Aberrant neural networks for the recognition memory of socially relevant information in patients with schizophrenia

한글 요약

조현병 환자의 기억 장애, 특히 사회적으로 의미 있는 정보를 재인하는 능력의 저하가 어떤 뇌연결망 이상과 관련되는지 살핀 연구입니다. 환자와 대조군이 사회적 상황 그림에 맞는 주제어를 고르는 과제를 수행한 뒤, fMRI 안에서 제시된 단어가 이전에 본 것인지 새로운 것인지 판별하는 재인 과제를 수행했으며, 독립성분분석(ICA)으로 기능적 연결망을 비교했습니다. 환자는 재인 변별력이 낮았고 정답 반응 시 우측 상측두이랑의 활동이 증가했으며, 전두극 연결망과 언어 이해 연결망에서 비정상적인 연결망 활동이 관찰되었습니다. 이러한 연결망 이상이 환자의 낮은 재인 수행과 사회적 기능 저하에 기여할 가능성이 있으며, 두 연결망이 치료 표적이 될 수 있음을 시사합니다.

INTRODUCTION: Patients with schizophrenia exhibit several cognitive deficits, including memory impairment. Problems with recognition memory can hinder socially adaptive behavior. Previous investigations have suggested that altered activation of the frontotemporal area plays an important role in recognition memory impairment. However, the cerebral networks related to these deficits are not known. The aim of this study was to elucidate the brain networks required for recognizing socially relevant information in patients with schizophrenia performing an old-new recognition task.

METHODS: Sixteen patients with schizophrenia and 16 controls participated in this study. First, the subjects performed the theme-identification task during functional magnetic resonance imaging. In this task, pictures depicting social situations were presented with three words, and the subjects were asked to select the best theme word for each picture. The subjects then performed an old-new recognition task in which they were asked to discriminate whether the presented words were old or new. Task performance and neural responses in the old-new recognition task were compared between the subject groups. An independent component analysis of the functional connectivity was performed.

RESULTS: The patients with schizophrenia exhibited decreased discriminability and increased activation of the right superior temporal gyrus compared with the controls during correct responses. Furthermore, aberrant network activities were found in the frontopolar and language comprehension networks in the patients.

CONCLUSIONS: The functional connectivity analysis showed aberrant connectivity in the frontopolar and language comprehension networks in the patients with schizophrenia, and these aberrations possibly contribute to their low recognition performance and social dysfunction. These results suggest that the frontopolar and language comprehension networks are potential therapeutic targets in patients with schizophrenia.