Examining belief and confidence in schizophrenia

Area of Science:

• Cognitive neuroscience
• Psychiatry
• Computational modeling

Background:

• Psychotic disorders are characterized by delusional beliefs resistant to contrary evidence.
• Delusions arise from impaired integration of new and old evidence in cognitive models.
• A computational model of belief formation was tested using a Rock Paper Scissors game.

Purpose of the Study:

• To investigate cognitive mechanisms underlying delusional belief formation in psychosis.
• To model how individuals integrate evidence to form and report confidence in beliefs.
• To compare belief formation strategies between individuals with schizophrenia and healthy controls.

Main Methods:

• Participants (schizophrenia and controls) played an interactive Rock Paper Scissors game under time pressure.
• Behavior was modeled using leaky integrator and temporal difference computational methods.
• The model assessed evidence integration for strategy formation and confidence reporting.

Main Results:

• Individuals with schizophrenia failed to model opponent's play, indicating poor use of existing evidence.
• A 'jumping to conclusions' bias was observed, with premature confidence in strategies.
• Schizophrenia group showed impaired weighting of old versus new evidence.

Conclusions:

• Delusional belief formation may involve impaired behavioral pattern modeling and metacognitive overconfidence.
• Individuals with schizophrenia struggle to appropriately utilize past evidence when learning.
• Metacognitive deficits in schizophrenia may involve overemphasizing recent rewards for belief valuation.