探討自閉症兒童青少年語義處理與執行功能之關聯

The Relationship between Semantic Processing and Executive Function in Autistic Children and Children without Autism

林海笛(Hai-Ti Lin)

指導教授 ： 高淑芬

國立臺灣大學/醫學院/臨床醫學研究所/碩士(2022年)

https://doi.org/10.6342/NTU202203533

摘要

自閉症類群障礙症是常見的神經發展疾病之一，兩大核心症狀分別為社交溝通缺損及重複、侷限的行為和興趣。除了上述核心症狀，執行功能缺損亦為自閉症孩童常有的表現，且執行功能缺損理論可以同時解釋自閉症的社交及非社交症狀。語義處理與執行功能缺損對於自閉症患者的生活影響顯著，包括學習成就與社會功能。過往研究發現針對自閉症孩童之語言發展遲緩的介入治療，同時可以改善其執行功能；以執行功能為治療目標，也同步促進自閉症孩童之社交發展。雖然分別以語義處理和執行功能為主題的研究在自閉症族群已有一定的進展，不過探討兩者關聯的研究卻很鮮少。此研究希望透過分析語義處理之腦影像變化、與劍橋神經認知測驗與執行功能行為評定量表測量之執行功能，進一步了解自閉症之病生理機轉。
本研究包含54位自閉症類群障礙症男孩與56位典型發展男孩，兩組受試者的年齡、智力及慣用手分佈均相當。受試者接受完整的臨床評估、以劍橋神經認知測驗與父母版執行功能行為評定量表測量其執行功能，進行語義處理任務（受試者需判斷先後出現在螢幕上的中文字語義是否相近）時同步接受腦部功能性磁振造影掃描。本研究使用迴歸分析來探討語義處理之神經活化及執行功能之間的關聯。
研究結果顯示相較於典型發展兒童，自閉症孩童有顯著之執行功能缺損。語義處理之腦部影像則發現自閉症孩童於右側緣上回（supramarginal gyrus）的活化增加，而在傳統語言區之左側額下回（inferior frontal gyrus）及額中回（middle frontal gyrus）之活化下降。上述腦區之神經活化程度與執行功能表現具相關性。
研究結果指出典型發展兒童傾向使用較高階之神經網絡來處理語義相關訊息，而自閉症孩童則倚賴較初級之視覺補償機制來進行語義處理。前述神經活化之變化與執行功能之行為表現相關。上述結果促進我們對於自閉症兒童語義處理與執行功能交互作用的理解。

關鍵字

自閉症類群障礙症 ； 語義處理 ； 功能性磁振造影 ； 執行功能 ； 緣上回

並列摘要

Objective: The neural alteration during semantic judgments and executive functions has been extensively investigated separately in autism. However, no studies have examined these two domains simultaneously. Therefore, the integrated understanding of the relationship between semantic processing and executive function is very important in the autistic population because both domains have prominent impacts.
Methods: Functional magnetic resonance imaging (fMRI) was used to investigate 54 autistic boys and 56 age-, handedness-, and intelligence quotient-matched non-autistic boys from age 7 to 18. Participants had to determine if the visually presented pairs of Chinese characters were semantically related during fMRI scanning. The assessment of executive functions was based on three tasks from the Cambridge neuropsychological test automated battery (CANTAB) and behavior rating inventory of executive function (BRIEF) parent form. In addition, the correlation between neural activation during semantic processing and executive function was examined through regression analysis.
Results: ASD group had prominent executive dysfunction compared to the comparison group. The brain imaging results revealed pronounced activation in the right supramarginal gyrus and reduced activation in the left inferior and middle frontal gyrus in autistic boys than in non-autistic boys. Neural activation over the above brain regions was associated with some dimensions of executive function measured by CANTAB and BRIEF.
Conclusions: Our findings implicate that autistic boys might depend on lower-level visual compensation during semantic processing. On the contrary, non-autistic boys might involve more in higher-level semantic networks. Such neural correlates were also related to the behavioral performance of the executive functions. The findings might shed light on the interplay between the semantic system and executive function in autistic children.

並列關鍵字

Autism ； Semantic ； Functional MRI ； Executive function ； Supramarginal gyrus

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