Mentalizing under influence: abnormal dependence on prior expectations in patients with schizophrenia

Area of Science:

• Cognitive Neuroscience
• Psychiatry
• Social Cognition

Background:

• Impaired mental state appreciation is a key cognitive deficit in schizophrenia, contributing to social dysfunction.
• The underlying mechanisms of these impairments and their clinical links remain unclear.
• Mentalizing, the ability to infer intentions, is crucial for social interaction.

Purpose of the Study:

• To investigate how abnormal interactions between sensory evidence and prior expectations affect mentalizing in schizophrenia.
• To determine if mentalizing deficits are generalized or specific to certain types of intentions.
• To explore the relationship between these interaction patterns and schizophrenia symptom dimensions.

Main Methods:

• Designed four tasks to assess inference of basic/superordinate and non-social/social intentions.
• Manipulated sensory evidence (movement kinematics) and prior expectations in each task.
• Analyzed the interaction patterns between sensory evidence and prior expectations in relation to performance and symptoms.

Main Results:

• Schizophrenia patients correctly inferred non-social basic intentions.
• Patients struggled with non-social superordinate and all social intentions (basic and superordinate).
• Abnormal interactions observed: over-reliance on prior expectations (linked to positive symptoms) or sensory evidence (linked to negative symptoms).

Conclusions:

• Mentalizing deficits in schizophrenia are specific, not generalized.
• Abnormal integration of sensory evidence and prior expectations underlies these specific deficits.
• Distinct patterns of integration correlate with positive and negative symptom severity, suggesting a disturbed Bayesian inferential mechanism.