高自閉症特質與有意識及無意識人臉訊息歷程之神經機制

Abstract

異常的人臉訊息處理歷程是自閉症類群障礙（Autism Spectrum Disorder, ASD）的特徵之一。即使過去的相關研究已經廣泛地檢驗自閉症類群障礙在處理有意識人臉訊息的神經機制，目前的研究對於自閉症個案如何處理無意識人臉訊息的了解仍然不足。此研究透過功能性磁振造影實驗、執行不連續閃現抑制作業（discontinuous flashing suppression task, dCFS task），並採用單變量分析及關注區域（ROI）分析，來檢驗具有不同程度自閉症特質的一般發展（typical development, TD）成年族群在處理有意識及無意識人臉訊息的神經運作模式。研究結果顯示，高自閉症特質的受試者與低自閉症特質的受試者相比，在處理有意識人臉訊息時具有異常的神經機制，包括招募較多與視覺訊息處理相關的神經活動反應，以及招募較少與人臉訊息處理相關的神經活動反應。另外，高自閉症特質的受試者在區辨無意識人臉訊息與無意識非人臉訊息的能力較差。除此之外，本研究發現中央旁小葉（paracentral lobule, PCL）的活化反應 – 與自閉症相關的潛在神經標記 – 在高自閉症特質受試者處理無意識人臉訊息時顯著下降。未來研究需要採用其他分析方法來進一步了解高自閉症特質族群在處理有意識及無意識人臉訊息背後的神經機制。

Atypical face processing is a distinctive feature of autism spectrum disorder (ASD). While previous research has extensively studied the mechanisms of conscious face processing in autism, a notable gap in understanding how individuals with autism process unconscious face information still exists. This study investigates the neural patterns associated with both conscious and unconscious face processing among typically developed populations with varying levels of autistic traits by using fMRI experiments involving the discontinuous flashing suppression (dCFS) task. Univariate analyses and ROI analysis were applied to this study. Results show that participants with higher autistic traits recruited alternated neural patterns during conscious face processing, characterized by reduced activity in face-related regions and increased activity in regions related to visual processing. Moreover, these participants show difficulty in differentiating between unconscious face information and unconscious non-face information compared to those with lower autistic traits. Furthermore, decreased activity in the paracentral lobule (PCL), a potential marker for autism, is associated with atypical unconscious face processing among participants with higher autistic traits. Additional analytical approaches are warranted to further elucidate the mechanisms underlying atypical conscious and unconscious face processing in relation to higher autistic traits.