Brain
March 6, 2021
Joel Frohlich, Daniel Toker, Martin M. Monti
204 citations
High amplitude delta waves (1–4 Hz) in EEG have long been considered a marker of unconsciousness, observed during deep sleep, anesthesia, seizures, and disorders of consciousness. However, recent studies report prominent delta activity during conscious states, including Angelman syndrome, epilepsy, propofol anesthesia with behavioral responsiveness, postoperative delirium, dreaming, and psychedelic states. Older clinical reports also describe awake, conscious patients with high amplitude delta in Rett syndrome, Lennox-Gastaut syndrome, schizophrenia, mitochondrial diseases, hepatic encephalopathy, and non-convulsive status epilepticus.
eLife
January 5, 2024
Daniel Toker, Eli Müller, Hiroyuki Miyamoto et al.
21 citations
Bidirectional communication between the cortex and thalamus via a specific cross-frequency channel is linked to conscious states. In humans, mice, and rats, low-frequency waves (1–13 Hz) sent from either the cortex or thalamus are consistently encoded by the other region using high gamma waves (52–104 Hz). This cross-frequency communication is diminished during propofol-induced unconsciousness and generalized spike-and-wave seizures, but enhanced by the psychedelic 5-MeO-DMT. Numerical simulations and neural recordings suggest these changes are mediated by shifts in thalamocortical electrodynamics toward or away from edge-of-chaos criticality, offering a mathematical framework for disrupted information transfer during unconsciousness.
bioRxiv Preprint Server
February 22, 2023
Daniel Toker, Eli Müller, Hiroyuki Miyamoto et al.
3 citations
preprint
Consciousness depends on bidirectional communication between the cortex and thalamus. A specific pattern of cross-frequency communication—low-frequency waves (1.5–13 Hz) from one region encoded as high gamma waves (50–100 Hz) in the other—is present during conscious states in humans, mice, and rats. This communication diminishes during propofol-induced anesthesia and generalized spike-and-wave seizures, but is enhanced by the psychedelic 5-MeO-DMT. Numerical simulations and neural recordings show that these changes are mediated by shifts in thalamocortical dynamics toward or away from edge-of-chaos criticality, the phase transition between stability and chaos. The findings offer a mathematically defined framework linking thalamic-cortical communication to consciousness.