Alpha Hypersynchrony and Atypical Memory Processes in Soldiers with Post-Traumatic Stress Disorder

Benjamin T. Dunkley, Elizabeth W. Pang, Paul A. Sedge, Rakesh Jetly and Margot J. Taylor

Abstract

Post-traumatic stress disorder (PTSD) is a psychiatric disorder that is associated with a variety of cognitive sequelae, including disorders of memory. We hypothesised that alterations in functional connectivity in PTSD, mediated by neural synchronisation, may be associated with such deficits. Using magnetoencephalography (MEG), we identified elevated alpha-band (8-14 Hz) phase synchronisation in soldiers with PTSD during working memory and delayed recognition tasks that included war-related and neutral pictures. Performance for the PTSD group matched controls on the working memory task, and this was accompanied by increases in long-range connectivity in the alpha-band during encoding, left-dominant, at 50-150 ms and during recognition at 150-250 ms involving temporal and frontal brain regions. In the delayed recognition task, performance was reduced in the PTSD group compared to controls for neutral, but not war-related images. Elevated alpha-band phase synchronisation was observed in the PTSD group in a right-dominant network of front-temporal and deep grey matter regions for both types of stimuli between 50-150 ms. The literature posits alpha phase dynamics are involved in working memory; our results suggest that atypical alpha synchronisation is related to memory-related sequelae in PTSD, one of the more ubiquitous cognitive comorbidities observed in this disorder.

Published on: June 13, 2016
doi: 10.17756/jnpn.2016-007
Citation:  Dunkley BT, Pang EW, Sedge PA, Jetly R, Taylor MJ. 2016. Alpha Hypersynchrony and Atypical Memory Processes in Soldiers with Post-Traumatic Stress Disorder. J Neuroimaging Psychiatry Neurol 1(2): 54-63.

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