Sleep Deprivation Induces Acute Dissociation via Altered EEG Rhythms Expression and Connectivity.
The fragmented sleep, fragmented mind hypothesis has associated sleep disturbances and dissociative states in subjects with dissociative traits, as supported by neurophysiological theories of consciousness stating that altered states might result from an altered functional interaction among brain modules due to inefficient sleep processes. Irrespective of dissociative traits, it is conceivable that a labile sleep-wake cycle might fuel dissociative states such as derealization, depersonalization, and dissociative amnesia. To verify whether acute sleep loss can prompt dissociative states and to identify possible psychophysiological correlates, we evaluated dissociative experiences (by means of Phenomenology of Consciousness Inventory and Clinician Administered Dissociative State Scale) and resting state EEG features (band-wise spectral content and phase synchronization) after total sleep deprivation. After deprivation, participants reported increased perception of altered state of consciousness and dissociative experiences, and a decreased perception of cognitive control. Analyzing the psychophysiological correlates of dissociative states following deprivation, we observed the following results: the higher the prefrontal theta spectral content, the higher the depersonalization state and the lower the self-awareness; the higher the intensity of the dissociative experiences, the higher the synchronization increase in alpha, beta, and gamma bands; the higher the decrease of higher-order functions, the higher the synchronization in the aforementioned bands. Thus, acute sleep deprivation appears to fuel dissociative experiences by establishing a state of consciousness promoted by a higher large-scale synchronization at high frequencies.