New research suggests exposure to trauma makes it more difficult for the brain to suppress unwanted emotional memories. The experience of trauma appears to lead to neural and behavioral disruptions in the brain that may contribute to the development of post-traumatic stress disorder (PTSD).
PTSD is characterized by intense reliving of the trauma that is repetitive, intrusive and incapacitating. The inability to suppress unwanted memories may be a strong contributor to the behavioral manifestation of PTSD.
Prior studies have shown that healthy individuals can actively suppress emotional memories while individuals with PTSD frequently experience unwanted memories of their traumatic experiences, even when making concentrated efforts to avoid them.
In the new study, researchers addressed the behavioral and neural effects of memory suppression among individuals with PTSD – a perspective that has been underreported in the past. Investigators used functional magnetic resonance imaging to examine memory suppression in three groups: those with PTSD; those who experienced trauma without PTSD and controls with no trauma exposure or PTSD.
Their findings, which appear in the Journal of Psychiatric Research, are meaningful as trauma-exposed participants (regardless of PTSD status) were less likely to successfully suppress memory than non-trauma-exposed controls.
“Neuroimaging data revealed that trauma-exposed individuals showed reduced activation in the right middle frontal gyrus, a critical region for memory suppression, during a memory suppression task and were less likely to successfully suppress memory compared to non-trauma exposed individuals.
These results suggest that trauma exposure is associated with neural and behavioral disruptions in memory suppression and point to the possibility that difficulty in active suppression of memories may be just one of several likely factors contributing to the development of PTSD,” explained lead author Danielle R. Sullivan, PhD, Boston University School of Medicine.
Sullivan is also affiliated with the National Center for PTSD, and VA Boston Healthcare System.