自他識別の発達とその障害  [in Japanese] Typical and atypical development of self-other discrimination  [in Japanese]

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Author(s)

    • 北 洋輔 Kita Yosuke
    • 国立精神・神経医療研究センター精神保健研究所 知的障害研究部 Department of Developmental Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry (NCNP)

Abstract

<p>【要旨】自他識別は、相互コミュニケーションや感情理解などの高次の社会性が発達する上で重要な基礎である。これまで社会性の障害と称される自閉症スペクトラム症(Autism Spectrum Disorders:ASD)の病態解明の手がかりとして自他識別に着目してきており、その研究の一端を紹介する。顔刺激を用いた自他識別の検討では、ASD児において右側下前頭回の機能低下が示された。また、社会性の障害が重いほど同領域の活動が低下しており、自他識別の認知プロセスの特異性が、社会性の障害に関連する可能性が示唆された。更に、この特異性の背景の一つとして、他者に対する自発的注意や初期選好を検討したところ、ASDでは社会的刺激に対する選好が乏しいことが示された。これらから、ASD児は他者に対する初期選好の乏しさから、自他識別の経験の喪失につながり、自他識別の未成熟や特異性といった非定型な発達過程を辿っているものと仮説立てられた。今後はASDの社会脳の特異性を発達の観点から更に検討し、治療などの実践的応用につなげることが求められるであろう。</p>

<p>Self-other discrimination is a basic cognitive ability for social development. Here, I introduce part of our research findings focusing on brain functions and behavioral characteristics for self-other discrimination in children with autism spectrum disorder (ASD). First, our near-infrared spectroscopy studies have shown that, during recognition of the self-face, healthy subjects showed increased activity of the right inferior frontal gyrus (IFG) compared to the left side, while ASD children did not show this lateral dominance. Moreover, these activities in the right IFG reflected ASD severity, such that more serious ASD characteristics corresponded with lower activity levels. These findings suggest that dysfunction in the right IFG responsible for self-other discrimination is one of the crucial neural substrates underlying ASD characteristics. Second, we performed behavioral studies to investigate preferences to social stimuli that can affect the development of self-other discrimination. We used motion-tracking systems to analyze child behaviors and have found that ASD children showed lower preferences for other people than normally developing children. Based on these research findings, we hypothesized a negative spiral model for atypical development of the social brain:1) ASD children show low preference for social stimuli;2) the lower preference leads to lack of experience in ASD children performing self-other discrimination;3) ASD children might show cognitive immaturity for self-other discrimination;4) ASD children experience more and more difficulty in self-other discrimination, and lose interest in social stimuli;and 5) this loss of interest and major difficulties cause lower preferences for social stimuli. We speculate that ASD children might experience atypical development of the social brain along this spiral.</p>

Journal

  • Japanese Journal of Cognitive Neuroscience

    Japanese Journal of Cognitive Neuroscience 18(3+4), 115-120, 2016

    Japanese Society of Cognitive Neuroscience

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