6-12岁自闭症谱系障碍儿童音调感知的认知神经机制：横向与纵向追踪研究

Despite having impairments in language and social communication, children with autism spectrum disorder (ASD) demonstrate pitch perception superiority in the auditory domain. The enhanced pitch-processing phenomenon has drawn researchers’ attention to the issue of atypical perception in autism. The study of this issue would not only contribute to the discovery of the potential biomarkers for early diagnosis of autism, but also can help to understand other extraordinary cognitive abilities of ASD and the mechanism of their impaired oral communication skills. However, previous work has exclusively relied on the data from native speakers of non-tonal languages such as English, and it remains unclear whether the autistic enhancement in pitch perception operates universally regardless of participants’ language background. Indeed, pitch changes play a special role in tonal languages as they form phonemic contrasts at the syllabic level that signal differences in word meaning. In order to fill this knowledge gap, the current interdisciplinary project covering psychology, cognitive neuroscience and linguistics aims to address whether the heightened auditory discrimination or neural sensitivity to pitch differences in autism can be observed in lexical tone processing in speakers of Chinese, a tonal language. Moreover, we will infer whether the ASD’s development of language-specific neural representations for categorical pitch patterns in Chinese is impaired. Further, in a following three-year longitudinal tracking study, we will track 20 six- to eight-year-old ASD children for three years to explore how the early development of ASD’s pitch perception ability would relate to their later development of the ASD symptoms, and whether such early development could predict their performance after they receive the traditional ASD rehabilitation training.

作为一种发育障碍，自闭症谱系障碍个体既表现出某些认知功能的缺陷，又具备“岛状”智力特征。在语音感知领域，研究发现，相比于正常人，自闭症个体在音调知觉方面具有普遍而稳定的优势，对该现象的深入研究，不仅有利于自闭症诊断标准的科学制定，还有助于揭示自闭症个体其他知觉优势现象，及其口语交流障碍的成因。本项目采用心理学、认知神经科学、语言学等多学科交叉的思路，以汉语语音中“声调携带语义”的特点作为研究切入点，考察声调语言环境下成长的自闭症儿童如何进行音调信息的感知与范畴化，及其如何受语义维度信息的影响。在此基础上，揭示自闭症儿童在构建语言特异性语音表征方面可能存在的缺陷，以及这种缺陷如何对声调范畴化的发展产生影响。同时，本项目还采用纵向追踪设计，考察自闭症儿童早期音调感知的特点与其随后自闭症状的发展和干预措施有效性的关系，以探讨和揭示低水平感知障碍如何影响自闭症个体交流障碍症状的发展和改善。

社交障碍是自闭症个体最为典型的症状之一。语音加工在社会交流中起到了由表层语音信息向深层语义信息过渡的重要作用。以往研究发现，自闭症个体在语音知觉方面具存在异常，这可能是导致他们出现社会感知和社交障碍的重要原因之一。本项目结合心理学、认知神经科学、语言学等多学科交叉的思路，以汉语语音中“声调携带语义”的特点作为研究切入点，采用脑电技术考察了声调语言环境下成长的自闭症儿童的音调信息感知特征。围绕这一问题，我们考察了声调语言环境下成长的自闭症儿童如何进行音调信息的感知与范畴化，及其如何受语义维度信息的影响。结果发现，自闭症儿童在加工中文声调信息时表现出劣势，且在音节刺激连续体的分辨中的范畴化较差。基于自闭症儿童的中文声调感知劣势特征，我们进一步探讨了自闭症儿童声调感知缺陷如何与元音和辅音相整合，结果发现，在对声调和元音这两个相对同时出现的音素进行整合这一任务上，自闭症儿童存在着一定的困难，这也影响了他们对音节的感知加工。其次，我们探讨了自闭症儿童社会性信息感知的认知神经机制。结果发现，自闭症儿童对自己名字的声音信息也不敏感，表有自闭症儿童在利用语音通达自我信息方面，他们也存在困难。最后，基于自闭症儿童的语音加工特征，我们也探索了自闭症儿童的预测模型与言语训练的可行性。结果发现反映语音加工的脑电指标可预测不同亚型的自闭症儿童，且多说话人语音识别训练的方法可有效提高语音的感知能力。综上，本项目围绕自闭症个体的语音加工异常机制深入研究，从语音加工的角度尝试揭示社交障碍的底层机制，为自闭症儿童言语发展的干预与改善提供了科学建议。