School of Foreign Languages, Hunan University, Changsha, China.
Research Centre for Language, Cognition, and Neuroscience & Department of Chinese and Bilingual Studies, The Hong Kong Polytechnic University, Hong Kong SAR, China.
Autism Res. 2021 Jul;14(7):1357-1374. doi: 10.1002/aur.2509. Epub 2021 Mar 31.
The presence of vowel exaggeration in infant-directed speech (IDS) may adapt to the age-appropriate demands in speech and language acquisition. Previous studies have provided behavioral evidence of atypical auditory processing towards IDS in children with autism spectrum disorders (ASD), while the underlying neurophysiological mechanisms remain unknown. This event-related potential (ERP) study investigated the neural coding of formant-exaggerated speech and nonspeech in 24 4- to 11-year-old children with ASD and 24 typically-developing (TD) peers. The EEG data were recorded using an alternating block design, in which each stimulus type (exaggerated/non-exaggerated sound) was presented with equal probability. ERP waveform analysis revealed an enhanced P1 for vowel formant exaggeration in the TD group but not in the ASD group. This speech-specific atypical processing in ASD was not found for the nonspeech stimuli which showed similar P1 enhancement in both ASD and TD groups. Moreover, the time-frequency analysis indicated that children with ASD showed differences in neural synchronization in the delta-theta bands for processing acoustic formant changes embedded in nonspeech. Collectively, the results add substantiating neurophysiological evidence (i.e., a lack of neural enhancement effect of vowel exaggeration) for atypical auditory processing of IDS in children with ASD, which may exert a negative effect on phonetic encoding and language learning. LAY SUMMARY: Atypical responses to motherese might act as a potential early marker of risk for children with ASD. This study investigated the neural responses to such socially relevant stimuli in the ASD brain, and the results suggested a lack of neural enhancement responding to the motherese even in individuals without intellectual disability.
婴儿指向言语（IDS）中元音夸张的存在可能适应言语和语言习得的年龄适当需求。以前的研究为自闭症谱系障碍（ASD）儿童对 IDS 的异常听觉处理提供了行为证据，而潜在的神经生理机制尚不清楚。这项事件相关电位（ERP）研究调查了 24 名 4 至 11 岁 ASD 儿童和 24 名正常发育（TD）同伴对具有夸张和非夸张语音的语音和非语音的神经编码。EEG 数据使用交替块设计进行记录，其中每种刺激类型（夸张/非夸张声音）以相等的概率呈现。ERP 波形分析显示 TD 组中元音共振峰夸张的 P1 增强，但 ASD 组中没有。ASD 中未发现这种针对语音的异常处理，对于非语音刺激，ASD 和 TD 组均显示出相似的 P1 增强。此外，时频分析表明，ASD 儿童在处理非语音中嵌入的声音共振峰变化时，在 delta-theta 频段的神经同步存在差异。总的来说，这些结果为 ASD 儿童对 IDS 的异常听觉处理提供了神经生理学证据（即元音夸张的神经增强效应缺失），这可能对语音编码和语言学习产生负面影响。
摘要：对婴儿语的异常反应可能是 ASD 儿童风险的潜在早期标志物。本研究调查了 ASD 大脑对这种与社会相关的刺激的神经反应，结果表明，即使在没有智力障碍的个体中，对婴儿语也缺乏神经增强反应。
