Source-level analysis of RS α oscillations isolated α (power and connectivity) deficits in the DMN and VC in PTSD, especially during strong visual stimulation. In support of our first hypothesis, α deficits in the DMN, the PTSD group demonstrated reduced α power in the posterior DMN hub (the PCC) at both S-RS and M-RS as well as the anterior hub (the mPFC) at M-RS, accompanied by reduced DMN (PCC→mPFC) α-frequency connectivity at M-RS. In support of the second hypothesis, α deficits in the VC, the PTSD group exhibited reduced α power in the VC at both states. Importantly, joining α deficits in the two neural systems, diminished α-frequency connectivity from the VC to the DMN was observed in the PTSD group at M-RS. Finally, α power deficits in the DMN and VC directly correlated with symptom severity of hypervigilance. Therefore, linking anomalies in DMN and α activity in PTSD, the current results indicate interrelated α deficits in the DMN and VC, implicating visual-cortex-DMN α dysrhythmia in the neuropathology of PTSD.
