A multimodal approach to identify atypical face processing in first episode psychosis (early schizophrenia spectrum disorders)

Background While social interaction difficulties are common in schizophrenia, the neural underpinnings for its social symptomatology are under-explored. In this study, we aimed to isolate atypical neural systems associated with live social interaction in first episode psychosis (early schizophrenia spectrum disorder). Methods A two-person live face gaze paradigm was employed as the behavioral proxy for social interaction while electroencephalography (EEG), functional near infrared spectroscopy (fNIRS), eye tracking, and facial movement measures were simultaneously acquired. Findings were compared for 24 first episode psychosis (FEP) patients and 32 typically developed (TD) participants to test the hypothesis that these neural and behavioral measures would isolate atypical social neural systems in the FEP group. Results FNIRS neural data showed atypical hemodynamic activity in the right temporoparietal region, known to be associated with live face-to-face interactions. This atypical activity was significantly correlated with expressive deficit score, a sub score derived from PANSS negative symptom domain and N4, a PANSS negative symptom which measures passive/apathetic social withdrawal. Involuntary behavioral responses associated with spontaneous facial mimicry and gaze fixation were reduced in FEP. Consistent with previous findings, Event Related Potential (ERP) amplitudes and latencies were atypical in FEP during the first 100–300 ms in the right temporoparietal electrodes, along with reduced theta oscillation power. Conclusion Together, the identified regions represent atypical live face processing systems in early schizophrenia spectrum disorder, which is further correlated with expressive deficits and social withdrawal. The study emphasizes the need for ecologically valid multimodal data acquisition to detect neural hubs crucial in live face processing in early schizophrenia.