Trauma & Memory

Research on the Effect of Trauma on Memory

Research has shown that traumatized individuals respond by using a variety of psychological mechanisms. One of the most common means of dealing with the pain is to try and push it out of awareness. Some label the phenomenon of the process whereby the mind avoids conscious acknowledgment of traumatic experiences as dissociative amnesia .  Others use terms such as repression dissociative state traumatic amnesia, psychogenic shock, or motivated forgetting .  Semantics aside, there is near-universal scientific acceptance of the fact that the mind is capable of avoiding conscious recall of traumatic experiences.

Research Addressing

FAQ

  • Summary of Research Examining the Prevalence of Full or Partial  Dissociative Amnesia for Traumatic Events — Studies show that a period of either partial or full amnesia is reported by between 30 and 90% of adult victims of childhood sexual abuse. Moreover, no study that has looked for evidence of traumatic or dissociative amnesia after child sexual abuse failed to find it.
  • The Evidence for Dissociative Amnesia – A Review of 100 years of Research
  • Freyd, J. J. (2003). Memory for abuse: What can we learn from a prosecution sample? Journal of Child Sexual Abuse, 12, 97-103.
  • This commentary responds to an article by Goodman et al. (2003) where 81% of adults with documented abuse during childhood reported the abuse on follow-up. This proportion that is somewhat higher than in some previously published prospective studies assessing memory for abuse. Freyd notes that many factors distinguish prospective prosecution samples (adults who were as children abused and then involved in child abuse prosecution cases) from adults who were as children abused and who were not subsequently involved in prosecution. Namely that these children were believed, protected, supported, and legitimated. Given that these should all contribute to memorability and thwart forgettability, Freyd notes that it is actually quite striking that 19% of the participants failed to disclose the abuse when interviewed later.

Responses:

  • Betrayal-Trauma Theory: — Professor of cognitive psychology Jennifer Freyd created a useful web page explaining her theory of why children forget suppress awareness of some traumas and not others.
  • Depue, B. E., Curran, T., & Banich, M. T. (2007). Prefrontal Regions Orchestrate Suppression of Emotional Memories via a Two-Phase Process. Science, 317 (5835), 215-219.Whether memories can be suppressed has been a controversial issue in psychology and cognitive neuroscience for decades. We found evidence that emotional memories are suppressed via two time-differentiated neural mechanisms: (1) an initial suppression by the right inferior frontal gyrus over regions supporting sensory components of the memory representation (visual cortex, thalamus), followed by (2) right medial frontal gyrus control over regions supporting multimodal and emotional components of the memory representation (hippocampus, amygdala), both of which are influenced by fronto-polar regions. These results indicate that memory suppression does occur and, at least in nonpsychiatric populations, is under the control of prefrontal regions.
  • See also, Putting a Lid on Bad Memories:The Mechanics of Memory Suppression

More information on false memory claims: