Obleser Jonas, Scott Sophie K, Eulitz Carsten
Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London, WC1N 3AR, UK.
Cereb Cortex. 2006 Aug;16(8):1069-76. doi: 10.1093/cercor/bhj047. Epub 2005 Oct 5.
The apparently effortless identification of speech is one of the human auditory cortex' finest and least understood functions. This is partly due to difficulties to tease apart effects of acoustic and phonetic attributes of speech sounds. Here we present evidence from magnetic source imaging that the auditory cortex represents speech sounds (such as [g] and [t]) in a topographically orderly fashion that is based on phonetic features. Moreover, this mapping is dependent on intelligibility. Only when consonants are identifiable as members of a native speech sound category is topographical spreading out in the auditory cortex observed. Feature separation in the cortex also varies with a listener's ability to tell these easy-to-confuse consonants from one another. This is the first demonstration that speech-specific maps of features can be identified in human auditory cortex, and it will further help us to delineate speech processing pathways based on models from functional neuroimaging and non-human primates.
人类能轻松识别语音,这是听觉皮层最出色却又最不为人所理解的功能之一。部分原因在于难以区分语音的声学和语音属性的影响。在此,我们展示了来自磁源成像的证据,即听觉皮层以基于语音特征的拓扑有序方式表征语音(如[g]和[t])。此外,这种映射依赖于可懂度。只有当辅音能够被识别为母语语音类别中的成员时,才会在听觉皮层中观察到拓扑分布。皮层中的特征分离也会因听者区分这些容易混淆的辅音的能力而异。这是首次证明在人类听觉皮层中可以识别出特定于语音的特征图谱,它将进一步帮助我们根据功能神经成像和非人类灵长类动物的模型来描绘语音处理路径。