Victimisation and eyewitness memory : exploring the effects of physiological and psychological factors

Abstract

This thesis presents research designed to explore the role of physiological and psychological factors in mediating the effects of victimisation upon eyewitness memory. A tripartite model of arousal and memory is proposed encompassing physiological, psychological and motivational mechanisms. In order to investigate the potential role of these mechanisms, three laboratory based studies and one archival study are presented. The results of the laboratory studies suggest that physiological arousal may not influence eyewitness memory. In contrast, whilst direct support for an influence of psychological arousal is not provided, the possibility that psychological arousal may be an important factor cannot readily be dismissed. From a methodological perspective, contrary to existing laboratory-based research concerning visually-induced arousal, the results of the laboratory studies suggest that personal involvement may be an important factor influencing memory. Furthermore, the third laboratory study found that, differences in memory for emotional and neutral material may be a function of inherent differences between the material rather than an influence of arousal. Finally, in order to compare and contrast laboratory based research with the performance of real witnesses, a field based study utilising closed-circuit television to assess eyewitness accuracy for action details was conducted. In line with Studies One and Two, victims and bystanders were not found to differ in their memory performance. This study provides direct support for existing field and archival research suggesting that real victims and bystanders tend to be highly accurate in their eyewitness accounts. Taken together, the results of the research presented in this thesis suggest that whilst physiological arousal may not be an important factor influencing eyewitness memory, psychological and motivational influences may be important when witnesses are personally involved with the target incident.