Functional organization of human sensorimotor cortex for speech articulation

摘要

说话的动作需要嘴唇、下巴、舌头和喉部的活rn动在时间上精确协调。Edward Chang及其同rn事对这种精确运动控制的神经基础进行了研rn究。人感觉运动皮层中的多电极记录显示，语rn言中所涉及的大脑区域是根据面部和声带的一rn种“躯体特定区”表示方式布局的，其中大量rn细胞相应于特定语音特征。研究人员特别感兴rn趣的是位于“腹侧感觉运动皮层”“最背端”rn(dorsal-most end)的另一个喉部表示(在非人rn类灵长目动物中显然是没有的)，它可能是专rn为控制语言而形成的一个特征。%Speaking is one of the most complex actions that we perform, but nearly all of us learn to do it effortlessly. Production of fluent speech requires the precise, coordinated movement of multiple articulators (for example, the lips, jaw, tongue and larynx) over rapid time scales. Here we used high-resolution, multi-electrode cortical recordings during the production of consonant-vowel syllables to determine the organization of speech sensorimotor cortex in humans. We found speech articulator representations that are arranged somatotopically on ventral pre- and post-central gyri, and that partially overlap at individual electrodes. These representations were coordinated temporally as sequences during syllable production. Spatial patterns of cortical activity showed an emergent, population-level representation, which was organized by phonetic features. Over tens of milliseconds, the spatial patterns transitioned between distinct representations for different consonants and vowels. These results reveal the dynamic organization of speech sensorimotor cortex during the generation of multi-articulator movements that underlies our ability to speak.