Fig. 1.

Hypothesized relationship between consciousness, edge-of-chaos criticality, and cortical information processing. We suggest that the electrodynamics of the cortex may be poised near the edge-of-chaos critical point during conscious states and transition away from this specific critical point during unconscious states. According to this hypothesis, transitions of cortical electrodynamics away from this critical point—either into the chaotic phase (leading to dynamical instability) or into the periodic phase (leading to hyperstability)—should disrupt cortical information processing and induce unconsciousness. In other words, we should expect to see an inverse-U relationship between chaoticity and information processing in the cortex, with cortical dynamics during conscious states near the top of this inverse U (i.e., in the near-critical, information-rich regime), and we should moreover expect to see cortical dynamics during unconscious states at either the bottom right of this inverse U (i.e., the unstable, information-poor regime) or at the bottom left of this inverse U (i.e., the hyperstable, information-poor regime) (1, 2, 22). Such an inverse-U relationship between chaoticity and information processing has been observed in many other dynamical systems (6–9), but remains to be empirically observed in the brain.