Modeling Self-Reference in Schizophrenia: The Role of Evidence Accumulation in Social Perception and Paranoia

Individuals with schizophrenia (SZ) show difficulties determining whether environmental cues, particularly in social contexts, are meant for them, which relates to symptoms and determinants of social functioning. Recent computational modeling findings have emphasized disruptions in evidence accumulation, which index how visual information is extracted from social cues, as a potential driver. Yet, it is unclear whether these disruptions reflect more general difficulties with social/face processing or are specific to self-referential gaze perception, and how they map onto clinical features. We used drift diffusion modeling (DDM) to clarify cognitive processes driving self-referential gaze perception and non-self-referential gender perception in 39 SZ and 42 controls. DDMs captured key cognitive processes, including sensitivity of evidence accumulation to gaze and gender cues, perceptual biases, and expectation biases. We clarified whether disruptions to these processes in SZ were unique to self-referential judgments or general to face processing, and to what extent they related to paranoia and social cognition. Relative to controls, SZ exhibited perceptual biases specific to self-referential decisions, predisposing the over perception of eye contact, and broad reductions in evidence accumulation sensitivity to social cues during both self-referential and non-self-referential decisions. Broad insensitivities to gaze and gender cues, not perceptual biases, were associated with more severe paranoia in SZ. This suggests that aberrant self-reference in SZ is shaped by disruptions in the process of accumulating evidence during general social and self-referential information processing. More general disruptions in evidence accumulation, across different kinds of social decisions, may help bridge perceptual dysfunctions and symptoms, such as paranoia, in SZ.