泛自閉症障礙的核心症狀乃是社交及溝通上的廣泛性異常(American Psychiatric Association, 2000) 。生活中，自閉症者普遍對情緒感知及區辨表現不良。然而行為研究上他們的情緒障礙表現卻呈現不一致的結果。而我們對於這個困難背後的神經機制仍然所知有限。 這個研究使用失匹配負波(Mismatch negativity, MMN)為方法，測試自閉症者在不投注注意力的狀況下，他們處理情緒人聲及聲音音頻的神經機制是否與其他人相同。實驗招收了二十三名自閉症者 (平均年齡 18.42歲，三名女性)，以及二十三名控制組 (平均年齡 18.84歲，三名女性)受試者。 實驗結果顯示，在不投注注意力狀況下，自閉症者在對憤怒音聲產生較小的MMN，此組間差在右大腦最為明顯。自閉症者對快樂音聲產生的MMN則與控制組沒有明顯差異。在對音頻改變偵測上，自閉症者不管對源自憤怒或快樂的單頻刺激。在任何一個電極分佈上都表現出較控制組弱的MMN。 本研究裡，自閉症者在處理情緒音聲刺激上，展現出對負向情緒（憤怒）區辨缺損。此缺損在右大腦最為明顯，可視為此研究對自閉症“右腦障礙“假說的ㄧ項支持。對正向情緒與控制組有相同的區辨程度：可能可用自閉症 “杏仁核缺損” 假說解釋，但需要進一步研究支持。此外自閉症者對音頻改變偵測的缺損由於不管在正負向情緒，頭表各部位電極都觀察到。與情緒音聲（刺激種類及電極分佈）選擇性缺損不同。故較傾向對音頻改變的缺損不是造成情緒區辨缺損的唯一因子。 Background: Dysfunction of emotion recognition is the core deficit of social impairment in individuals with Autism spectrum disorders (ASD) (American Psychiatric Association, 2000). Previous behavioral studies in emotion perception elicited inconsistent results. Besides, the neural mechanism for this dysfunction remains poorly understood. Methods& Results: By comparing the differences of mismatch negativity (MMN) responses between 23 participants with ASD and 23 TDC to emotional voices and the corresponding pure tones, we investigated the emotion perception and basic acoustic analysis in ASD at a pre-attentive level and the autistic trait by AQ. In emotional condition, MMN amplitude to angry voice is lower in individuals with ASD, specifically over the right hemisphere. Interestingly, no group difference was observed for happy voice. As for pitch changes, MMN amplitude was evenly smaller for both emotion over all electrodes. Conclusion: In the present study, individuals with ASD show impaired automatic emotion discrimination to angry voices, especially over the right hemisphere Absence of inter-group difference in MMN for happy voices may be explained by the amygdala theory, causing specific aversive emotion perception defiicit in ASD. Further study is needed to clarify this possibility. Smaller MMN for both emotion-derived pure tone over all electrodes makes it unlikely that the only deficit in tonal discrimination is sufficient to cause deficit in processing emotional vocal expression.
