Psychedelics Relax Priors and Reshape Orbitofrontal Dynamics
Abstract
Psychedelics such as psilocybin and ketamine are gaining attention as rapid-acting treatments for psychiatric disorders, yet the mechanisms by which they alter cognition remain unclear. A key hypothesis—the REBUS model—proposes that psychedelics relax high-level priors, allowing bottom-up sensory information to exert greater influence over perception and behavior. Here, we test this model in mice performing a free-response perceptual decision-making task that disambiguates prior-driven and sensory-driven decision strategies. Acute administration of psilocybin or ketamine significantly slowed decision times and improved accuracy. Behavioral modeling that combined drift diffusion and GLM-HMM frameworks revealed that these changes were mediated by increased decision thresholds and a marked shift into sensory-engaged cognitive states. Whole-brain c-Fos mapping identified a distributed decision-making network, with psychedelics selectively modulating cortical and subcortical nodes. Calcium imaging in the orbitofrontal cortex (OFC)—a key region for integrating priors and sensory inputs—revealed preserved decision-related selectivity under psychedelics, while exhibiting reduced neuronal correlations—population-level signatures of weakened top-down influence and relaxed priors. Together, these results provide circuit-level support for the REBUS model, showing that psychedelics reconfigure brain-wide and local dynamics to promote more deliberate, flexible, and sensory-driven decision policies.
Topics & conditions
Detected automatically by Psychedelic Commons from the title and abstract, not labels from the source. They may be incomplete.
Psychedelic Commons aggregates metadata from open sources and links back to the original. Rights remain with the authors and publishers. Something wrong with this record? Report a problem.