The entropic brain: a theory of conscious states informed by neuroimaging research with psychedelic drugs
Frontiers in Human Neuroscience January 1, 2014 Robin Carhart‐Harris, Robert Leech, Peter J. Hellyer et al. 1,289 citations
Entropy, a measure of uncertainty or disorder, is applied to brain function and consciousness, focusing on the psychedelic state induced by psilocybin. The psychedelic state is considered a primary or primitive state of consciousness, characterized by elevated entropy in brain function, including a greater repertoire of functional connectivity motifs that form and fragment over time. This suggests primary states may exhibit criticality, a transition zone between order and disorder. Normal waking consciousness suppresses entropy, operating just below criticality, which constrains cognition and enables metacognitive functions like reality-testing and self-awareness. Entry into primary states involves collapse of default-mode network activity and decoupling from medial temporal lobes. These hypotheses can be tested by comparing brain activity in REM sleep, early psychosis, normal waking consciousness, and anesthesia.