Pilot Neuroimaging Study in Civilian Trauma Survivors

Abstract

Despite its hypothesized role in the etiology of posttraumatic stress disorder (PTSD), little research has investigated neural correlates of episodic memory impairment in trauma survivors. This pilot study utilized a correlational design to investigate the association between PTSD symptom severity, hippocampal volume, episodic memory, and brain activation during the Remember-Know task. Eleven non-medicated, right-handed survivors of civilian trauma participated in the study. Significant positive correlations were found between PTSD symptom severity and the activation of brain areas implicated in the episodic recognition network such as hippocampus, precuneus, and occipital gyrus. Higher PTSD symptoms were also significantly negatively correlated with brain activations in areas associated with episodic memory but also visuospatial attention such as the superior parietal lobule and the supramarginal gyrus. The pattern of results indicates specific alterations in the recruitment of the episodic memory network, possibly with a focus on internal mental imagery at the cost of integration between internal processes and external visuospatial online monitoring.