Explicit and implicit mentalization of patients with first-episode schizophrenia: a study of self-referential gaze perception with eye movement analysis using hidden Markov models.

Mentalizing impairment is one of the core features of schizophrenia, and bias judgement of others' gaze as self-directing is common to schizophrenia patients. In this case-control study, 30 patients with first-episode schizophrenia (FES) and 30 matched healthy controls were assigned gaze perception tasks with variable stimulus presentation times (300 ms and no time limit) to determine the presence of self-referential gaze perception (SRGP) bias. The eye movement pattern during the task were tracked and data were analysed using hidden Markov models (HMMs). The SRGP involves reporting of others' gaze intent and was used as a measurement of explicit mentalizing process. Eye movement measurement represents automated visual attention pattern and was considered as a measurement of implicit mentalizing process. The patients with FES had significantly more SRGP bias than the controls in the 300 ms condition but not in the no-time-limit condition. Social cognitive function was related to SRGP bias in the patient group. Two distinct eye movement patterns were identified: eye-focused and nose-focused. Significant group differences in eye movement patterns in the 300 ms condition were found with more controls had eye-focused pattern. Social anxiety symptoms were related to the nose-focused pattern, positive psychotic symptoms were related to the eye-focused pattern, and depressive symptoms were related to less consistent eye movement patterns. No significant relationship was found between SRGP bias and eye movement patterns. The dissociation between explicit and implicit mentalizing processes with different cognitive and symptom dimensions associated with the two processes suggests the presence of different mechanisms.

Self-referential gaze perception of patients with schizophrenia and its relationship with symptomatology and cognitive functions.

Self-referential gaze perception (SRGP)-the perception that others' gaze is towards oneself-is a core experience in patients with schizophrenia, and may be related to common delusional themes such as delusions of reference. Studies exploring SRGP bias in schizophrenia are limited and results have been inconsistent, particularly regarding its relationship with symptomatology and cognition. Seventy-five patients with schizophrenia-spectrum disorders (25 with high level of reference delusion, 25 with low reference delusion and 25 in clinical remission) and 25 matched healthy controls were compared in a gaze perception task to judge whether averted gaze with varied ambiguity was directed at them. All subjects were assessed with delusion and reference ideations and cognitive functions. Psychotic symptoms were assessed in patients. Gaze perception analysis adopted both behavioural and psychophysical approaches. Group differences and predictors of SRGP in ambiguous and unambiguous conditions were investigated. Both groups of symptomatic patients displayed higher ambiguous SRGP rate, and the group with high reference delusions showed more unambiguous SRGP bias. Cognitive functions were negatively associated with SRGP rate while positive and negative symptoms were positively associated. Cognitive function was the only significant predictor for ambiguous-SRGP rate. Patients with psychotic symptoms have hypermentalization of gaze perception as towards oneself, whereas patients with delusions of reference have more profound bias in gaze perception. General cognition is implicated in SRGP rate. Future studies could investigate interventions with targeted psychopathological profiles by improving non-social cognitive functions to test the hypothesis that cognitive functioning is related to SRGP bias and delusional beliefs.