Functional brain networks underlying evidence integration and delusional ideation

Area of Science:

• Neuroscience
• Cognitive Psychology
• Psychiatry

Background:

• Cognitive biases in evidence integration are implicated in delusions and psychosis.
• Previous work linked visual attention network (VsAN) hyperactivity and cognitive evaluation network (CEN) hypoactivity to delusions in schizophrenia.
• Aberrant functional connectivity in these networks may contribute to delusion maintenance.

Purpose of the Study:

• To investigate associations between cognitive biases, schizotypal traits, and brain activity during evidence integration in healthy individuals.
• To determine if aberrant functional connectivity patterns observed in clinical populations are present in non-clinical delusional ideation.
• To explore the neural underpinnings of delusional ideation in the psychosis continuum.

Main Methods:

• fMRI-CPCA (Constrained Principal Component Analysis for fMRI) was used to analyze functional brain activity during evidence integration.
• 41 healthy individuals completed behavioral assessments of cognitive biases and schizotypal traits.
• Functional connectivity was examined in relation to default-mode network (DMN), CEN, and VsAN activity.

Main Results:

• Schizotypal traits were positively associated with cognitive biases, specifically driven by delusional ideation.
• Delusional ideation correlated with decreased CEN activity during disconfirmatory evidence processing.
• Delusional ideation was also associated with increased VsAN activity during confirmatory evidence processing.

Conclusions:

• Altered patterns of brain network activation during evidence integration, specifically involving the CEN and VsAN, are associated with delusional ideation in healthy individuals.
• These findings suggest that the neural mechanisms underlying evidence integration deficits may represent a transdiagnostic vulnerability across the psychosis continuum.
• The study highlights the role of aberrant network activity in the development and maintenance of delusional ideation, even in the absence of clinical delusions.