Psilocybin asymmetrically modulates outcome-based choice and cortical processing under uncertainty

Area of Science:

• Neuroscience
• Psychopharmacology
• Computational Psychiatry

Background:

• Emerging research suggests psilocybin's therapeutic potential for psychiatric disorders.
• Neural mechanisms underlying psilocybin's effects, particularly in meta-learning and cognitive flexibility, are being investigated.
• Rodent models are limited in studying the subjective psychedelic experience but can quantify neural processes during drug exposure.

Purpose of the Study:

• To computationally model and record neural activity in the medial prefrontal cortex during psilocybin exposure.
• To characterize how psilocybin affects value-based probabilistic choice tasks.
• To understand the impact of psilocybin on reinforcement learning and neural representations of outcomes.

Main Methods:

• Utilized computational modeling and single-unit recordings in rodents.
• Administered psilocybin during a value-based probabilistic choice task.
• Analyzed medial prefrontal cortex activity and behavioral choice selection.

Main Results:

• Psilocybin improved choice selection in uncertain environments.
• Observed bidirectional shifts in reinforcement learning rates: enhanced updating from rewards, reduced updating from punishments.
• Neural encoding showed enhanced representation of rewarded outcomes and diminished representation of unrewarded outcomes.

Conclusions:

• Psilocybin enhances choice selection in uncertainty by modulating reinforcement learning.
• The drug alters cortical coding, favoring learning from positive experiences.
• Findings suggest psilocybin's potential to improve cognitive flexibility and learning in psychiatric contexts.