Top-Down Inhibitory Mechanisms Underlying Auditory-Motor Integration for Voice Control: Evidence by TMS
Top-Down Inhibitory Mechanisms Underlying Auditory-Motor Integration for Voice Control: Evidence by TMS
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DOI：
10.1093/cercor/bhaa054
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发表时间：
2020-08-01
期刊：
影响因子：
3.7
通讯作者：
Liu, Hanjun
中科院分区：
文献类型：
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作者：
Liu, Dongxu;Dai, Guangyan;Liu, Hanjun
背外侧前额叶皮层（DLPFC）参与了精确控制发声的神经-运动整合，但其在这个基于反馈的过程中的确切作用在很大程度上仍然未知。为此，目前的事件相关电位研究应用经颅磁刺激（TMS）协议，连续theta-突发刺激（c-TBS），以破坏左侧DLPFC的皮质活动，因为年轻人发出元音，同时听到他们的声音意外地向上移动音高。结果表明，与假手术条件相比，c-TBS在左DLPFC导致了显着更大的语音补偿音高扰动，伴随着显着更小的皮层P2反应。源定位分析表明，这种脑活动模式是左额上级回和右顶下小叶（缘上回）激活减少的结果。这些研究结果表明，c-TBS诱导的DLPFC对音高调节的神经行为处理的调制作用，这表明，干扰前额叶功能可能会损害自上而下的抑制控制机制，防止语音生产过度受到听觉反馈的影响，从而增强反馈扰动的声音补偿。这是第一个研究，提供了直接的证据，因果关系的作用，左DLPFC的听觉反馈控制发声。
The dorsolateral prefrontal cortex (DLPFC) has been implicated in auditory-motor integration for accurate control of vocal production, but its precise role in this feedback-based process remains largely unknown. To this end, the present event-related potential study applied a transcranial magnetic stimulation (TMS) protocol, continuous theta-burst stimulation (c-TBS), to disrupt cortical activity in the left DLPFC as young adults vocalized vowel sounds while hearing their voice unexpectedly shifted upwards in pitch. The results showed that, as compared to the sham condition, c-TBS over left DLPFC led to significantly larger vocal compensations for pitch perturbations that were accompanied by significantly smaller cortical P2 responses. Source localization analyses revealed that this brain activity pattern was the result of reduced activation in the left superior frontal gyrus and right inferior parietal lobule (supramarginal gyrus). These findings demonstrate c-TBS-induced modulatory effects of DLPFC on the neurobehavioral processing of vocal pitch regulation, suggesting that disrupting prefrontal function may impair top-down inhibitory control mechanisms that prevent speech production from being excessively influenced by auditory feedback, resulting in enhanced vocal compensations for feedback perturbations. This is the first study that provides direct evidence for a causal role of the left DLPFC in auditory feedback control of vocal production.