Association between social functioning and prefrontal cortex function during a verbal fluency task in schizophrenia: A near‐infrared spectroscopic study

• Published in: Psychiatry and clinical neurosciences Vol. 71; no. 11; pp. 769 - 779
• Main Authors: Itakura, Masashi, Pu, Shenghong, Ohdachi, Hiroaki, Matsumura, Hiroshi, Yokoyama, Katsutoshi, Nagata, Izumi, Iwata, Masaaki, Kaneko, Koichi
• Format: Journal Article
• Language: English
• Published: Melbourne John Wiley & Sons Australia, Ltd 01.11.2017; Wiley Subscription Services, Inc
• Subjects: Adult; Aged; Attention deficit hyperactivity disorder; Caregivers; Case-Control Studies; Cognition - physiology; Cognitive ability; Cortex (temporal); Female; Frontal Lobe - physiopathology; Hemodynamics - physiology; Humans; I.R. radiation; Infrared spectroscopy; Male; Mental disorders; Middle Aged; near‐infrared spectroscopy; Neuropsychological Tests; Prefrontal cortex; Prefrontal Cortex - physiopathology; Psychopathology; Schizophrenia; Schizophrenia - physiopathology; Schizophrenic Psychology; Social Adjustment; social functioning; Specific Level of Functioning Assessment; Spectroscopy, Near-Infrared; Verbal Behavior - physiology; Young Adult; social functioning; near-infrared spectroscopy; Specific Level of Functioning Assessment; schizophrenia; prefrontal cortex
• ISSN: 1323-1316; 1440-1819
• DOI: 10.1111/pcn.12548

Aim Impaired social functioning is a common characteristic of patients with schizophrenia. Social functioning requires the complex operation of various executive functions. Deficits in the prefrontal cortex (PFC) have been implicated in executive dysfunction. Here we aimed to clarify the relation between subjectively and objectively assessed social functioning, and their associations with PFC function in patients with schizophrenia. Methods Twenty‐three patients and 22 age‐ and sex‐matched healthy controls (HC) were assessed. In the schizophrenia group, self‐ and caregiver‐rated social functioning were measured using the Specific Level of Functioning Assessment (SLOF). The hemodynamic responses elicited by a verbal fluency task (VFT) in three regions of interest in the frontotemporal area were measured using multi‐channel near‐infrared spectroscopy (NIRS). We also investigated psychiatric symptoms, neurocognition, and cognitive insight to assess possible confounding factors. Results Significant positive correlations were found between self‐ and caregiver‐rated SLOF composite scores and three subdomain scores. Self‐ and caregiver‐rated SLOF composite scores were significantly associated with dorsolateral PFC and frontopolar cortex (DLPFC/FPC) activation during the VFT. Psychiatric symptoms, global functioning, neurocognition, and cognitive insight were not associated with NIRS signals. General psychopathology was associated with NIRS signals in the ventrolateral PFC and the anterior temporal cortex. DLPFC and FPC activity may be associated with social functioning in patients with schizophrenia. Conclusion Our results suggest that the two distinct assessments of social functioning were significantly correlated. Moreover, DLPFC and FPC function was strongly associated with social functioning and the ability to carry out daily life in patients with schizophrenia.