汉语声调加工的神经基础:来自半球偏侧化证据的启示

The Neural Basis of Chinese Lexical Tone Processing: Insights from Evidence on Hemispheric Lateralization

汉语声调在汉字(如单音节字)加工中起重要作用。功能假设认为言语加工偏向于左半球,而音乐加工偏向于右半球。声学假设则认为声音时间信息加工偏向于左半球,而音高(由声音频率决定)信息的加工偏向于右半球。由于汉语声调同时具有与音高相关的声学特征和与语言相关的音韵特征,所以大脑对汉语声调不同特征的加工会表现出不同的半球偏侧化效应。本文从半球偏侧化的视角综述了来自神经心理学、神经影像学、电生理学和行为学关于汉语声调加工的证据。未来研究可以从汉语声调相比声母和韵母加工的差异、汉语声调在语境加工中的作用、发展性阅读障碍儿童和二语习得者加工汉语声调的神经基础、音乐经验对汉语声调加工的影响方面探讨汉语声调加工的神经基础。

Chinese lexical tone plays an important role in the processing of Chinese characters (i.e., mono-syllables). The functional hypothesis proposes that speech processing is lateralized to the left hemisphere and that musical processing is lateralized to the right hemisphere. Alternatively, the acoustic hypothesis points out that acoustic temporal processing is lateralized to the left hemis-phere and that pitch (depended on the frequency of sounds) processing is lateralized to the right hemisphere. Because Chinese lexical tones have both low-level acoustic features (related to pitch) and higher-order phonological features (related to linguistic knowledge), the processing of different features in the brain tends toward different hemispheric lateralization. A series of evidence from neuropsychological, functional neuroimaging, electrophysiological, and behavioral studies is reviewed from the perspective of the hemispheric lateralization. Future research on the understanding of the neural bases of Chinese lexical tone concerns with the differences between tones, consonants, and vowels in the processing of Chinese characters, the role of Chinese lexical tone in the processing of semantic contexts, the neural underpinnings of Chinese lexical tone processing in developmental dyslexia and second-language learners, as well as the effects of musical experience on Chinese lexical tone processing.