Dysconnectivity in the frontoparietal attention network in schizophrenia

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Science

Background:

• Cognitive impairment is a hallmark of schizophrenia, affecting attentional processes.
• The frontoparietal network (FPN) is crucial for attention and is hypothesized to be dysfunctional in schizophrenia.

Purpose of the Study:

• To investigate attentional modulation of FPN effective connectivity in schizophrenia patients using magnetoencephalography (MEG).
• To explore the relationship between FPN connectivity alterations and cognitive deficits in schizophrenia.

Main Methods:

• Utilized magnetoencephalography (MEG) to record brain activity in 14 schizophrenia patients and 18 healthy volunteers (HVs).
• Employed dynamic causal modeling (DCM) to analyze effective connectivity within the FPN during an attention-demanding visual task.
• Assessed attention-dependent changes in both top-down and bottom-up connections.

Main Results:

• Healthy volunteers showed greater cortical responses to attended visual changes compared to schizophrenia patients.
• Schizophrenia patients' FPN connectivity was best explained by attention-dependent top-down and bottom-up changes, while HVs showed only bottom-up changes.
• A significant reduction in connectivity changes between the right intraparietal sulcus (IPS) and temporoparietal junction (TPJ) was observed in schizophrenia patients, predicting lower intelligence.

Conclusions:

• Functional dysconnections within the FPN, particularly in the right IPS-TPJ pathway, contribute to cognitive impairment in schizophrenia.
• Attentional modulation of connectivity differs between schizophrenia patients and healthy individuals.
• These findings support the role of FPN disruptions in the pathophysiology of schizophrenia-related cognitive deficits.