Self-reported social functioning and prefrontal hemodynamic responses during a cognitive task in schizophrenia.

Impaired social functioning is a characteristic of schizophrenia that affects patients' quality of life. The aim of the study was to assess prefrontal hemodynamic responses during a cognitive task and establish its influence on psychiatric symptoms, cognitive function, global functioning, and self-reported social functioning in patients with schizophrenia. Thirty-three patients with schizophrenia and 30 age-and sex-matched healthy controls participated in the study. We measured hemodynamic responses in the prefrontal and superior temporal cortical surface areas with 52-channel near-infrared spectroscopy (NIRS) during a verbal fluency task (VFT). Self-reported social functioning was assessed using the Social Functioning Scale (SFS). Regional hemodynamic responses were significantly smaller in the prefrontal and temporal regions in subjects with schizophrenia than in the controls, and prefrontal hemodynamic responses during the VFT showed a strong correlation with SFS total scores. These results suggest an association between self-reported social functioning and prefrontal activation in subjects with schizophrenia. The present study provides evidence that NIRS imaging could be helpful in understanding the neural basis of social functioning.