[superscript(-/-)] mice could not be trained to perform the task, therefore further behavioural investigation of these mice was performed, which suggested a heightened level of anxiety and reduced motivation for a food reward. This thesis has furthered our understanding of the functional role of GABA[subscript A]R subtypes. With the advance in genetic manipulations that allow for regionally selective mutations of the receptor the anatomical structures involved in these functions can be identified. http://hdl.handle.net/10023/964 Abstract: Tool-use by chimpanzees has attracted disproportionate attention among primatologists, because of an understandable wish to understand the evolutionary origins of hominin tool use. In archaeology and paleoanthropology, a focus on made-objects is inevitable: there is nothing else to study. However, it is evidently object-directed manual skills, enabling the objects to be made, that are critical in understanding the evolutionary origins of stone-tool manufacture. In this chapter I review object-directed manual skills in living great apes, making comparison where possible with hominin abilities that can be inferred from the archaeological record. To this end, ‘translations’ of terminology between the research traditions are offered. Much of the evidence comes from observation of apes gathering plants that present physical problems for handling and consumption, in addition to the more patchy data from tool use in captivity and the field. The living great apes, like ourselves, build up novel hierarchical structures involving regular sequences of elementary actions, showing co-ordinated manual role differentiation, in modular organizations with the option of iterating subroutines. Further, great apes appear able to use imitation of skilled practitioners as one source of information for this process, implying some ability to ‘see’ below the surface level of action and understand the motor planning of other individual; however, that process does not necessarily involve understanding cause-and-effect or the intentions of other individuals. Finally I consider whether a living non-human ape could effectively knap stone, and if not, what competence is lacking. 2005-01-01T00:00:00Z Byrne, RW Tool-use by chimpanzees has attracted disproportionate attention among primatologists, because of an understandable wish to understand the evolutionary origins of hominin tool use. In archaeology and paleoanthropology, a focus on made-objects is inevitable: there is nothing else to study. However, it is evidently object-directed manual skills, enabling the objects to be made, that are critical in understanding the evolutionary origins of stone-tool manufacture. In this chapter I review object-directed manual skills in living great apes, making comparison where possible with hominin abilities that can be inferred from the archaeological record. To this end, ‘translations’ of terminology between the research traditions are offered. Much of the evidence comes from observation of apes gathering plants that present physical problems for handling and consumption, in addition to the more patchy data from tool use in captivity and the field. The living great apes, like ourselves, build up novel hierarchical structures involving regular sequences of elementary actions, showing co-ordinated manual role differentiation, in modular organizations with the option of iterating subroutines. Further, great apes appear able to use imitation of skilled practitioners as one source of information for this process, implying some ability to ‘see’ below the surface level of action and understand the motor planning of other individual; however, that process does not necessarily involve understanding cause-and-effect or the intentions of other individuals. Finally I consider whether a living non-human ape could effectively knap stone, and if not, what competence is lacking. http://hdl.handle.net/10023/943 Abstract: Tool use is an important aspect of being human that has assumed a central place in accounts of the evolutionary origins of human intelligence. This has inevitably focused a spotlight on any signs of tool use or manufacture in great apes and other non-human animals, to the relative neglect of skills that do not involve tools. The aim of this chapter is to explore whether this emphasis is appropriate. Could it be that we may learn as much about the origin of human intelligence from skilled manual behaviour in general? Suppose we take this broader view, accepting evidence from all manifestations of manual skill, what can we learn of the mental capacities of the great apes and ourselves? My own ultimate purpose is to use comparative evidence from living species to reconstruct the evolutionary history of the many cognitive traits that came together to make human psychology. The cognition of great apes is the obvious starting point, to trace the more primitive (i.e. ancient) cognitive aptitudes that are still important to us today. In this chapter, I focus on great ape cognition as it is expressed in manual skills, based on cognitive aspects of tool use and manufacture considered significant in the human evolutionary lineage. 2004-01-01T00:00:00Z Byrne, RW Tool use is an important aspect of being human that has assumed a central place in accounts of the evolutionary origins of human intelligence. This has inevitably focused a spotlight on any signs of tool use or manufacture in great apes and other non-human animals, to the relative neglect of skills that do not involve tools. The aim of this chapter is to explore whether this emphasis is appropriate. Could it be that we may learn as much about the origin of human intelligence from skilled manual behaviour in general? Suppose we take this broader view, accepting evidence from all manifestations of manual skill, what can we learn of the mental capacities of the great apes and ourselves? My own ultimate purpose is to use comparative evidence from living species to reconstruct the evolutionary history of the many cognitive traits that came together to make human psychology. The cognition of great apes is the obvious starting point, to trace the more primitive (i.e. ancient) cognitive aptitudes that are still important to us today. In this chapter, I focus on great ape cognition as it is expressed in manual skills, based on cognitive aspects of tool use and manufacture considered significant in the human evolutionary lineage. http://hdl.handle.net/10023/934 Abstract: This thesis examined how international students experience life in the UK and, in particular, how these students respond to experiences with discrimination and social exclusion. Specifically, we drew on the rejection-identification model (Branscombe et al., 1999) in order to examine the impact of minority group identification as a coping strategy against perceptions of discrimination. Despite the number of studies supporting the rejection-identification model (e.g. Schmitt et al., 2002, Schmitt et al., 2003), discrepant findings were found in other research (e.g. McCoy & Major, 2003; Eccleston & Major, 2006). In order to solve these inconsistencies we proposed to extend this model in two important ways. Firstly, building on important work on the multidimensionality of social identification (e.g. Cameron & Lalonde, 2001; Ellemers et al., 1999; Jackson, 2002), we argued that a multidimensional perspective of the rejection-identification model is fundamental given that different dimensions of social identification (i.e. ingroup affect, centrality, and ingroup ties) have different effects on psychological well-being. Secondly, we hypothesised that the protective effect of the different dimensions of social identification depended upon individual preferences, beliefs and behaviours towards own and host group (i.e. acculturation strategies). These two extensions to the rejection-identification model were tested longitudinally with a sample of 160 international students. Results indicated that none of the dimensions of social identification serve to protect students from the harmful effects of discrimination. Indeed, support was found for the argument that it is important to investigate possible moderators of the rejection-identification relationship. Our results also indicated that when international students perceive discrimination, a separation strategy allows them to maintain ingroup affect, and in this way protect their self-esteem. Integration, marginalisation, and assimilation strategies were associated with lower ingroup affect leaving these students without a successful strategy to cope with discrimination. Although the aim of this thesis was to examine the experiences of international students, in Chapter 7 we replicated our previous model with a sample of Polish immigrants (N = 66) in order to test whether our results could be generalised to other minority groups. Results supported the previous findings with international students. Finally, the discussion of this thesis focused on the importance of taking into account individual acculturation strategies in order to understand the relation between perceived discrimination, minority group identification, and well-being. We also focused on how the knowledge generated by this research may support international students. 2010-06-23T00:00:00Z Ramos, Miguel R. This thesis examined how international students experience life in the UK and, in particular, how these students respond to experiences with discrimination and social exclusion. Specifically, we drew on the rejection-identification model (Branscombe et al., 1999) in order to examine the impact of minority group identification as a coping strategy against perceptions of discrimination. Despite the number of studies supporting the rejection-identification model (e.g. Schmitt et al., 2002, Schmitt et al., 2003), discrepant findings were found in other research (e.g. McCoy & Major, 2003; Eccleston & Major, 2006). In order to solve these inconsistencies we proposed to extend this model in two important ways. Firstly, building on important work on the multidimensionality of social identification (e.g. Cameron & Lalonde, 2001; Ellemers et al., 1999; Jackson, 2002), we argued that a multidimensional perspective of the rejection-identification model is fundamental given that different dimensions of social identification (i.e. ingroup affect, centrality, and ingroup ties) have different effects on psychological well-being. Secondly, we hypothesised that the protective effect of the different dimensions of social identification depended upon individual preferences, beliefs and behaviours towards own and host group (i.e. acculturation strategies). These two extensions to the rejection-identification model were tested longitudinally with a sample of 160 international students. Results indicated that none of the dimensions of social identification serve to protect students from the harmful effects of discrimination. Indeed, support was found for the argument that it is important to investigate possible moderators of the rejection-identification relationship. Our results also indicated that when international students perceive discrimination, a separation strategy allows them to maintain ingroup affect, and in this way protect their self-esteem. Integration, marginalisation, and assimilation strategies were associated with lower ingroup affect leaving these students without a successful strategy to cope with discrimination. Although the aim of this thesis was to examine the experiences of international students, in Chapter 7 we replicated our previous model with a sample of Polish immigrants (N = 66) in order to test whether our results could be generalised to other minority groups. Results supported the previous findings with international students. Finally, the discussion of this thesis focused on the importance of taking into account individual acculturation strategies in order to understand the relation between perceived discrimination, minority group identification, and well-being. We also focused on how the knowledge generated by this research may support international students. http://hdl.handle.net/10023/908 Abstract: By investigating the cognitive capacities of non-human primates, we can begin to understand the cognitive capacities of the evolutionary ancestors we share with these species. While there is a great deal of research exploring the socio-cognitive abilities of simian primates, prosimians have not been sufficiently studied. Without data from these species, our knowledge about the evolution of the primate mind is limited to the common ancestor shared between simian primates only, precluding understanding of the phylogenetic origins of certain phenomena. I explored the socio-cognitive capacities of lemurs, a type of prosimian primate. I studied several areas of social cognition related to social referencing, defined as the ability to use and seek out social information when appraising objects or events. As social referencing is a popular subject in both human developmental and non-human primate literature, I aimed to determine how prosimians’ capacities compare. My research was conducted with captive lemurs of three species: Eulemur fulvus fulvus, Eulemur macaco macaco, and Eulemur fulvus rufus. I found that lemurs use social cues regarding food palatability to modify their own feeding behaviour and that they visually attend to conspecifics differently when presented with novel, as compared to familiar, foods. Lemurs also visually referred to a human experimenter’s face when presented with an anomalous interaction and went on to engage in gaze alternation. Lemurs failed to use information about the experimenter’s attentional state, however, when modifying their use of a trained gesture. Finally, I found that lemurs are able to visually co-orient with conspecifics, correctly prioritising information from the head over that from the body, and that they go on to use conspecific gaze to locate hidden resources. These results show that lemurs are more cognitively advanced than previously thought and the origins of some social referencing skills may be phylogenetically older than previously hypothesised. 2010-06-01T00:00:00Z Ruiz, April M. By investigating the cognitive capacities of non-human primates, we can begin to understand the cognitive capacities of the evolutionary ancestors we share with these species. While there is a great deal of research exploring the socio-cognitive abilities of simian primates, prosimians have not been sufficiently studied. Without data from these species, our knowledge about the evolution of the primate mind is limited to the common ancestor shared between simian primates only, precluding understanding of the phylogenetic origins of certain phenomena. I explored the socio-cognitive capacities of lemurs, a type of prosimian primate. I studied several areas of social cognition related to social referencing, defined as the ability to use and seek out social information when appraising objects or events. As social referencing is a popular subject in both human developmental and non-human primate literature, I aimed to determine how prosimians’ capacities compare. My research was conducted with captive lemurs of three species: Eulemur fulvus fulvus, Eulemur macaco macaco, and Eulemur fulvus rufus. I found that lemurs use social cues regarding food palatability to modify their own feeding behaviour and that they visually attend to conspecifics differently when presented with novel, as compared to familiar, foods. Lemurs also visually referred to a human experimenter’s face when presented with an anomalous interaction and went on to engage in gaze alternation. Lemurs failed to use information about the experimenter’s attentional state, however, when modifying their use of a trained gesture. Finally, I found that lemurs are able to visually co-orient with conspecifics, correctly prioritising information from the head over that from the body, and that they go on to use conspecific gaze to locate hidden resources. These results show that lemurs are more cognitively advanced than previously thought and the origins of some social referencing skills may be phylogenetically older than previously hypothesised. http://hdl.handle.net/10023/886 Abstract: Reinforcement learning occurs when organisms adapt the propensities of given behaviours on the basis of associations with reward and punishment. Currently, reinforcement learning models have been validated in minimalist environments in which only 1-2 environmental stimuli are present as possible predictors of reward. The exception to this is two studies in which the responses of the dopamine system to configurations of multiple stimuli were investigated, however, in both cases the stimuli were presented simultaneously rather than in a sequence. Therefore, we set out to understand how current models of reinforcement learning would respond under more complex conditions in which sequences of events are predictors of reward. In the two experimental chapters of this thesis, we attempted to understand whether midbrain dopaminergic neurons would respond to occasion setters (Chapter 3), and to the overexpectation effect (Chapter 4). In addition, we ran simulations of the behavioural paradigms using temporal difference models of reinforcement learning (Chapter 2) and compared the predictions of the model with the behavioural and neurophysiological data. In Chapter 3, by performing single-neuron recording from VTA and SNpc dopaminergic cells, we demonstrated that our population of neurons were most responsive to the latest predictor of reward, the conditioned stimulus (CS) and not the earliest, the occasion setter (the OS). This is in stark contrast with the predictions of the model (Chapter 2), where the greatest response is seen at the OS onset. We also showed at a neural level that there was only a weak enhancement of the response to the discriminative stimulus (SD) when this was preceded by the OS. On the other hand, at a behavioural level, bar pressing was greatest when the SD was preceded by the OS, demonstrating that rats could use the information provided by the OS, but that dopamine was not controlling the conditioned response. In Chapter 4, our population of dopaminergic neurons showed that they would preferentially respond to only one of the two conditioned stimuli (CSA, CSB) in the overexpectation paradigm. The predictions of the model (Chapter 2) suggested that when the two stimuli would be presented in compound, there would be an inhibitory response if the reward magnitude was kept constant and an excitatory response if the reward magnitude was doubled. The lack of neural firing to one of the two conditioned stimuli, however, does not make for easy interpretation of the data. Perhaps, one of the conditioned stimuli acted as if it were overshadowing the other, resulting in no response to the second CS. Interestingly, at a behavioural level, we did not see increased licking frequency to the compound stimuli presentation, a result that is somewhat at odds with the previous literature. Overall, the results of our experimental chapters suggest that the role that midbrain dopaminergic neurons play in reinforcement learning is more complex than that envisaged by previous investigations. 2010-06-01T00:00:00Z Aquili, Luca Reinforcement learning occurs when organisms adapt the propensities of given behaviours on the basis of associations with reward and punishment. Currently, reinforcement learning models have been validated in minimalist environments in which only 1-2 environmental stimuli are present as possible predictors of reward. The exception to this is two studies in which the responses of the dopamine system to configurations of multiple stimuli were investigated, however, in both cases the stimuli were presented simultaneously rather than in a sequence. Therefore, we set out to understand how current models of reinforcement learning would respond under more complex conditions in which sequences of events are predictors of reward. In the two experimental chapters of this thesis, we attempted to understand whether midbrain dopaminergic neurons would respond to occasion setters (Chapter 3), and to the overexpectation effect (Chapter 4). In addition, we ran simulations of the behavioural paradigms using temporal difference models of reinforcement learning (Chapter 2) and compared the predictions of the model with the behavioural and neurophysiological data. In Chapter 3, by performing single-neuron recording from VTA and SNpc dopaminergic cells, we demonstrated that our population of neurons were most responsive to the latest predictor of reward, the conditioned stimulus (CS) and not the earliest, the occasion setter (the OS). This is in stark contrast with the predictions of the model (Chapter 2), where the greatest response is seen at the OS onset. We also showed at a neural level that there was only a weak enhancement of the response to the discriminative stimulus (SD) when this was preceded by the OS. On the other hand, at a behavioural level, bar pressing was greatest when the SD was preceded by the OS, demonstrating that rats could use the information provided by the OS, but that dopamine was not controlling the conditioned response. In Chapter 4, our population of dopaminergic neurons showed that they would preferentially respond to only one of the two conditioned stimuli (CSA, CSB) in the overexpectation paradigm. The predictions of the model (Chapter 2) suggested that when the two stimuli would be presented in compound, there would be an inhibitory response if the reward magnitude was kept constant and an excitatory response if the reward magnitude was doubled. The lack of neural firing to one of the two conditioned stimuli, however, does not make for easy interpretation of the data. Perhaps, one of the conditioned stimuli acted as if it were overshadowing the other, resulting in no response to the second CS. Interestingly, at a behavioural level, we did not see increased licking frequency to the compound stimuli presentation, a result that is somewhat at odds with the previous literature. Overall, the results of our experimental chapters suggest that the role that midbrain dopaminergic neurons play in reinforcement learning is more complex than that envisaged by previous investigations. http://hdl.handle.net/10023/844 Abstract: The main aim of this thesis was to explore the maintenance of personhood and self-image in dementia by way of facilitating collaborative communication between people with dementia and their caregivers/interaction partners. As such, the roles of the person with dementia and the interaction partner were examined in each study within the realms of the ‘Collaborative Personhood Model’. Findings of the first study highlighted strategies used by people with mild to severe dementia to maintain social interactions, to save-face and to maintain and project a sense of self-image in a reminiscence situation. The impact of introducing a family member as the interaction partner in a similar reminiscence-based situation using personal photographs was then explored. The findings of this study indicated that the personal nature of the photographs can create conflict between the person with dementia and her family member. Crucially, these studies illuminated the supportive role that the communication partner must adopt in order to successfully facilitate people with dementia to maximise their retained communication skills. Communication and sense of self was then examined in an individual with very severe dementia with some retained speech. The findings of this study illuminated the potential of imitation in communicating with people at this stage of the illness. These findings were then built upon by exploring the use of Intensive Interaction (II) in a person with very advanced dementia with no retained speech. Findings of this study indicated retained awareness of self and functional communication skills at very late stages of dementia. Finally, this study was expanded using a modified version of II (Adaptive Interaction) in a small group of individuals with very severe dementia with very little or no retained speech. These findings indicated an unprecedented desire and ability to communicate in people with such severe dementia. Taken as a whole, these studies highlighted the adaptive and collaborative role that the interaction partner must adopt in order to facilitate the maintenance of personhood and self-image in people with dementia. More specifically, the interaction partner must adjust to the communicative repertoire that is maintained at each stage of dementia and in each individual. The ‘Collaborative Personhood Model’ represents an attempt to explain how this might be achieved. 2009-01-01T00:00:00Z Ellis, Maggie P. The main aim of this thesis was to explore the maintenance of personhood and self-image in dementia by way of facilitating collaborative communication between people with dementia and their caregivers/interaction partners. As such, the roles of the person with dementia and the interaction partner were examined in each study within the realms of the ‘Collaborative Personhood Model’. Findings of the first study highlighted strategies used by people with mild to severe dementia to maintain social interactions, to save-face and to maintain and project a sense of self-image in a reminiscence situation. The impact of introducing a family member as the interaction partner in a similar reminiscence-based situation using personal photographs was then explored. The findings of this study indicated that the personal nature of the photographs can create conflict between the person with dementia and her family member. Crucially, these studies illuminated the supportive role that the communication partner must adopt in order to successfully facilitate people with dementia to maximise their retained communication skills. Communication and sense of self was then examined in an individual with very severe dementia with some retained speech. The findings of this study illuminated the potential of imitation in communicating with people at this stage of the illness. These findings were then built upon by exploring the use of Intensive Interaction (II) in a person with very advanced dementia with no retained speech. Findings of this study indicated retained awareness of self and functional communication skills at very late stages of dementia. Finally, this study was expanded using a modified version of II (Adaptive Interaction) in a small group of individuals with very severe dementia with very little or no retained speech. These findings indicated an unprecedented desire and ability to communicate in people with such severe dementia. Taken as a whole, these studies highlighted the adaptive and collaborative role that the interaction partner must adopt in order to facilitate the maintenance of personhood and self-image in people with dementia. More specifically, the interaction partner must adjust to the communicative repertoire that is maintained at each stage of dementia and in each individual. The ‘Collaborative Personhood Model’ represents an attempt to explain how this might be achieved. http://hdl.handle.net/10023/832 Abstract: Black-and-white colobus monkeys are renowned for their impressive vocal behaviour, but up to date there have been only very few systematic efforts to study this. These monkeys are able to produce loud and low-pitched roars that transmit over long distances, which has lead to the assumption that these calls function in inter-group spacing and male-male competition. The fact that the monkeys sometimes produce the same calls to predators as well, has not received much attention so far. This thesis presents a detailed description of the form and function of the anti-predator behaviour of one species of black-and-white colobus monkeys, the Guereza (Colobus guereza), with a specific focus on their alarm calling behaviour. A second aim was to determine the effects of predator experience on their anti-predator behaviour, with a specific focus on call comprehension and production. Data were collected from two populations of Guereza monkeys in the Budongo Forest Reserve, Uganda, that differ in predation pressures experienced by their main predators: leopards, eagles and chimpanzees. Results showed that Guerezas use a basic form of zoo-syntax in order to compose predator-specific call sequences that vary in the number of roaring phrases and snorts. These sequences are meaningful to recipients, at least at the level of the predator class, but there were also indications for additional levels of encoded information: Guerezas appear to have evolved a second system, based on acoustic variants of individual phrases, which allows them to narrow down the information content of call sequences, generating the potential to communicate highly specific information by using a mix of syntactic and semantic cues. The monkeys’ vocal behaviour was influenced by predator experience, but not strongly so. Monkeys without prior experience with leopards lacked some of the behavioural nuances seen in leopard-experienced monkeys, but they nevertheless responded appropriately to visual and acoustic leopard models, suggesting they had retained the basic capacities to recognise this predator type as relevant and dangerous. Results are discussed in light of the comparative approach to the study of human language evolution. Although human language is unique in a number of ways, for example through its use of complex syntax and intentional semantics, some animal communication systems have revealed similar features, and Guerezas, the first member of the colobine family to be studied in this respect, are no exception. The Guerezas’ alarm calling behaviour is complex and flexible, and these monkeys have provided another piece of empirical evidence that is directly relevant for the comparative approach to human language evolution. 2009-06-24T00:00:00Z Schel, Anne Marijke Black-and-white colobus monkeys are renowned for their impressive vocal behaviour, but up to date there have been only very few systematic efforts to study this. These monkeys are able to produce loud and low-pitched roars that transmit over long distances, which has lead to the assumption that these calls function in inter-group spacing and male-male competition. The fact that the monkeys sometimes produce the same calls to predators as well, has not received much attention so far. This thesis presents a detailed description of the form and function of the anti-predator behaviour of one species of black-and-white colobus monkeys, the Guereza (Colobus guereza), with a specific focus on their alarm calling behaviour. A second aim was to determine the effects of predator experience on their anti-predator behaviour, with a specific focus on call comprehension and production. Data were collected from two populations of Guereza monkeys in the Budongo Forest Reserve, Uganda, that differ in predation pressures experienced by their main predators: leopards, eagles and chimpanzees. Results showed that Guerezas use a basic form of zoo-syntax in order to compose predator-specific call sequences that vary in the number of roaring phrases and snorts. These sequences are meaningful to recipients, at least at the level of the predator class, but there were also indications for additional levels of encoded information: Guerezas appear to have evolved a second system, based on acoustic variants of individual phrases, which allows them to narrow down the information content of call sequences, generating the potential to communicate highly specific information by using a mix of syntactic and semantic cues. The monkeys’ vocal behaviour was influenced by predator experience, but not strongly so. Monkeys without prior experience with leopards lacked some of the behavioural nuances seen in leopard-experienced monkeys, but they nevertheless responded appropriately to visual and acoustic leopard models, suggesting they had retained the basic capacities to recognise this predator type as relevant and dangerous. Results are discussed in light of the comparative approach to the study of human language evolution. Although human language is unique in a number of ways, for example through its use of complex syntax and intentional semantics, some animal communication systems have revealed similar features, and Guerezas, the first member of the colobine family to be studied in this respect, are no exception. The Guerezas’ alarm calling behaviour is complex and flexible, and these monkeys have provided another piece of empirical evidence that is directly relevant for the comparative approach to human language evolution. http://hdl.handle.net/10023/774 Abstract: A growing body of behavioural data is beginning to show that, like their male counterparts, female chimpanzees can be competitive and aggressive, particularly when resources come under pressure. These observations are especially surprising because, for a long time, females were simply considered passive pawns of male social manoeuvrings. While we are beginning to understand the complexities surrounding female chimpanzee group living, exactly how females manage these social pressures is unclear. In this thesis I address this by focusing on female competition in wild chimpanzees and the importance of vocal counter-strategies. I examined two commonly produced female vocalisations: copulation calls and victim screams from chimpanzees (Pan troglodytes schweinfurthii) in the Budongo Forest, Uganda. My results regarding the production and acoustic structure of copulation calls suggests that these vocalisations play a crucial role in the lives of female chimpanzees, dissipating the risks associated with female competition. During aggression, chimpanzee females commonly produce victim screams and these calls have been shown to vary systematically with the severity of aggression experienced. A playback experiment showed that victim screams are meaningful to females and that listeners do not just respond to the acoustically most salient signals in their environment. Females may use this information to keep track of out-of-sight agonistic interactions and make appropriate social decisions regarding whether to avoid an ensuing attack. Taken together, I propose that vocalisations may represent important behavioural counter-strategies, enabling females to navigate successfully through their socially intricate world. 2009-01-01T00:00:00Z Townsend, Simon W. A growing body of behavioural data is beginning to show that, like their male counterparts, female chimpanzees can be competitive and aggressive, particularly when resources come under pressure. These observations are especially surprising because, for a long time, females were simply considered passive pawns of male social manoeuvrings. While we are beginning to understand the complexities surrounding female chimpanzee group living, exactly how females manage these social pressures is unclear. In this thesis I address this by focusing on female competition in wild chimpanzees and the importance of vocal counter-strategies. I examined two commonly produced female vocalisations: copulation calls and victim screams from chimpanzees (Pan troglodytes schweinfurthii) in the Budongo Forest, Uganda. My results regarding the production and acoustic structure of copulation calls suggests that these vocalisations play a crucial role in the lives of female chimpanzees, dissipating the risks associated with female competition. During aggression, chimpanzee females commonly produce victim screams and these calls have been shown to vary systematically with the severity of aggression experienced. A playback experiment showed that victim screams are meaningful to females and that listeners do not just respond to the acoustically most salient signals in their environment. Females may use this information to keep track of out-of-sight agonistic interactions and make appropriate social decisions regarding whether to avoid an ensuing attack. Taken together, I propose that vocalisations may represent important behavioural counter-strategies, enabling females to navigate successfully through their socially intricate world. http://hdl.handle.net/10023/753 Abstract: Many non-human animal species use colour to signal dominance, condition or reproductive status. These signals have not previously been noted in humans. This thesis investigates the effects of skin colouration and pigmentation on the apparent health of human faces. Section 2 showed that individuals with increased fruit and vegetable and carotenoid consumption have yellower skin (Study 1) due to increased carotenoid pigmentation in the skin (Study 2). In Section 3, participants enhanced the redness, yellowness and lightness of the skin portions of colour-calibrated facial photographs to optimise healthy appearance. This suggests roles for blood (red) and carotenoid/melanin (yellow) colouration in providing perceptible cues to health. The contrast between lips and facial skin colour was not found to affect the apparent health of the faces, except in the b* (yellowness) axis, where enhanced facial yellowness caused an apparent blue tint to the lips. In Section 4 participants enhanced empirically-derived oxygenated blood colour more than deoxygenated blood colour to optimise healthy appearance. In two-dimensional trials, when both blood colour axes could be manipulated simultaneously, deoxygenated blood colour was removed and replaced with oxygenated blood colour. Oxygenated blood colouration appears to drive the preference for redness in faces. In Section 5 participants increased carotenoid colour significantly more than they increased melanin colour in both single-axis and two-dimensional trials. Carotenoid colour appears to drive the preference for yellowness in faces. In a cross-cultural study (Section 6), preferences for red and yellow in faces were unaffected by face or participant ethnicity, while African participants lightened faces more than UK participants. A preference for more redness in East Asian faces was explained by this group’s lower initial redness. The thesis concludes that pigments that provide sexually-selected signals of quality in many non-human animal species – carotenoids and oxygenated blood - also provide perceptible cues to health in human faces. 2009-11-11T00:00:00Z Stephen, Ian D. Many non-human animal species use colour to signal dominance, condition or reproductive status. These signals have not previously been noted in humans. This thesis investigates the effects of skin colouration and pigmentation on the apparent health of human faces. Section 2 showed that individuals with increased fruit and vegetable and carotenoid consumption have yellower skin (Study 1) due to increased carotenoid pigmentation in the skin (Study 2). In Section 3, participants enhanced the redness, yellowness and lightness of the skin portions of colour-calibrated facial photographs to optimise healthy appearance. This suggests roles for blood (red) and carotenoid/melanin (yellow) colouration in providing perceptible cues to health. The contrast between lips and facial skin colour was not found to affect the apparent health of the faces, except in the b* (yellowness) axis, where enhanced facial yellowness caused an apparent blue tint to the lips. In Section 4 participants enhanced empirically-derived oxygenated blood colour more than deoxygenated blood colour to optimise healthy appearance. In two-dimensional trials, when both blood colour axes could be manipulated simultaneously, deoxygenated blood colour was removed and replaced with oxygenated blood colour. Oxygenated blood colouration appears to drive the preference for redness in faces. In Section 5 participants increased carotenoid colour significantly more than they increased melanin colour in both single-axis and two-dimensional trials. Carotenoid colour appears to drive the preference for yellowness in faces. In a cross-cultural study (Section 6), preferences for red and yellow in faces were unaffected by face or participant ethnicity, while African participants lightened faces more than UK participants. A preference for more redness in East Asian faces was explained by this group’s lower initial redness. The thesis concludes that pigments that provide sexually-selected signals of quality in many non-human animal species – carotenoids and oxygenated blood - also provide perceptible cues to health in human faces. http://hdl.handle.net/10023/745 Abstract: Culture involves the handing down of information, traditions, knowledge and skill, views and ideals from one individual to another and across generations by means of social transmission expressed in manufactured objects and behaviour. The evolution of cumulative culture, a human specific capacity, makes possible an inheritance system that is governed by the same Darwinian principles as biological evolution. Cumulative culture has made possible the build-up or ratcheting effect of knowledge and traditions that when put together allow for advanced technology, medicine, education and other highly advanced cognitive processes that characterise humans from non human animals. This dissertation dedicates the first chapter to review the literature pertaining to this topic; describing various types of social learning processes and methodological approaches that are used to query and broadly describe the process of culture in various animals. The following two chapters (2 and 3) present three experiments that provide methodical and systematic exploration of the social transmission process which occurs in chimpanzees; using 3 artificial foraging devices, the 3 studies systematically demonstrate that chimpanzees have the capacity to transmit culture from one individual to another and serially across neighbouring communities- providing laboratory evidence of behavioural variation analogous to that observed in the wild. Chapter 4 then goes on to describe an experiment that tests a number of hypothesised biases in cultural transmission. Looking specifically at social dynamics at play during the transmission of skill within ape groups - I systematically analyse the effects of directed social learning; focusing on kin and status based strategies that are characteristic of group living apes. Chapter 5 is an original, empirical and methodically comparative analysis of hierarchically organized behaviour in human children and chimpanzees using a hierarchically organized artificial fruit. The final chapter (6) discusses the findings of each of the five experiments and compares the results to findings at other captive and wild research sites. I then broaden the topic to explore how the findings relate to broad issues in literature and provide a framework for future research and for understanding the complex mechanisms of intelligent systems. 2009-06-24T00:00:00Z Spiteri, Anthony Culture involves the handing down of information, traditions, knowledge and skill, views and ideals from one individual to another and across generations by means of social transmission expressed in manufactured objects and behaviour. The evolution of cumulative culture, a human specific capacity, makes possible an inheritance system that is governed by the same Darwinian principles as biological evolution. Cumulative culture has made possible the build-up or ratcheting effect of knowledge and traditions that when put together allow for advanced technology, medicine, education and other highly advanced cognitive processes that characterise humans from non human animals. This dissertation dedicates the first chapter to review the literature pertaining to this topic; describing various types of social learning processes and methodological approaches that are used to query and broadly describe the process of culture in various animals. The following two chapters (2 and 3) present three experiments that provide methodical and systematic exploration of the social transmission process which occurs in chimpanzees; using 3 artificial foraging devices, the 3 studies systematically demonstrate that chimpanzees have the capacity to transmit culture from one individual to another and serially across neighbouring communities- providing laboratory evidence of behavioural variation analogous to that observed in the wild. Chapter 4 then goes on to describe an experiment that tests a number of hypothesised biases in cultural transmission. Looking specifically at social dynamics at play during the transmission of skill within ape groups - I systematically analyse the effects of directed social learning; focusing on kin and status based strategies that are characteristic of group living apes. Chapter 5 is an original, empirical and methodically comparative analysis of hierarchically organized behaviour in human children and chimpanzees using a hierarchically organized artificial fruit. The final chapter (6) discusses the findings of each of the five experiments and compares the results to findings at other captive and wild research sites. I then broaden the topic to explore how the findings relate to broad issues in literature and provide a framework for future research and for understanding the complex mechanisms of intelligent systems. http://hdl.handle.net/10023/740 Abstract: The research aims of this thesis are to experimentally investigate how behaviours spread socially, and what factors contribute to the development of group-wide social traditions in capuchins (Cebus apella). Given the apparent convergent evolution between such monkeys and great apes, capuchin traditions are of great interest anthropologically and for a biological and psychological understanding of culture. Several studies have investigated social learning in capuchins, but few have made headway into understanding how it supports the development of traditions either in the wild or in captivity. By experimentally introducing novel foraging behaviours into several captive groups, the studies included in this thesis simulate the development of foraging behaviours so that their spread can be studied from various viewpoints. Five experiments are presented investigating: (1) the chained transmission of foraging behaviours, (2) the role of social facilitation on the rate of individual learning, (3) the fidelity of learning from localised stimulus enhancement & object-movement re-enactment, (4) the quality of individual relationships in the social transmission of novel foraging techniques, and (5) the open diffusion of group-specific foraging behaviours in capuchin monkeys. Together, these experiments explore how traditions may develop, ranging from individual learning to how behaviour patterns may spread socially based on social ties within the group. 2009-06-24T00:00:00Z Dindo, Marietta The research aims of this thesis are to experimentally investigate how behaviours spread socially, and what factors contribute to the development of group-wide social traditions in capuchins (Cebus apella). Given the apparent convergent evolution between such monkeys and great apes, capuchin traditions are of great interest anthropologically and for a biological and psychological understanding of culture. Several studies have investigated social learning in capuchins, but few have made headway into understanding how it supports the development of traditions either in the wild or in captivity. By experimentally introducing novel foraging behaviours into several captive groups, the studies included in this thesis simulate the development of foraging behaviours so that their spread can be studied from various viewpoints. Five experiments are presented investigating: (1) the chained transmission of foraging behaviours, (2) the role of social facilitation on the rate of individual learning, (3) the fidelity of learning from localised stimulus enhancement & object-movement re-enactment, (4) the quality of individual relationships in the social transmission of novel foraging techniques, and (5) the open diffusion of group-specific foraging behaviours in capuchin monkeys. Together, these experiments explore how traditions may develop, ranging from individual learning to how behaviour patterns may spread socially based on social ties within the group. http://hdl.handle.net/10023/706 Abstract: Pubertal timing is a human life history variable representing a trade-off between early reproduction and continued growth. Dominance is an important feature to male mate value. These two variables should have far-reaching effects on adult male life. Chapter 1 reviews evolution, r/K selection and life history theory to derive hypotheses concerning variation in male mating strategy. Chapters 2-4 investigate the effects of pubertal timing and dominance on mating strategy using sociosexual orientation and preferences for faces and mate characteristics. Both early puberty and high dominance associate with unrestricted sociosexuality (increased interest in casual sex) as predicted. Dominance is shown to relate to preferences for cues of sociosexuality but not femininity, while pubertal timing relates to neither facial characteristic. Earlier and later developing men do not differ in their mate characteristic preferences, while dominant men exhibit enhanced female-typical mate preferences counter to predictions. A dominance-dependent, dual, male mating strategy is proposed to account for results. Chapter 5 introduces sensitivity to putative human pheromones as an indicator of mating strategy. Dominant men are found to be more sensitive to and more averse to a putative female pheromone. Pubertal timing has no effect on sensitivity. Results are interpreted in terms of dominant male avoidance of infertile matings. Chapter 6 finds that early puberty associates with facial masculinity, attractiveness and apparent age. Chapter 7 offers a hormonal underpinning of effects related to pubertal timing, showing that early development associates with higher levels of testosterone in men. Chapter 8 uses digit length ratios to show that early developing men may have been exposed to greater levels of uterine testosterone, suggesting prenatal influences on male pubertal timing. Chapter 9 shows dominance associates with bodily, vocal and general attractiveness but not facial attractiveness. Chapter 10 reports that dominance associates with high levels of the stress hormone cortisol, suggesting costs of high dominance. Chapter 11 shows early pubertal timing relates to the visual appearance of skin, perhaps because of lower sebum production among early developing men, leading to them having darker, less reflective skin. This may reflect accelerated ageing of early developing males, potentially representing a cost to longevity. 2008-01-01T00:00:00Z Lawson, Jamie F. Pubertal timing is a human life history variable representing a trade-off between early reproduction and continued growth. Dominance is an important feature to male mate value. These two variables should have far-reaching effects on adult male life. Chapter 1 reviews evolution, r/K selection and life history theory to derive hypotheses concerning variation in male mating strategy. Chapters 2-4 investigate the effects of pubertal timing and dominance on mating strategy using sociosexual orientation and preferences for faces and mate characteristics. Both early puberty and high dominance associate with unrestricted sociosexuality (increased interest in casual sex) as predicted. Dominance is shown to relate to preferences for cues of sociosexuality but not femininity, while pubertal timing relates to neither facial characteristic. Earlier and later developing men do not differ in their mate characteristic preferences, while dominant men exhibit enhanced female-typical mate preferences counter to predictions. A dominance-dependent, dual, male mating strategy is proposed to account for results. Chapter 5 introduces sensitivity to putative human pheromones as an indicator of mating strategy. Dominant men are found to be more sensitive to and more averse to a putative female pheromone. Pubertal timing has no effect on sensitivity. Results are interpreted in terms of dominant male avoidance of infertile matings. Chapter 6 finds that early puberty associates with facial masculinity, attractiveness and apparent age. Chapter 7 offers a hormonal underpinning of effects related to pubertal timing, showing that early development associates with higher levels of testosterone in men. Chapter 8 uses digit length ratios to show that early developing men may have been exposed to greater levels of uterine testosterone, suggesting prenatal influences on male pubertal timing. Chapter 9 shows dominance associates with bodily, vocal and general attractiveness but not facial attractiveness. Chapter 10 reports that dominance associates with high levels of the stress hormone cortisol, suggesting costs of high dominance. Chapter 11 shows early pubertal timing relates to the visual appearance of skin, perhaps because of lower sebum production among early developing men, leading to them having darker, less reflective skin. This may reflect accelerated ageing of early developing males, potentially representing a cost to longevity. http://hdl.handle.net/10023/686 Abstract: This program of research was designed to examine the role of thought suppression in the retrieval of autobiographical memories (ABMs). The principal theory proposed here is that thought suppression is an important mechanism in explaining certain ABM retrieval patterns relevant to trauma and self-harm. Study 1 examined the role of thought suppression as a correlate of ABM retrieval in a nonclinical student sample, and showed that higher levels of thought suppression were significantly correlated with the faster recall of negative episodic ABMs as well as the recall of fewer personal semantic memories. Study 2 used a suppression manipulation procedure designed to examine whether this was a causal relationship, and revealed that induced thought suppression directly led to a significant enhancement in the retrieval of negative episodic ABMs as well as significantly fewer overgeneral first responses to negative cues. Furthermore, the induced thought suppression also resulted in the recall of significantly fewer personal semantic memories. Together these results support the theory that thought suppression is an important factor in ABM recall. The enhanced recall of negative memories could be particularly important in individuals who are self-harming, suicidal and/or suffering from PTSD, as enhanced negative recall has previously been observed in these populations. In order to further examine how thought suppression affects ABM retrieval and whether the enhanced negative recall observed in Study 2 was a result of mood-congruent recall, Study 3 used a similar suppression manipulation paradigm to examine the effects of induced thought suppression on mood. The results suggested that the enhanced negative ABM recall was unlikely to have been a by-product of the suppression manipulation resulting in a more negative mood state. Finally, Study 4 examined the role of thought suppression and ABM recall in a clinical sample of self-harming adolescents (who also reported high levels of post-traumatic stress symptoms). The results showed that levels of thought suppression were significantly higher in the self-harmers than the control group, indicating that thought suppression is an important coping mechanism in self-harmers. Furthermore, in terms of the autobiographical memory retrieval, it was found that the self-harmers were significantly faster in their retrieval of negative episodic ABMs and recalled fewer personal semantic memories than the control group. Multiple regression analysis of the data revealed that thought suppression remained as the most important predictor of variability in negative episodic ABM retrieval and personal semantic memory retrieval, even when variability explained by symptoms of depression and PTSD was considered. This program of research extends current theories of ABM retrieval by identifying thought suppression as a cognitive mechanism that directly affects the retrieval of both episodic as well as personal semantic ABMs. The theoretical importance and clinical relevance of this program of research are discussed. 2008-11-27T00:00:00Z Neufeind, Julia This program of research was designed to examine the role of thought suppression in the retrieval of autobiographical memories (ABMs). The principal theory proposed here is that thought suppression is an important mechanism in explaining certain ABM retrieval patterns relevant to trauma and self-harm. Study 1 examined the role of thought suppression as a correlate of ABM retrieval in a nonclinical student sample, and showed that higher levels of thought suppression were significantly correlated with the faster recall of negative episodic ABMs as well as the recall of fewer personal semantic memories. Study 2 used a suppression manipulation procedure designed to examine whether this was a causal relationship, and revealed that induced thought suppression directly led to a significant enhancement in the retrieval of negative episodic ABMs as well as significantly fewer overgeneral first responses to negative cues. Furthermore, the induced thought suppression also resulted in the recall of significantly fewer personal semantic memories. Together these results support the theory that thought suppression is an important factor in ABM recall. The enhanced recall of negative memories could be particularly important in individuals who are self-harming, suicidal and/or suffering from PTSD, as enhanced negative recall has previously been observed in these populations. In order to further examine how thought suppression affects ABM retrieval and whether the enhanced negative recall observed in Study 2 was a result of mood-congruent recall, Study 3 used a similar suppression manipulation paradigm to examine the effects of induced thought suppression on mood. The results suggested that the enhanced negative ABM recall was unlikely to have been a by-product of the suppression manipulation resulting in a more negative mood state. Finally, Study 4 examined the role of thought suppression and ABM recall in a clinical sample of self-harming adolescents (who also reported high levels of post-traumatic stress symptoms). The results showed that levels of thought suppression were significantly higher in the self-harmers than the control group, indicating that thought suppression is an important coping mechanism in self-harmers. Furthermore, in terms of the autobiographical memory retrieval, it was found that the self-harmers were significantly faster in their retrieval of negative episodic ABMs and recalled fewer personal semantic memories than the control group. Multiple regression analysis of the data revealed that thought suppression remained as the most important predictor of variability in negative episodic ABM retrieval and personal semantic memory retrieval, even when variability explained by symptoms of depression and PTSD was considered. This program of research extends current theories of ABM retrieval by identifying thought suppression as a cognitive mechanism that directly affects the retrieval of both episodic as well as personal semantic ABMs. The theoretical importance and clinical relevance of this program of research are discussed. http://hdl.handle.net/10023/681 Abstract: This thesis explores social learning in mother-reared and “enculturated” capuchin monkeys (Cebus apella). At the outset a framework for understanding the social influence on learning is discussed, followed by a review of the social and cognitive abilities of capuchin monkeys, establishing the rationale for studying social learning in this species. Studies of wild capuchins suggest an important role for social learning but experiments with captive subjects have generally failed to support this. Some potential reasons for the lack of evidence in experimental settings are given. An example of using the two - method design to test social learning in acquiring behaviour by enculturated subjects is addressed. The results are related to findings with other species tested with a similar apparatus. Before testing mother-reared monkeys, an observational study of the object manipulation and tool-use repertoire of the subjects was carried out in order to facilitate the design of suitable social learning tasks for these monkeys. The first empirical study in Chapter 6 reports results of experiments with the enculturated and mother-reared capuchin monkeys employing the two -action method together with a third control group. The enculturated monkeys exhibited high fidelity copying that included the specific tool use technique witnessed while opening the foraging box. Mother-reared monkeys exhibited fidelity at a lower level, tending only to re-create the results the model had achieved. The second empirical study in Chapter 7 tested whether capuchin monkeys could show cumulative cultural learning manifested in the ability to switch from an established mode of manipulating a dipping box to a complex yet more advantageous one. Both populations were able to do so. The enculturated monkeys, as in the previous study, showed higher fidelity copying of the model. The last experiment was a preliminary study employing the “do as I do” method which was carried out with four of the enculturated monkeys. It provides suggestive evidence for at least one monkey's understanding of the task. The results of the studies are discussed in relation to previous experimental research as well as to data from capuchin monkeys in nature. The possible role of enculturation in social learning ability is considered. 2008-01-01T00:00:00Z Fredman, Tamar This thesis explores social learning in mother-reared and “enculturated” capuchin monkeys (Cebus apella). At the outset a framework for understanding the social influence on learning is discussed, followed by a review of the social and cognitive abilities of capuchin monkeys, establishing the rationale for studying social learning in this species. Studies of wild capuchins suggest an important role for social learning but experiments with captive subjects have generally failed to support this. Some potential reasons for the lack of evidence in experimental settings are given. An example of using the two - method design to test social learning in acquiring behaviour by enculturated subjects is addressed. The results are related to findings with other species tested with a similar apparatus. Before testing mother-reared monkeys, an observational study of the object manipulation and tool-use repertoire of the subjects was carried out in order to facilitate the design of suitable social learning tasks for these monkeys. The first empirical study in Chapter 6 reports results of experiments with the enculturated and mother-reared capuchin monkeys employing the two -action method together with a third control group. The enculturated monkeys exhibited high fidelity copying that included the specific tool use technique witnessed while opening the foraging box. Mother-reared monkeys exhibited fidelity at a lower level, tending only to re-create the results the model had achieved. The second empirical study in Chapter 7 tested whether capuchin monkeys could show cumulative cultural learning manifested in the ability to switch from an established mode of manipulating a dipping box to a complex yet more advantageous one. Both populations were able to do so. The enculturated monkeys, as in the previous study, showed higher fidelity copying of the model. The last experiment was a preliminary study employing the “do as I do” method which was carried out with four of the enculturated monkeys. It provides suggestive evidence for at least one monkey's understanding of the task. The results of the studies are discussed in relation to previous experimental research as well as to data from capuchin monkeys in nature. The possible role of enculturation in social learning ability is considered. http://hdl.handle.net/10023/680 Abstract: The main aim of this thesis was to investigate decision making from a broad developmental perspective to clarify the role of the underlying mechanisms influencing it. Problem solving and cognitive inhibitory capacity were chartered initially through the use of hypothetical vignettes depicting socially relevant situations and through the use of the Stroop task, to tap into automatic inhibitory capacity. Initial assumptions that prefrontal cortical refinement would denote enhanced social problem ability were not confirmed. Experience emerged as distinct factor in problem solving/decision-making, with the youngest participants equally as effective in producing solutions to situations that they had the most experience in. A shift in development is observed with maturation denoting greater experience and this being applied directly to problem solving and decision-making situations. Education was identified as a possible contributory factor in decision-making and this was explored in a cross-cultural study that tapped into a non-schooled population. The results reinforced the centrality of experience in shaping decision-making. Decision-making in regards to the use of experience was then looked at through real life decision-making situations, where adolescents were asked to provide their knowledge or experience of situations where risk was involved. Adolescents possessed the necessary knowledge to distinguish between optimal and sub-optimal decisions in terms of the consequences that risk behaviours carried with them. However, many still chose to engage in risky behaviours. This paradox could also be explained by actual experience, with the suggestion that positive experience in a peer group was serving as a pool from which adolescents drew to make future decision-making. If risk behaviours were not experienced adversely, the likelihood of their repetition was high. Taken together the findings suggest that adolescents are well equipped with the cognitive skills to make decisions. Compared to younger children, they have more experience of a greater range of situations from which to extrapolate responses from. They also have a great deal of knowledge and information about the negative consequences associated with a range of challenging situations and risk-taking behaviours. However, when faced with decisions in the social domain, the behaviour of friends and perceptions of what other people are doing are powerful influences on adolescent decisions. 2009-06-24T00:00:00Z Escalante-Mead, P. R. The main aim of this thesis was to investigate decision making from a broad developmental perspective to clarify the role of the underlying mechanisms influencing it. Problem solving and cognitive inhibitory capacity were chartered initially through the use of hypothetical vignettes depicting socially relevant situations and through the use of the Stroop task, to tap into automatic inhibitory capacity. Initial assumptions that prefrontal cortical refinement would denote enhanced social problem ability were not confirmed. Experience emerged as distinct factor in problem solving/decision-making, with the youngest participants equally as effective in producing solutions to situations that they had the most experience in. A shift in development is observed with maturation denoting greater experience and this being applied directly to problem solving and decision-making situations. Education was identified as a possible contributory factor in decision-making and this was explored in a cross-cultural study that tapped into a non-schooled population. The results reinforced the centrality of experience in shaping decision-making. Decision-making in regards to the use of experience was then looked at through real life decision-making situations, where adolescents were asked to provide their knowledge or experience of situations where risk was involved. Adolescents possessed the necessary knowledge to distinguish between optimal and sub-optimal decisions in terms of the consequences that risk behaviours carried with them. However, many still chose to engage in risky behaviours. This paradox could also be explained by actual experience, with the suggestion that positive experience in a peer group was serving as a pool from which adolescents drew to make future decision-making. If risk behaviours were not experienced adversely, the likelihood of their repetition was high. Taken together the findings suggest that adolescents are well equipped with the cognitive skills to make decisions. Compared to younger children, they have more experience of a greater range of situations from which to extrapolate responses from. They also have a great deal of knowledge and information about the negative consequences associated with a range of challenging situations and risk-taking behaviours. However, when faced with decisions in the social domain, the behaviour of friends and perceptions of what other people are doing are powerful influences on adolescent decisions. http://hdl.handle.net/10023/660 Abstract: Converging experimental and observational evidence suggests that some non-human primates are able to co-orient with shifts in visual attention, both of conspecifics and humans. However, the underlying cognitive mechanisms involved are unclear. To investigate attention-following in Diana monkeys (Cercopithecus diana diana), we used photographs of familiar conspecifics orienting towards one of two locations. A subject monkey was shown a photograph, and shortly afterwards a toy appeared at one location or the other. The toy’s position therefore either matched the location signalled by the head and body orientation of the photographed monkey (compatible), or was opposite to that location (incompatible). Overall, monkeys’ first inspections, total duration of looking, and number of looks were more likely to be directed to the compatible location, i.e. towards the direction of attention shown in the photograph. Furthermore, when a photograph of an adult monkey signalled attention to one location, but the toy appeared at the opposite (incompatible) location, subjects re-inspected the monkey photographs more often than when the toy appeared at the compatible location, suggesting a violation of expectancy. This effect was not the case if the photograph was of an immature animal. Our results show that attention-following was not limited to simple reflexive orienting by the monkeys, and that monkeys perceived a relationship existing between agent and object of attention. 2004-01-01T00:00:00Z Scerif, Gaia Gómez, Juan Carlos Byrne, RW Converging experimental and observational evidence suggests that some non-human primates are able to co-orient with shifts in visual attention, both of conspecifics and humans. However, the underlying cognitive mechanisms involved are unclear. To investigate attention-following in Diana monkeys (Cercopithecus diana diana), we used photographs of familiar conspecifics orienting towards one of two locations. A subject monkey was shown a photograph, and shortly afterwards a toy appeared at one location or the other. The toy’s position therefore either matched the location signalled by the head and body orientation of the photographed monkey (compatible), or was opposite to that location (incompatible). Overall, monkeys’ first inspections, total duration of looking, and number of looks were more likely to be directed to the compatible location, i.e. towards the direction of attention shown in the photograph. Furthermore, when a photograph of an adult monkey signalled attention to one location, but the toy appeared at the opposite (incompatible) location, subjects re-inspected the monkey photographs more often than when the toy appeared at the compatible location, suggesting a violation of expectancy. This effect was not the case if the photograph was of an immature animal. Our results show that attention-following was not limited to simple reflexive orienting by the monkeys, and that monkeys perceived a relationship existing between agent and object of attention. http://hdl.handle.net/10023/634 Abstract: While most human language is expressed verbally, the gestures produced concurrent to speech provide additional information, help listeners interpret meaning, and provide insight into the cognitive processes of the speaker. Several theories have suggested that gesture played an important, possibly central, role in the evolution of language. Great apes have been shown to use gestures flexibly in different situations and to modify their gestures in response to changing contexts. However, it has not previously been determined whether ape gestures are defined by structural variables, carry meaning, are used to intentionally communicate specific information to others, or can be used strategically to overcome miscommunication. To investigate these questions, I studied three captive populations of orangutans (Pongo pygmaeus and P. abelii) in European zoos for 10 months. Sixty-four different gestures, defined through similarities in structure and use, were included in the study after meeting strict criteria for intentional usage. More than half of the gesture types were found to coincide frequently with specific goals of signallers, and were accordingly identified as having meanings. Both structural and social variables were found to determine gesture meaning. The recipient’s gaze in both the present and the past, and the recipient’s apparent understanding of the signaller’s gestures, affected the strategies orangutans employed in their attempts to communicate when confronted with different types of communicative failure (e.g. not seeing, ignoring, misunderstanding, or rejecting a gesture). Maternal influence affected the object-directed behaviour and gestures of infants, who shared more gestures with their mothers than with other females. These findings demonstrate that gesture can be used as a medium to investigate not only the communication but also the cognition of great apes, and indicate that orangutans are more sensitive to the perceptions and knowledge states of others than previously thought. 2009-06-01T00:00:00Z Cartmill, Erica A. While most human language is expressed verbally, the gestures produced concurrent to speech provide additional information, help listeners interpret meaning, and provide insight into the cognitive processes of the speaker. Several theories have suggested that gesture played an important, possibly central, role in the evolution of language. Great apes have been shown to use gestures flexibly in different situations and to modify their gestures in response to changing contexts. However, it has not previously been determined whether ape gestures are defined by structural variables, carry meaning, are used to intentionally communicate specific information to others, or can be used strategically to overcome miscommunication. To investigate these questions, I studied three captive populations of orangutans (Pongo pygmaeus and P. abelii) in European zoos for 10 months. Sixty-four different gestures, defined through similarities in structure and use, were included in the study after meeting strict criteria for intentional usage. More than half of the gesture types were found to coincide frequently with specific goals of signallers, and were accordingly identified as having meanings. Both structural and social variables were found to determine gesture meaning. The recipient’s gaze in both the present and the past, and the recipient’s apparent understanding of the signaller’s gestures, affected the strategies orangutans employed in their attempts to communicate when confronted with different types of communicative failure (e.g. not seeing, ignoring, misunderstanding, or rejecting a gesture). Maternal influence affected the object-directed behaviour and gestures of infants, who shared more gestures with their mothers than with other females. These findings demonstrate that gesture can be used as a medium to investigate not only the communication but also the cognition of great apes, and indicate that orangutans are more sensitive to the perceptions and knowledge states of others than previously thought. http://hdl.handle.net/10023/535 Abstract: The aims of the present thesis were two fold. The first aim was to investigate the relationship between self-referential and emotional processing. The second aim was to investigate the extent to which self-referential processing is altered as a function of mood. In order to address these two aims, a variety of behavioural and physiological measures were recorded and a new methodology was employed in the following experimental chapters. The aim of experiment one was to investigate how non-dysphoric and dysphoric individuals evaluate the emotional valence and self-referential content of word stimuli at a behavioural level. A self-positivity bias was identified in non-dysphoric individuals, positive words were rated as self-referential and negative words were rated as non-self-referential. Compared to non-dysphoric individuals, dysphoric individualsâ evaluations of self-reference but not emotional valence were altered. Event-related potentials (ERPs) were employed in experiment two to investigate self-referential processing at a neural level. A two stage model of processing was identified in which, an evaluation of emotional valence was found to occur prior to an interaction between self-reference and emotional valence. A self-positivity bias was identified in the ERP component known as the N400. ERP waves were more negative going to self negative and non-self-positive words when compared to self-positive and non-self-negative words. This bias was explained in terms of the semantic mismatch hypothesis. The aim of experiment three was to investigate how the neural processing of self-referential and emotional information is altered as a function of mood. Differences between nondysphoric and dysphoric individuals were identified during the early stages of ii processing in an emotion task. Between group differences were identified during the later stages of processing in a self-reference task, around 400 ms. Skin conductance and heart rate were employed in experiment four to examine autonomic responses during self-referential and emotional processing in healthy individuals. Both decision-making tasks were found to elicit similar physiological responses. These findings were taken to suggest that a large component of self-referential processing involves the processing of emotional information. Finally, the aim of experiment five was to investigate if person-referent processing was altered during the experience of a negative mood. The behavioural and neural responses of non-dysphoric and dysphoric individuals were compared across self-referent and other-referent decision-making tasks. Between group differences were specific to the self-reference task at the behavioural level. However, group differences were identified in both the self-referent and other-referent tasks at the neural level. The results provide partial support for the hypothesis that negative mood is associated with specific impairments in self-referential processing. Overall the results of the present thesis illustrate that the processing of emotional information plays a large role in self-referential decision-making. Furthermore, the N400 was found be involved in this type of decision-making at the semantic level. Negative mood was associated with greater changes in self-referential processing than in other forms of emotional or person-referent processing. In the final chapter, a two stage model is proposed to account for self-referential processing. The implications of this model are discussed in terms of two macro-cognitive theories, interacting cognitive subsystems (ICS) and SPAARs. Finally, the limitations and future directions for developing this line of research are outlined. 2008-06-26T00:00:00Z Watson, Lynn A. S. The aims of the present thesis were two fold. The first aim was to investigate the relationship between self-referential and emotional processing. The second aim was to investigate the extent to which self-referential processing is altered as a function of mood. In order to address these two aims, a variety of behavioural and physiological measures were recorded and a new methodology was employed in the following experimental chapters. The aim of experiment one was to investigate how non-dysphoric and dysphoric individuals evaluate the emotional valence and self-referential content of word stimuli at a behavioural level. A self-positivity bias was identified in non-dysphoric individuals, positive words were rated as self-referential and negative words were rated as non-self-referential. Compared to non-dysphoric individuals, dysphoric individualsâ evaluations of self-reference but not emotional valence were altered. Event-related potentials (ERPs) were employed in experiment two to investigate self-referential processing at a neural level. A two stage model of processing was identified in which, an evaluation of emotional valence was found to occur prior to an interaction between self-reference and emotional valence. A self-positivity bias was identified in the ERP component known as the N400. ERP waves were more negative going to self negative and non-self-positive words when compared to self-positive and non-self-negative words. This bias was explained in terms of the semantic mismatch hypothesis. The aim of experiment three was to investigate how the neural processing of self-referential and emotional information is altered as a function of mood. Differences between nondysphoric and dysphoric individuals were identified during the early stages of ii processing in an emotion task. Between group differences were identified during the later stages of processing in a self-reference task, around 400 ms. Skin conductance and heart rate were employed in experiment four to examine autonomic responses during self-referential and emotional processing in healthy individuals. Both decision-making tasks were found to elicit similar physiological responses. These findings were taken to suggest that a large component of self-referential processing involves the processing of emotional information. Finally, the aim of experiment five was to investigate if person-referent processing was altered during the experience of a negative mood. The behavioural and neural responses of non-dysphoric and dysphoric individuals were compared across self-referent and other-referent decision-making tasks. Between group differences were specific to the self-reference task at the behavioural level. However, group differences were identified in both the self-referent and other-referent tasks at the neural level. The results provide partial support for the hypothesis that negative mood is associated with specific impairments in self-referential processing. Overall the results of the present thesis illustrate that the processing of emotional information plays a large role in self-referential decision-making. Furthermore, the N400 was found be involved in this type of decision-making at the semantic level. Negative mood was associated with greater changes in self-referential processing than in other forms of emotional or person-referent processing. In the final chapter, a two stage model is proposed to account for self-referential processing. The implications of this model are discussed in terms of two macro-cognitive theories, interacting cognitive subsystems (ICS) and SPAARs. Finally, the limitations and future directions for developing this line of research are outlined. http://hdl.handle.net/10023/507 Abstract: The reinforcing properties of nicotine depend partly on cholinergic projections from the pedunculopontine tegmental (PPTg) and laterodorsal tegmental (LDTg) nuclei to midbrain dopamine neurons in the ventral tegmental area (VTA) and substantia nigra pars compacta (SNc). Neuronal activation was investigated using Fos expression in these areas following acute (0, 0.1, 0.4, 0.8mg/kg) or chronic systemic nicotine (0, 0.1, 0.4, 0.8, 1.0mg/kg given once per day for 5 days). We also examined co-localization of Fos expression in bNOS and TH positive neurons to determine what populations of neurons were activated by nicotine. Acute nicotine resulted in dose related Fos expression, with the biggest increase seen after 0.4mg/kg nicotine, but no co-localization occurred with bNOS in the PPTg/LDTg. Surprisingly, nicotine also failed to activate midbrain dopamine neurons. After animals were sensitized to nicotine there was a similar dose response curve in Fos expression, but the biggest increase was seen after 0.8mg/kg nicotine. Chronic nicotine, like acute, also preferentially activated non-cholinergic neurons in the LDTg and PPTg and non-dopamine neurons in the SNc and VTA. Further experiments looked at the mechanisms of Fos expression after nicotine administration. Fos expression in the LDTg/PPTg and SNc/VTA was suppressed after d-amphetamine, despite an increase in locomotor activity, suggesting that the increased Fos expression after chronic nicotine was not simply due to the locomotor activating effects of sensitized nicotine. Blocking autoreceptors in the dopaminergic midbrain by haloperidol pre-treatment did not increase Fos expression in dopamine neurons indicating that the inhibitory mechanism was not dependent on local autoreceptors. Novel methods of visualising and lesioning GABA neurons in the mesopontine tegmentum and midbrain were also examined. The data suggest that the mechanisms by which dopamine is involved in the pharmacological actions of passively administered nicotine are more complex than was first thought and that the role of non-dopamine neurons in the VTA (possibly GABA or glutamate containing) are also important. 2008-06-01T00:00:00Z Porter, Ailsa The reinforcing properties of nicotine depend partly on cholinergic projections from the pedunculopontine tegmental (PPTg) and laterodorsal tegmental (LDTg) nuclei to midbrain dopamine neurons in the ventral tegmental area (VTA) and substantia nigra pars compacta (SNc). Neuronal activation was investigated using Fos expression in these areas following acute (0, 0.1, 0.4, 0.8mg/kg) or chronic systemic nicotine (0, 0.1, 0.4, 0.8, 1.0mg/kg given once per day for 5 days). We also examined co-localization of Fos expression in bNOS and TH positive neurons to determine what populations of neurons were activated by nicotine. Acute nicotine resulted in dose related Fos expression, with the biggest increase seen after 0.4mg/kg nicotine, but no co-localization occurred with bNOS in the PPTg/LDTg. Surprisingly, nicotine also failed to activate midbrain dopamine neurons. After animals were sensitized to nicotine there was a similar dose response curve in Fos expression, but the biggest increase was seen after 0.8mg/kg nicotine. Chronic nicotine, like acute, also preferentially activated non-cholinergic neurons in the LDTg and PPTg and non-dopamine neurons in the SNc and VTA. Further experiments looked at the mechanisms of Fos expression after nicotine administration. Fos expression in the LDTg/PPTg and SNc/VTA was suppressed after d-amphetamine, despite an increase in locomotor activity, suggesting that the increased Fos expression after chronic nicotine was not simply due to the locomotor activating effects of sensitized nicotine. Blocking autoreceptors in the dopaminergic midbrain by haloperidol pre-treatment did not increase Fos expression in dopamine neurons indicating that the inhibitory mechanism was not dependent on local autoreceptors. Novel methods of visualising and lesioning GABA neurons in the mesopontine tegmentum and midbrain were also examined. The data suggest that the mechanisms by which dopamine is involved in the pharmacological actions of passively administered nicotine are more complex than was first thought and that the role of non-dopamine neurons in the VTA (possibly GABA or glutamate containing) are also important. http://hdl.handle.net/10023/494 Abstract: Mammalian brains consist of billions of neurons, each capable of independent electrical activity. Information in the brain is represented by the pattern of activation of this large neural population, forming a neural code. The neural code defines what pattern of neural activity corresponds to each represented information item. In the sensory system, such items may indicate the presence of a stimulus object or the value of some stimulus parameter, assuming that each time this item is represented the neural activity pattern will be the same or at least similar. One important and relatively simple property of this code is the fraction of neurons that are strongly active at any one time. For a set of N binary neurons (which can either be 'active' or 'inactive'), the average (i.e., expected value) of this fraction across all information items is the sparseness of the code. This average fraction can vary from close to 0 to about 1/2. Average fractions above 1/2 can always be decreased below 1/2 without loss of information by replacing each active neuron with an inactive one, and vice versa. Sparse coding is the representation of items by the strong activation of a relatively small set of neurons. For each stimulus, this is a different subset of all available neurons. Description: The(frequently updated) original version is avalable at http://www.scholarpedia.org/article/Sparse_coding 2008-01-01T00:00:00Z Foldiak, P Endres, D M Mammalian brains consist of billions of neurons, each capable of independent electrical activity. Information in the brain is represented by the pattern of activation of this large neural population, forming a neural code. The neural code defines what pattern of neural activity corresponds to each represented information item. In the sensory system, such items may indicate the presence of a stimulus object or the value of some stimulus parameter, assuming that each time this item is represented the neural activity pattern will be the same or at least similar. One important and relatively simple property of this code is the fraction of neurons that are strongly active at any one time. For a set of N binary neurons (which can either be 'active' or 'inactive'), the average (i.e., expected value) of this fraction across all information items is the sparseness of the code. This average fraction can vary from close to 0 to about 1/2. Average fractions above 1/2 can always be decreased below 1/2 without loss of information by replacing each active neuron with an inactive one, and vice versa. Sparse coding is the representation of items by the strong activation of a relatively small set of neurons. For each stimulus, this is a different subset of all available neurons. http://hdl.handle.net/10023/473 Abstract: The peristimulus time histogram (PSTH) and its more continuous cousin, the spike density function (SDF) are staples in the analytic toolkit of neurophysiologists. The former is usually obtained by binning spike trains, whereas the standard method for the latter is smoothing with a Gaussian kernel. Selection of a bin width or a kernel size is often done in an relatively arbitrary fashion, even though there have been recent attempts to remedy this situation. We develop an exact Bayesian, generative model approach to estimating PSTHs and demonstate its superiority to competing methods. Further advantages of our scheme include automatic complexity control and error bars on its predictions. 2008-01-01T00:00:00Z Endres, D M Oram, M W Schindelin, J.E. Foldiak, P The peristimulus time histogram (PSTH) and its more continuous cousin, the spike density function (SDF) are staples in the analytic toolkit of neurophysiologists. The former is usually obtained by binning spike trains, whereas the standard method for the latter is smoothing with a Gaussian kernel. Selection of a bin width or a kernel size is often done in an relatively arbitrary fashion, even though there have been recent attempts to remedy this situation. We develop an exact Bayesian, generative model approach to estimating PSTHs and demonstate its superiority to competing methods. Further advantages of our scheme include automatic complexity control and error bars on its predictions. http://hdl.handle.net/10023/436 Abstract: In the wild, a variety of inter-group behavioural differences have been reported for chimpanzees (Pan troglodytes) and it has been suggested that these may have resulted from social learning. To determine whether chimpanzees show the necessary propensity for social learning, groups of captive chimpanzees were tested in a series of experiments involving the use of two-action and bidirectional apparatuses. For comparison, and to shed light on any contrasts between our own and chimpanzee learning strategies, similar tests were also conducted with children (Homo sapiens) to ascertain the nature of their observational learning when watching conspecifics. Through the use of open diffusion and diffusion chain techniques, it was shown that both species learnt how to operate different foraging devices from observing an expert conspecific and this learning was strong enough for the generation of behavioural traditions which passed along multiple test ‘generations’. Additionally, ghost conditions were used to distinguish imitative and emulative learning by both species. With one of the two test devices used (the Slide-box) the first evidence for emulation learning by chimpanzees, through the use of a ghost condition, was shown. Children in this condition also showed apparent emulation; a contrast to previous research which has concluded that children tend to rely on imitation. Additionally, to test its potential for use in future social learning experiments, the ability of chimpanzees to learn from video-footage of an unknown conspecific was tested. It was found that the chimpanzees not only learnt how to operate two devices from observing this footage but also used the same alternative method used by the model chimpanzee. 2008-01-01T00:00:00Z Hopper, Lydia Meriel In the wild, a variety of inter-group behavioural differences have been reported for chimpanzees (Pan troglodytes) and it has been suggested that these may have resulted from social learning. To determine whether chimpanzees show the necessary propensity for social learning, groups of captive chimpanzees were tested in a series of experiments involving the use of two-action and bidirectional apparatuses. For comparison, and to shed light on any contrasts between our own and chimpanzee learning strategies, similar tests were also conducted with children (Homo sapiens) to ascertain the nature of their observational learning when watching conspecifics. Through the use of open diffusion and diffusion chain techniques, it was shown that both species learnt how to operate different foraging devices from observing an expert conspecific and this learning was strong enough for the generation of behavioural traditions which passed along multiple test ‘generations’. Additionally, ghost conditions were used to distinguish imitative and emulative learning by both species. With one of the two test devices used (the Slide-box) the first evidence for emulation learning by chimpanzees, through the use of a ghost condition, was shown. Children in this condition also showed apparent emulation; a contrast to previous research which has concluded that children tend to rely on imitation. Additionally, to test its potential for use in future social learning experiments, the ability of chimpanzees to learn from video-footage of an unknown conspecific was tested. It was found that the chimpanzees not only learnt how to operate two devices from observing this footage but also used the same alternative method used by the model chimpanzee. http://hdl.handle.net/10023/373 Abstract: The thalamic reticular nucleus (TRN), and especially its caudal, sensory-related, half (cTRN), has been hypothesised for years to be at the very heart of thalamic sensory processing modulation, and attentional processes in particular. Very limited behavioural evidence is available, nonetheless, in support of such a functional attribution. In this thesis we carried out a series of investigations, combining immunocytochemical and lesion techniques with tests of behaviour, in order to examine the potential role of cTRN in attention and identify the attentional processes, if any, that it is more likely to contribute to. In chapter II, we looked at the Fos activation levels within modality-specific sectors of cTRN following attentive behaviours to stimulation of different modalities. We observed a selective activation of the visual sector of cTRN in visually attentive animals but not in tactilely attentive, yet visually stimulated, animals, thus demonstrating an involvement of that area in processes of visual attention. In chapter III we looked at the role of cTRN in cross-modal expressions of divided attention. We found that its removal, through neurotoxic lesioning, did not result in any behavioural costs with regard to the division of attention. Detriments in response accuracy, however, suggested that cTRN may be involved in stimulus processing enhancement operations, unrelated with the division of attention. Finally, in chapters IV and V, we looked at the effects of lesions of the visual sector of cTRN (TRNvis) on the ability to orient attention covertly within visual space. We found that the removal of TRNvis did not affect visual covert orienting behaviour, both when this is triggered by exogenous and endogenous means. Overall our results suggest that even though cTRN appears to be involved in some aspects of attention, it does not represent a necessary structure for the generation and operation of certain other forms of attention. 2007-11-01T00:00:00Z Petrof, Iraklis The thalamic reticular nucleus (TRN), and especially its caudal, sensory-related, half (cTRN), has been hypothesised for years to be at the very heart of thalamic sensory processing modulation, and attentional processes in particular. Very limited behavioural evidence is available, nonetheless, in support of such a functional attribution. In this thesis we carried out a series of investigations, combining immunocytochemical and lesion techniques with tests of behaviour, in order to examine the potential role of cTRN in attention and identify the attentional processes, if any, that it is more likely to contribute to. In chapter II, we looked at the Fos activation levels within modality-specific sectors of cTRN following attentive behaviours to stimulation of different modalities. We observed a selective activation of the visual sector of cTRN in visually attentive animals but not in tactilely attentive, yet visually stimulated, animals, thus demonstrating an involvement of that area in processes of visual attention. In chapter III we looked at the role of cTRN in cross-modal expressions of divided attention. We found that its removal, through neurotoxic lesioning, did not result in any behavioural costs with regard to the division of attention. Detriments in response accuracy, however, suggested that cTRN may be involved in stimulus processing enhancement operations, unrelated with the division of attention. Finally, in chapters IV and V, we looked at the effects of lesions of the visual sector of cTRN (TRNvis) on the ability to orient attention covertly within visual space. We found that the removal of TRNvis did not affect visual covert orienting behaviour, both when this is triggered by exogenous and endogenous means. Overall our results suggest that even though cTRN appears to be involved in some aspects of attention, it does not represent a necessary structure for the generation and operation of certain other forms of attention. http://hdl.handle.net/10023/368 Abstract: Our eyes are horizontally separated in the head by approximately 6.5cm. As a result of this separation there are subtle differences in the position of corresponding image points within the two eyes. The horizontal component of this binocular positional difference is termed horizontal disparity. Horizontal disparity is an important visual cue as once scaled with an estimate of the viewing distance, it can theoretically provide full metric information about the structure of the world. This thesis will address the issue of how binocular visual cues are used by the human visual system for the estimation of three-dimensional (3-D) shape for perception and visuomotor control. The research presented is particularly focused on understanding why biases in the perception of 3-D shape from binocular cues are found, their importance for perception and visuomotor control and how these biases may be overcome by combining binocular cues with other sources of visual information. 2007-11-30T00:00:00Z Scarfe, Peter Our eyes are horizontally separated in the head by approximately 6.5cm. As a result of this separation there are subtle differences in the position of corresponding image points within the two eyes. The horizontal component of this binocular positional difference is termed horizontal disparity. Horizontal disparity is an important visual cue as once scaled with an estimate of the viewing distance, it can theoretically provide full metric information about the structure of the world. This thesis will address the issue of how binocular visual cues are used by the human visual system for the estimation of three-dimensional (3-D) shape for perception and visuomotor control. The research presented is particularly focused on understanding why biases in the perception of 3-D shape from binocular cues are found, their importance for perception and visuomotor control and how these biases may be overcome by combining binocular cues with other sources of visual information. http://hdl.handle.net/10023/344 Abstract: Previous research has indicated that depression and thinking style (rumination versus distraction) interact to influence cognitive processing. Depressed ruminators produce more categoric autobiographical memories (AM) (i.e., a summary of repeated memories), and also demonstrate poorer SPS performance than depressed distracters and matched controls. The quality of AM retrieval during SPS is also related to the effectiveness of SPS solutions such that categoric AM retrieval during SPS contributes to poorer SPS. Therefore, the first aim of this thesis was to extend previous work by further investigating how an induced rumination/distraction influences subsequent AM retrieval during SPS and SPS performance. The first two studies examined how thinking style influences SPS and AM retrieval during SPS in a dysphoric (study 1) versus clinically depressed sample (study 2). The results indicated that rumination has a detrimental effect on SPS in both dysphoric and clinically depressed samples, with more pronounced effects in the clinical group. Rumination also appeared to influence AM retrieval during SPS for the clinically depressed group but not the dysphoric group. Moreover, in both samples, SPS performance was associated with the type of AM retrieval involved in the SPS process. As most studies investigating cognitive processes in depression have focused on Western people, a second aim of this thesis was to examine the association between thinking style, AM retrieval and SPS performance in depression from a cross-cultural perspective. The first cross-cultural study (Study 3) looked at AM retrieval on the AMT cueing task and the second cross-cultural study (Study 4) investigated whether these associations between thinking style, SPS and AM retrieval would vary across different cultures. Culture interacted with depression to influence AM retrieval on the AMT cueing task. However study 4 demonstrated that there seemed to be no interaction between culture, rumination and depression on SPS performance and AM retrieval during SPS. 2007-02-01T00:00:00Z Kao, Chih-Mei Previous research has indicated that depression and thinking style (rumination versus distraction) interact to influence cognitive processing. Depressed ruminators produce more categoric autobiographical memories (AM) (i.e., a summary of repeated memories), and also demonstrate poorer SPS performance than depressed distracters and matched controls. The quality of AM retrieval during SPS is also related to the effectiveness of SPS solutions such that categoric AM retrieval during SPS contributes to poorer SPS. Therefore, the first aim of this thesis was to extend previous work by further investigating how an induced rumination/distraction influences subsequent AM retrieval during SPS and SPS performance. The first two studies examined how thinking style influences SPS and AM retrieval during SPS in a dysphoric (study 1) versus clinically depressed sample (study 2). The results indicated that rumination has a detrimental effect on SPS in both dysphoric and clinically depressed samples, with more pronounced effects in the clinical group. Rumination also appeared to influence AM retrieval during SPS for the clinically depressed group but not the dysphoric group. Moreover, in both samples, SPS performance was associated with the type of AM retrieval involved in the SPS process. As most studies investigating cognitive processes in depression have focused on Western people, a second aim of this thesis was to examine the association between thinking style, AM retrieval and SPS performance in depression from a cross-cultural perspective. The first cross-cultural study (Study 3) looked at AM retrieval on the AMT cueing task and the second cross-cultural study (Study 4) investigated whether these associations between thinking style, SPS and AM retrieval would vary across different cultures. Culture interacted with depression to influence AM retrieval on the AMT cueing task. However study 4 demonstrated that there seemed to be no interaction between culture, rumination and depression on SPS performance and AM retrieval during SPS. http://hdl.handle.net/10023/332 Abstract: Mate preferences provide an opportunity to explore the validity of evolutionary and social role origin theories of sex differences in human behaviour. In evolutionary models, preferences are sex-specific adaptive responses to constraints to reproductive success. In social role models, sex differences arise from the allocation of men and women to different gender roles. I explored the effects of the status of women on preferences to assess the validity of the origin theories. I developed an adequate measure of female status (i.e. resource control), and explored its effects on female preferences in an online survey (Chapter 3), a mail-shot survey (Chapter 4), and a sample of non-industrial societies (Chapter 5). Results implicated a role of constraints on women in the expression of female-typical preferences. In an experimental manipulation of female perceptions of their status, results enabled greater confidence in the attribution of causal direction to relationships (Chapter 6). In Chapter 7, I explored the conditions under which the relationships of interest occurred. In Chapter 8, to further explore the origin models I investigated the effects of resource control on the magnitudes of sex differences in preferences. In Chapter 9, I explored relationships between a characteristic more closely related to the male gender role (i.e. apparent intelligence) and femininity in female faces. Women who were considered to look more intelligent were perceived as less feminine. In Chapter 10, I investigated the effects of reproductive strategy on mate preferences. Results were consistent with evolutionary models of behaviour. I argue that “status” is a multidimensional construct, and that its effects on mate preferences are complex, that while results were generally more consistent with an evolutionary than the biosocial model, integration of models would provide greater insight into human mate preferences. 2007-01-01T00:00:00Z Moore, Fhionna R. Mate preferences provide an opportunity to explore the validity of evolutionary and social role origin theories of sex differences in human behaviour. In evolutionary models, preferences are sex-specific adaptive responses to constraints to reproductive success. In social role models, sex differences arise from the allocation of men and women to different gender roles. I explored the effects of the status of women on preferences to assess the validity of the origin theories. I developed an adequate measure of female status (i.e. resource control), and explored its effects on female preferences in an online survey (Chapter 3), a mail-shot survey (Chapter 4), and a sample of non-industrial societies (Chapter 5). Results implicated a role of constraints on women in the expression of female-typical preferences. In an experimental manipulation of female perceptions of their status, results enabled greater confidence in the attribution of causal direction to relationships (Chapter 6). In Chapter 7, I explored the conditions under which the relationships of interest occurred. In Chapter 8, to further explore the origin models I investigated the effects of resource control on the magnitudes of sex differences in preferences. In Chapter 9, I explored relationships between a characteristic more closely related to the male gender role (i.e. apparent intelligence) and femininity in female faces. Women who were considered to look more intelligent were perceived as less feminine. In Chapter 10, I investigated the effects of reproductive strategy on mate preferences. Results were consistent with evolutionary models of behaviour. I argue that “status” is a multidimensional construct, and that its effects on mate preferences are complex, that while results were generally more consistent with an evolutionary than the biosocial model, integration of models would provide greater insight into human mate preferences. http://hdl.handle.net/10023/162 Abstract: The overarching purpose of the studies presented in this report is the exploration of the uses of information theory and Bayesian inference applied to neural codes. Two approaches were taken: Starting from first principles, a coding mechanism is proposed, the results are compared to a biological neural code. Secondly, tools from information theory are used to measure the information contained in a biological neural code. Chapter 3: The REC model proposed by Harpur and Prager codes inputs into a sparse, factorial representation, maintaining reconstruction accuracy. Here I propose a modification of the REC model to determine the optimal network dimensionality. The resulting code for unfiltered natural images is accurate, highly sparse and a large fraction of the code elements show localized features. Furthermore, I propose an activation algorithm for the network that is faster and more accurate than a gradient descent based activation method. Moreover, it is demonstrated that asymmetric noise promotes sparseness. Chapter 4: A fast, exact alternative to Bayesian classification is introduced. Computational time is quadratic in both the number of observed data points and the number of degrees of freedom of the underlying model. As an example application, responses of single neurons from high-level visual cortex (area STSa) to rapid sequences of complex visual stimuli are analyzed. Chapter 5: I present an exact Bayesian treatment of a simple, yet sufficiently general probability distribution model. The model complexity, exact values of the expectations of entropies and their variances can be computed with polynomial effort given the data. The expectation of the mutual information becomes thus available, too, and a strict upper bound on its variance. The resulting algorithm is first tested on artificial data. To that end, an information theoretic similarity measure is derived. Second, the algorithm is demonstrated to be useful in neuroscience by studying the information content of the neural responses analyzed in the previous chapter. It is shown that the information throughput of STS neurons is maximized for stimulus durations of approx. 60ms. 2006-11-30T00:00:00Z Endres, Dominik M. The overarching purpose of the studies presented in this report is the exploration of the uses of information theory and Bayesian inference applied to neural codes. Two approaches were taken: Starting from first principles, a coding mechanism is proposed, the results are compared to a biological neural code. Secondly, tools from information theory are used to measure the information contained in a biological neural code. Chapter 3: The REC model proposed by Harpur and Prager codes inputs into a sparse, factorial representation, maintaining reconstruction accuracy. Here I propose a modification of the REC model to determine the optimal network dimensionality. The resulting code for unfiltered natural images is accurate, highly sparse and a large fraction of the code elements show localized features. Furthermore, I propose an activation algorithm for the network that is faster and more accurate than a gradient descent based activation method. Moreover, it is demonstrated that asymmetric noise promotes sparseness. Chapter 4: A fast, exact alternative to Bayesian classification is introduced. Computational time is quadratic in both the number of observed data points and the number of degrees of freedom of the underlying model. As an example application, responses of single neurons from high-level visual cortex (area STSa) to rapid sequences of complex visual stimuli are analyzed. Chapter 5: I present an exact Bayesian treatment of a simple, yet sufficiently general probability distribution model. The model complexity, exact values of the expectations of entropies and their variances can be computed with polynomial effort given the data. The expectation of the mutual information becomes thus available, too, and a strict upper bound on its variance. The resulting algorithm is first tested on artificial data. To that end, an information theoretic similarity measure is derived. Second, the algorithm is demonstrated to be useful in neuroscience by studying the information content of the neural responses analyzed in the previous chapter. It is shown that the information throughput of STS neurons is maximized for stimulus durations of approx. 60ms.