A spontaneous dissociative episode during an EEG experiment

Area of Science:

• Neuroscience
• Cognitive Psychology
• Psychiatry

Background:

• Depersonalization is a dissociative symptom characterized by detachment from oneself.
• Understanding the neural correlates of depersonalization is crucial for developing targeted interventions.

Purpose of the Study:

• To investigate the electroencephalogram (EEG) correlates of an unexpected depersonalization episode.
• To analyze the spatiotemporal dynamics of brain activity during depersonalization.

Main Methods:

• An unexpected depersonalization episode was recorded during an electroencephalogram (EEG) study.
• Source activity in canonical frequency bands was analyzed across four periods relative to subjective experience reports.
• Functional connectivity was assessed in relation to neural activity.

Main Results:

• Delta and theta power decreased across all periods, unrelated to reported events.
• Following depersonalization, increases in theta, alpha, beta, and gamma power were observed in specific cortical regions, including bilateral fronto-polar and medial prefrontal cortex, left insula, and right secondary visual cortex.
• A high-frequency functional network with a hub in the left insula correlated with increased gamma power in the inferior left cortex.

Conclusions:

• Increased gamma and other frequency band power in specific frontal and insular regions may reflect the generation of predictive models to re-establish a sense of self.
• These findings provide insights into the neural mechanisms underlying dissociation and depersonalization.