Association of fronto-temporal function with cognitive ability in schizophrenia

Shenghong Pu,Masashi Itakura,Kazuyuki Nakagome,Masaaki Iwata,Izumi Nagata,Koichi Kaneko

doi:10.1038/srep42858

Abstract

Deficits in neuropsychological performance are common in schizophrenia, but their relationship with the fronto-temporal functional abnormalities associated with this condition remains unclear. We explored the relationship between neuropsychological performance as measured using the Brief Assessment of Cognition in Schizophrenia (BACS) and the Social Cognition Screening Questionnaire theory of mind (ToM) subscale and fronto-temporal function in 23 patients with schizophrenia and 23 age- and gender-matched healthy controls (HCs), using 52-channel near-infrared spectroscopy (NIRS). Regional hemodynamic changes were significantly smaller in the schizophrenia group than in the HCs group in the ventro-lateral prefrontal cortex and the anterior part of the temporal cortex (VLPFC/aTC) and dorso-lateral prefrontal cortex and frontopolar cortex (DLPFC/FPC) regions. To dissect the effect of variance in BACS cognitive domains from the relationship between ToM function and fronto-temporal function, we performed additional partial correlation analyses between ToM and NIRS data, using BACS composite score as a control variable. The correlation between ToM and NIRS data remained significant only in the DLPFC/FPC region. This finding is important to models of recovery, as it suggests that intervention programs focusing on enhancing fronto-temporal function may have a greater impact on social and occupational outcomes than traditional rehabilitation programs focusing on neuropsychological performance.

Highlights

Cognitive impairments are recognized as core functional deficits of schizophrenia and are a major factor in the unsuccessful re-entry of patients with schizophrenia into the community after treatment[1,2]
The response sensitivity A′and reaction time (RT) scores in the 2-back task during near-infrared spectroscopy (NIRS) measurement were significantly worse in the schizophrenia group than in healthy controls (HCs) (Table 1)
We used multi-channel NIRS to identify a relationship between working memory-related hemodynamic responses in fronto-temporal regions and neuropsychological performance as measured using the Brief Assessment of Cognition in Schizophrenia (BACS) and the theory of mind (ToM) in patients with schizophrenia

Summary

Introduction

Cognitive impairments are recognized as core functional deficits of schizophrenia and are a major factor in the unsuccessful re-entry of patients with schizophrenia into the community after treatment[1,2]. Schizophrenia is associated with deficits in multiple cognitive domains, including the neurocognitive domains (selective and sustained attention, working memory, episodic memory, processing speed, executive function) and the social cognitive domains[2]. Social cognitive ability has garnered attention in schizophrenia research because of its relationship to functioning[15] and its potential as a proximal target for treatment aimed at improving social functioning[16]. Existing research indicates that: 1) both neurocognitive and social cognitive abilities are impaired in schizophrenia and predict the level of functioning18,19; 2) social cognitive impairments appear to be present in schizophrenia across different phases of the illness[20,21]; and 3) neurocognitive and social cognitive domains correlate in the medium-range[22,23]. Having found that good social cognitive ability is extremely rare in the presence of poor neurocognitive ability, and that the reverse is far more common, we may speculate that neurocognitive ability form a “necessary” basis of social cognitive ability[17]

Methods

Results

Conclusion