RT Journal Article
SR Electronic
T1 Male veterans with PTSD exhibit aberrant neural dynamics during working memory processing: an MEG study
JF Journal of Psychiatry and Neuroscience
JO J Psychiatry Neurosci
FD Canadian Medical Association
SP 251
OP 260
DO 10.1503/jpn.150058
VO 41
IS 4
A1 Timothy J. McDermott
A1 Amy S. Badura-Brack
A1 Katherine M. Becker
A1 Tara J. Ryan
A1 Maya M. Khanna
A1 Elizabeth Heinrichs-Graham
A1 Tony W. Wilson
YR 2016
UL http://jpn.ca/content/41/4/251.abstract
AB Background: Posttraumatic stress disorder (PTSD) is associated with executive functioning deficits, including disruptions in working memory. In this study, we examined the neural dynamics of working memory processing in veterans with PTSD and a matched healthy control sample using magnetoencephalography (MEG).Methods: Our sample of recent combat veterans with PTSD and demographically matched participants without PTSD completed a working memory task during a 306-sensor MEG recording. The MEG data were preprocessed and transformed into the time-frequency domain. Significant oscillatory brain responses were imaged using a beamforming approach to identify spatiotemporal dynamics.Results: Fifty-one men were included in our analyses: 27 combat veterans with PTSD and 24 controls. Across all participants, a dynamic wave of neural activity spread from posterior visual cortices to left frontotemporal regions during encoding, consistent with a verbal working memory task, and was sustained throughout maintenance. Differences related to PTSD emerged during early encoding, with patients exhibiting stronger α oscillatory responses than controls in the right inferior frontal gyrus (IFG). Differences spread to the right supramarginal and temporal cortices during later encoding where, along with the right IFG, they persisted throughout the maintenance period.Limitations: This study focused on men with combat-related PTSD using a verbal working memory task. Future studies should evaluate women and the impact of various traumatic experiences using diverse tasks.Conclusion: Posttraumatic stress disorder is associated with neurophysiological abnormalities during working memory encoding and maintenance. Veterans with PTSD engaged a bilateral network, including the inferior prefrontal cortices and supramarginal gyri. Right hemispheric neural activity likely reflects compensatory processing, as veterans with PTSD work to maintain accurate performance despite known cognitive deficits associated with the disorder.