During conscious states, the cortex operates near a mathematically specific critical point called the edge-of-chaos, the boundary between stability and chaos. Applying a modified 0-1 chaos test to ECoG and MEG recordings from humans and macaques, evidence suggests that unconscious states—such as generalized seizure and anesthesia—involve a shift of low-frequency cortical oscillations away from this critical point, disrupting information processing. Psychedelic states tune these oscillations closer to the critical point, potentially increasing information richness. Analysis of clinical EEG from patients with disorders of consciousness indicates that measuring proximity to this critical point may serve as a clinical index of consciousness.
During conscious states, the cortex's electrical activity operates near the edge-of-chaos critical point—the boundary between stability and chaos. Applying a new chaos test to ECoG and MEG recordings from humans and macaques across waking, seizure, anesthesia, and psychedelic states shows that unconsciousness shifts cortical dynamics away from this critical point, disrupting information processing. Psychedelics may enhance information-richness by tuning activity closer to this point. Analysis of EEG from patients with disorders of consciousness suggests that measuring proximity to the edge-of-chaos critical point could serve as a clinical biomarker of consciousness.