Cortical Mechanisms of Auditory-Vocal Interaction

描述(申请人提供)：这项研究的总体目标是了解我们在说话时如何倾听自己的声音，以及我们如何利用这些信息来帮助控制我们的言语。人类拥有复杂的机制，可以在语音过程中自我监控这种声音反馈，从而检测和补偿发声错误。这种自我监控的退化，如听力损失，会导致获得和维持正常语音的困难，并损害语音交流。最近在人类和灵长类动物中的研究表明，发声过程中听觉皮质的神经活动受到抑制，这可能在自我监控中发挥作用。这种神经活动的起源和意义尚不清楚。这项建议侧重于确定发声过程中自我监控的神经机制及其在反馈发声控制中的作用，使用的是人类受试者和发声灵长类动物模型--绒猴。目的1验证一种假说，即被抑制的猕猴听皮层神经元具有自我监控活动，这种神经活动可以驱动代偿性发声控制。听觉皮质神经元是从发出声音的绒猴身上记录下来的，同时改变它们发声反馈的频率内容以诱导发声补偿。神经记录之后是对听觉皮质的电刺激，以扰乱自我监测和由此产生的反馈补偿。这些实验将展示听觉皮质中发声自我监控活动如何驱动反馈发声控制。目的2验证前额叶皮质，特别是运动前皮质，是导致听觉皮质发声抑制的神经信号来源的假说。同时记录了绒猴额叶和听觉皮质中的神经元，并应用定量分析来证明发声过程中大脑区域之间的神经连接。这些结果将证明听觉皮质以外的神经通路对发声自我监控有贡献。目的3验证人类听觉皮质是语音自我监测和反馈发声控制所必需的假说。在接受NeuRA癫痫手术监测的患者中，使用脑皮质电活动来记录听觉皮质活动。与动物实验平行的是，在改变音调的语音反馈过程中，对大脑皮层的电刺激被执行，以展示听觉皮质在反馈补偿中的作用。这些实验将对理解语音运动控制有意义，并将允许在人类语音和动物发声之间进行机械性比较。当我们试图将动物神经生理学的结果转化为理解人类语言产生时，这样的比较是至关重要的。

DESCRIPTION (provided by applicant): The overall objective of this research is to understand how we listen to the sound of our own voice while talking and how we use this information to help control our speech. Humans have sophisticated mechanisms for self-monitoring of this vocal feedback during speech that allow for the detection and compensation for vocal errors. Degradation of this self-monitoring, such as following hearing loss, results in difficulty in acquiring and maintaining normal speech and impairs vocal communication. Recent work in both humans and primates has demonstrated a suppression of neural activity in the auditory cortex during vocalization that may play a role in self-monitoring. The origin and significance of this neural activity is unknown. This proposal focuses on determining the neural mechanism of self-monitoring during vocal production and its role in feedback vocal control, using both human subjects and a vocal primate model, the marmoset monkey. Aim 1 tests the hypothesis that suppressed neurons of the auditory cortex in marmosets exhibit self- monitoring activity, and that this neural activity can drive compensatory vocal control. Auditory cortex neurons are recorded from vocalizing marmosets while altering the frequency content of their vocal feedback to induce vocal compensation. Neural recording is followed by electrical stimulation of the auditory cortex in order to disrupt self-monitoring and resulting feedback compensation. These experiments will demonstrate how vocalization self-monitoring activity in the auditory cortex drives feedback vocal control. Aim 2 tests the hypothesis that frontal cortical areas, particularl pre-motor cortex, are the origin of the neural signals that cause vocal suppression in auditory cortex. Neurons in both frontal and auditory cortex of marmosets are recorded simultaneously and quantitative analyses applied to demonstrate neural connectivity between brain regions during vocal production. These results will demonstrate the neural pathways beyond auditory cortex that contribute to vocal self-monitoring. Aim 3 tests the hypothesis that human auditory cortex is necessary for self-monitoring and feedback vocal control of speech. Auditory cortex activity is recorded using intracranial electrocorticographic activity in patients undergoing neura monitoring for epilepsy surgery. Paralleling the animal experiments, electrical stimulation of cortex is performed during pitch-altered speech feedback to demonstrate the role of auditory cortex in feedback compensation. These experiments will have implications for understanding speech motor control and will allow mechanistic comparisons between human speech and animal vocalization. Such comparisons are critical as we attempt to translate results from animal neurophysiology towards understanding human speech production.