PT  - JOURNAL ARTICLE
AU  - Daniel Toker
AU  - Ioannis Pappas
AU  - Janna D. Lendner
AU  - Joel Frohlich
AU  - Diego M. Mateos
AU  - Suresh Muthukumaraswamy
AU  - Robin Carhart-Harris
AU  - Michelle Paff
AU  - Paul M. Vespa
AU  - Martin M. Monti
AU  - Friedrich T. Sommer
AU  - Robert T. Knight
AU  - Mark D’Esposito
TI  - Consciousness is supported by near-critical cortical electrodynamics
AID  - 10.1101/2021.06.10.447959
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.06.10.447959
4099  - http://biorxiv.org/content/early/2021/06/11/2021.06.10.447959.short
4100  - http://biorxiv.org/content/early/2021/06/11/2021.06.10.447959.full
AB  - Mounting evidence suggests that during conscious states, the electrodynamics of the cortex are poised near a critical point or phase transition, and that this near-critical behavior supports the vast flow of information through cortical networks during conscious states. Here, for the first time, we empirically identify the specific critical point near which conscious cortical dynamics operate as the edge-of-chaos critical point, or the boundary between periodicity/stability and chaos/instability. We do so by applying the recently developed modified 0-1 chaos test to electrocorticography (ECoG) and magne-toencephalography (MEG) recordings from the cortices of humans and macaques across normal waking, generalized seizure, GABAergic anesthesia, and psychedelic states. Our evidence suggests that cortical information processing is disrupted during unconscious states because of a transition of cortical dynamics away from this critical point; conversely, we show that psychedelics may increase the information-richness of cortical activity by tuning cortical electrodynamics closer to this critical point. Finally, we analyze clinical electroencephalography (EEG) recordings from patients with disorders of consciousness (DOC), and show that assessing the proximity of cortical electrodynamics to the edge-of-chaos critical point may be clinically useful as a new biomarker of consciousness.Significance Statement What changes in the brain when we lose consciousness? One possibility is that the loss of consciousness corresponds to a transition of the brain’s electric activity away from edge-of-chaos criticality, or the knife’s edge in between stability and chaos. Recent mathematical developments have produced novel tools for testing this hypothesis, which we apply for the first time to cortical recordings from diverse brain states. We show that the electric activity of the cortex is indeed poised near the boundary between stability and chaos during conscious states and transitions away from this boundary during unconsciousness, and that this transition disrupts cortical information processing.Competing Interest StatementThe authors have declared no competing interest.