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.
When people view a steady, unchanging image, the brain's sensory regions maintain a stable representation of what is being seen, even as overall neural activity changes over time. In contrast, frontal and parietal brain areas only represent the image's content briefly at the moment it first appears. These findings, based on intracranial recordings from ten people with epilepsy, suggest that sustained conscious perception may depend on sensory cortex, while discrete perceptual updates may rely on frontoparietal regions.
Activity in the prefrontal cortex (PFC) is critical for conscious perception, contradicting claims that PFC lesions do not affect subjective experience, that PFC activity does not reflect perceptual content, or that its role is solely due to task-related reporting. Empirical evidence shows PFC is essential for subjective experience in perception, not just for performing visual tasks. Confusing these two aspects can lead to misunderstandings.