Investigating the Memory Amplification Effect: Understanding the Role of Reality-Monitoring Errors

Author: Jacinta Oulton

Oulton, Jacinta, 2018 Investigating the Memory Amplification Effect: Understanding the Role of Reality-Monitoring Errors, Flinders University, College of Education, Psychology and Social Work

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Victims of traumatic experiences—such as war veterans—are often inconsistent when remembering stressful past events. Interestingly, field research suggests that these inconsistencies typically follow a particular pattern, whereby victims remember being exposed to additional events (e.g., experiencing sniper fire, sitting with the dying) over time. This pattern of findings—termed the “memory amplification effect”—is positively associated with the re-experiencing symptoms of post-traumatic stress disorder (PTSD), such as involuntary memories, thoughts or images about the trauma. Given the relationship between re-experiencing symptoms and memory amplification, one possibility is that memory amplification reflects a failure in reality monitoring. More specifically, as memory traces fade over time, trauma victims may erroneously incorporate imagined details about the trauma—that are introduced via re-experiencing symptoms—with what actually happened. Indeed, supporting this explanation, we know that trauma victims sometimes experience involuntary cognitions that are not accurate depictions of the trauma as it actually happened. Importantly, however, no research to date has investigated this explanation for memory amplification. Thus, the broad objective of this thesis was to empirically examine whether reality-monitoring errors contribute to the memory amplification effect. To this end, across several investigations in this thesis, I tested the key assumptions underlying the reality-monitoring proposal. Specifically, I investigated whether (1) re-experiencing symptoms are associated with changes in memory distortion and/or response biases, (2) victims of real-life traumatic experiences with heightened PTSD symptoms experience involuntary cognitions that include imagined details and are experienced similarity to involuntary memories, and (3) experimentally manipulating the imagination of new (non-experienced) trauma details has a causal effect on memory amplification. Consistent with reality-monitoring proposal, my findings suggest that the re-experiencing symptoms of PTSD are associated with an increased tendency to endorse trauma exposure over time, and an increase in false traumatic memories. Further, my results show that victims of trauma with heightened PTSD symptomology are more susceptible to involuntary cognitions that included imagined details—“involuntary elaborative cognitions”—relative to trauma victims with minimal PTSD symptoms. Importantly however, because we were unsuccessful in manipulating involuntary elaborative cognitions specifically, we observed no direct evidence for the reality-monitoring account. But, taken together, the findings from this thesis provide some preliminary support for the reality-monitoring proposal and suggest that future investigation of the precise mechanism underlying the memory amplification and intrusions relationship is certainly warranted. In particular, these findings suggest that examination of the strategies participants adopt when determining whether an event is experienced or non-experienced would be useful, as well as investigating the role of individual difference factors, including trait ability to internally generate vivid mental imagery and meta-cognitive beliefs about memory.

Keywords: memory, trauma, PTSD

Subject: Psychology thesis

Thesis type: Doctor of Philosophy
Completed: 2018
School: College of Education, Psychology and Social Work
Supervisor: Melanie Takarangi