Department of Neurological Surgery, University of California, San Francisco, CA, USA.
Center for Integrative Neuroscience, University of California, San Francisco, CA, USA.
Nat Commun. 2021 Feb 19;12(1):1161. doi: 10.1038/s41467-021-21430-x.
Languages can use a common repertoire of vocal sounds to signify distinct meanings. In tonal languages, such as Mandarin Chinese, pitch contours of syllables distinguish one word from another, whereas in non-tonal languages, such as English, pitch is used to convey intonation. The neural computations underlying language specialization in speech perception are unknown. Here, we use a cross-linguistic approach to address this. Native Mandarin- and English- speaking participants each listened to both Mandarin and English speech, while neural activity was directly recorded from the non-primary auditory cortex. Both groups show language-general coding of speaker-invariant pitch at the single electrode level. At the electrode population level, we find language-specific distribution of cortical tuning parameters in Mandarin speakers only, with enhanced sensitivity to Mandarin tone categories. Our results show that speech perception relies upon a shared cortical auditory feature processing mechanism, which may be tuned to the statistics of a given language.
语言可以使用共同的声音组合来表示不同的意思。在声调语言中，如汉语普通话，音节的音高轮廓可以区分不同的单词，而在非声调语言中，如英语，音高则用于表达语调。语音感知中语言专业化的神经计算尚不清楚。在这里，我们使用跨语言的方法来解决这个问题。母语为汉语普通话和英语的参与者分别听汉语普通话和英语的语音，同时直接从非主要听觉皮层记录神经活动。两组参与者在单个电极水平上都表现出对说话者不变音高的语言通用编码。在电极群体水平上，我们发现只有汉语普通话使用者的皮质调谐参数具有语言特异性分布，对汉语声调类别的敏感性增强。我们的结果表明，语音感知依赖于共享的皮质听觉特征处理机制，该机制可能根据特定语言的统计数据进行调整。
