The Administration of Ketamine Is Associated with Dose-Dependent Stabilization of Cortical Dynamics in Humans.
The Journal of neuroscience : the official journal of the Society for Neuroscience May 14, 2025 Diego G Dávila, Andrew McKinstry-Wu, Max B Kelz et al. 5 citations
During wakefulness, people respond to external stimuli, while in dreams or drug-induced dissociated states, vivid internal experiences occur with reduced perception of the outside world. The brain's activity near a critical point between damped and exploding oscillations is linked to conscious experience, and this signature appears in both normal wakefulness and dissociative states but not in dreamless sleep or anesthesia. Using high-density EEG in human male volunteers given escalating ketamine doses, activity became progressively more stable, especially at higher frequencies, as dissociative symptoms increased. This stabilization correlated with reduced ability to perceive external stimuli, not with conscious experience itself. Combining statistical and dynamical measures of criticality may help distinguish wakefulness, dissociation, and unconsciousness.