Neural oscillations while remembering traumatic memories in post-traumatic stress disorder.

OBJECTIVE:The current study investigated the oscillatory brain activity of PTSD patients during directed and imaginal exposure to the traumatic memory using magnetoencephalography (MEG), in a paradigm resembling exposure therapy. METHODS:Brain activity of healthy trauma-exposed controls and PTSD participants was measured with MEG as they listened to individualized trauma narratives as well as to a neutral narrative and as they imagined the narrative in detail. Source localization analysis by frequency bands was conducted in order to map neural generators of oscillatory activity. RESULTS:Elicitation of traumatic memories resulted in a distinct neural pattern in PTSD patients compared to healthy trauma-exposed individuals. In response to trauma scripts PTSD patients showed increases in high-gamma band power in visual areas, increased frontal and temporal theta as well as prefrontal alpha and medial temporal beta power relative to neutral scripts. CONCLUSIONS:Results suggest that when recollecting and imagining traumatic memories PTSD patients attempt to engage control or inhibition mechanisms. However, these are either not successfully recruited or inefficient leading to heightened responses and recollection. SIGNIFICANCE:Investigating the oscillatory neural dynamics of PTSD patients can help us better understand the processes underlying trauma re-experiencing.