Dynamic causal modeling of eye gaze processing in schizophrenia

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Science

Background:

• Abnormal eye gaze perception is linked to schizophrenia symptoms and social deficits.
• Brain network mechanisms underlying these gaze abnormalities remain poorly understood.
• This study investigates effective connectivity in eye gaze processing networks in schizophrenia.

Purpose of the Study:

• To identify aberrant effective connectivity within brain networks involved in eye gaze processing in schizophrenia using dynamic causal modeling (DCM).
• To explore the neural underpinnings of gaze processing deficits in schizophrenia.
• To assess the relationship between altered connectivity and social cognition/functioning.

Main Methods:

• Utilized functional magnetic resonance imaging (fMRI) during an eye gaze processing task in 27 schizophrenia patients (SZ) and 22 healthy controls (HC).
• Employed dynamic causal modeling (DCM) to analyze effective connectivity between four key brain regions: secondary visual cortex, posterior superior temporal sulcus, inferior parietal lobule, and posterior medial frontal cortex.
• DCM analysis examined connectivity during explicit gaze discrimination and implicit gaze processing tasks.

Main Results:

• Schizophrenia patients exhibited altered connectivity, including reduced bottom-up and enhanced top-down connections during general gaze processing.
• Explicit gaze discrimination in SZ was associated with increased frontal inhibition of the visual cortex.
• Altered effective connectivity significantly correlated with poorer social cognition and functioning in patients.

Conclusions:

• General eye gaze processing in schizophrenia involves distributed cortical dysfunction and altered bidirectional connectivity.
• Explicit gaze discrimination is characterized by top-down abnormalities within the visual system.
• Identified neural mechanisms may serve as potential biomarkers for schizophrenia interventions.