A comparison of memory for homicide, non-homicidal violence, and positive life experiences.

Defendants commonly claim amnesia for their criminal actions especially in cases involving extreme violence. While some claims are malingered or result from physiological factors, other cases may represent genuine partial or complete amnesia resulting from the psychological distress and/or extreme emotion associated with the perpetration of the crime. Fifty Canadian homicide offenders described their memories of their homicide, a non-homicide violent offense, and their most positive adulthood life experience. Self-reported and objective measures of memories for these events revealed that homicides were recalled with the greatest level of detail and sensory information. Although dissociative tendencies were associated with a self-reported memory loss, objective measures of memory quality did not reflect this perceived impairment, suggesting a failure of meta-memory. Recollections of positive life events were superior to those of non-homicidal violence, possibly due to greater impact and meaning attached to such experiences. Findings suggest that memory for homicide typically is enhanced by the powerful emotion associated with its perpetration.

Are memories for sexually traumatic events "special"? A within-subjects investigation of trauma and memory in a clinical sample.

According to a long-standing clinical tradition, sexually traumatic experiences are processed and recalled differently from other experiences, often leading to memory impairment. In this study, we compared the characteristics of traumatic memories for sexual violence and two other types of emotional experiences. N=44 women recruited from a local sexual trauma agency were asked to recall and describe three autobiographical events: sexual abuse/assault, a non-sexual trauma, and a positive emotional event. The characteristics of the three memory types were compared on both subjective and objective measures. Further, the potential influences of level of traumatic impact and dissociation were assessed. Results indicated that memories for sexual trauma were not impaired or fragmented relative to other memories. Instead, memories for sexual trauma were associated with a remarkably high level of vividness, detail, and sensory components. Further, high levels of traumatic impact were not associated with memory impairment. Implications for the ongoing traumatic memory debate are discussed.

The scars of memory: a prospective, longitudinal investigation of the consistency of traumatic and positive emotional memories in adulthood.

We conducted a prospective study with individuals who first described their memories of both a recent traumatic and a highly positive emotional experience in 2001-2002. Of the 49 subjects interviewed after 3 months, 29 were re-interviewed after 3.45 to 5.0 years. Subjects answered questions from a 12-item consistency questionnaire (maximum possible score of 36), rated the qualities of their memories, and completed questionnaires concerning the impact of the trauma. Results indicated that traumatic memories (including memories for violence) were highly consistent (M= 28.04) over time relative to positive memories (M= 17.75). Ratings of vividness, overall quality, and sensory components declined markedly for positive memories but remained virtually unchanged for traumatic memories. The severity of traumatic symptoms diminished over time and was unrelated to memory consistency. These findings contribute to understanding of the impact of trauma on memory over long periods.