Psychedelics and schizophrenia: Distinct alterations to Bayesian inference

Area of Science:

• Neuroscience
• Psychiatry
• Computational Biology

Background:

• Schizophrenia and psychotomimetic drug states share some properties but differ fundamentally.
• Understanding these altered states of consciousness is crucial for mental health research.
• LSD and ketamine are being explored for therapeutic potential in mental illnesses.

Purpose of the Study:

• To compare neural dynamics in schizophrenia with those induced by LSD and ketamine in healthy volunteers.
• To investigate differences in brain information processing between schizophrenia and drug-induced states.
• To model these neural changes using a predictive processing framework.

Main Methods:

• Resting-state M/EEG recordings were used to observe neural dynamics.
• Analysis included neural signal diversity and transfer entropy.
• A computational model based on Bayesian inference and predictive processing was employed.

Main Results:

• Both schizophrenia and drug-induced states showed increased neural signal diversity.
• Schizophrenia exhibited increased front-to-back brain transfer entropy.
• LSD and ketamine showed an overall reduction in transfer entropy.

Conclusions:

• Neural dynamics in schizophrenia and drug-induced states diverge in information flow patterns.
• Altered Bayesian inference, specifically prior precision (drugs) versus sensory precision (schizophrenia), underlies these differences.
• Findings offer insights into consciousness and potential therapeutic strategies for mental health conditions.