Electrophysiological signatures of posttraumatic stress disorder (PTSD) reflect frequency-specific alterations in large scale cortical coordination during resting state magnetoencephalography (MEG).

Posttraumatic stress disorder (PTSD) is increasingly conceptualized as involving stress-related alterations in large-scale neural systems supporting memory-related processes, alongside broader cognitive and emotional regulation. The present study examined resting-state, frequency-specific oscillatory activity and functional connectivity in PTSD using magnetoencephalography (MEG). Guided by the tri-network model, we tested whether PTSD would be associated with altered cortical oscillatory dynamics and reduced synchrony within and between the default mode, salience, and central executive networks, systems suggested to be implicated in memory and cognitive control. Eyes-open resting-state MEG data were acquired from trauma-exposed Canadian Armed Forces (CAF) members and Veterans with PTSD (n = 57) and trauma-exposed control (TEC) members and Veterans (n = 54). PTSD showed increased delta-band activity (1-3 Hz) in occipital, parietal, and temporal regions, alongside reduced gamma-band activity above 30 Hz in frontal and limbic regions. Reduced alpha-band synchrony (8-14 Hz) was also seen within and between regions of the default mode, salience, and central executive networks. These findings indicate disrupted temporal coordination across cortical systems that support memory function and cognitive control processes in PTSD. Such alterations may reflect impaired integration and regulation of internally generated information, consistent with core clinical features of PTSD. Resting-state MEG measures, therefore, provide frequency-specific markers of large-scale neural coordination differences associated with trauma-related psychopathology.