Relaxed Beliefs After Psychedelics: From Sensory Processing to Mystical States
December 1, 2024 Jacobs, Chloe Lily West
Recent use of 5-HT2A psychedelics such as psilocybin and LSD weakens top-down modulation and increases bottom-up signaling in visual cortical circuits, shifting the balance of information flow. In human participants, this resulted in reduced express saccade production and a generalization of prediction errors. Mouse studies showed similar alterations, with enhanced bottom-up drive persisting for days. These findings support the Relaxed Beliefs under Psychedelics (ReBUS) model. 5-MeO-DMT, a 5-HT1A-selective psychedelic, produced distinct effects: altered saccade production but unaltered deviance detection, and a tendency toward hypo-connectivity states in resting-state brain networks, contrasting with the hyper-connectivity states seen after 5-HT2A use. The dissertation also proposes the ReBUS model as a framework for understanding mystical experiences beyond psychedelics and emphasizes the role of post-acute context in consolidating belief changes.