Discrete Deviations in Emotional Processing and Regulation Among Individuals With PTSD: Evidence of P300 and LPP...

Event-related potentials (ERPs) have been widely investigated to uncover associated neural deficits characterizing PTSD. However, existing studies investigating deviations in ERP components in PTSD compare differences among individuals with PTSD and healthy controls with no trauma history. Furthermore, associations between ERPs and PTSD symptom clusters are rarely investigated. Understanding how reliable neural potentials differ among individuals who develop versus do not develop PTSD following trauma could inform on the pathophysiology of the disorder and potential neural risk markers that further our understanding of its etiology. The present study extracted neural activity reflecting various stages of emotional processing (i.e., P300, early LPP, and late LPP) during an emotional regulation task to evaluate differences in emotional reactivity and regulation among individuals with PTSD (n = 49) versus individuals who were exposed to a traumatic event but did not develop PTSD (n = 85). Individuals with PTSD exhibited reduced P300 amplitudes while suppressing emotional experience to negative images and reduced early LPP across emotion regulation conditions. Furthermore, blunted suppress P300 and higher enhance P300 were both uniquely associated with PTSD. Symptom cluster analyses revealed that deficits in suppress P300 are attributed to avoidance symptoms, while larger P300 are attributed to hyperarousal symptoms. Results demonstrate that individuals with PTSD are characterized by deficits in early emotional expression and regulation (i.e., enhance and suppress P300) compared to those who did not develop the disorder. These deficits are potentially reflecting symptoms of hyperarousal and avoidance, respectively.