Sensory Mechanisms of Voice Control

描述(申请人提供)：语音障碍是影响沟通障碍的最常见的障碍之一。患有这些障碍的人难以与他人沟通，这些障碍可能会对他们的职业生涯造成不利影响，人们往往会变得与社会隔绝。如果不对这些疾病的原因有扎实的了解，我们就不能采取任何措施来预防这些疾病。缺乏理解的部分原因是对声音的正常控制机制缺乏基本知识。据推测，感觉反馈可能参与了对声音的控制，但几乎没有确凿的证据支持这一说法。 本研究的总体目标是了解感觉反馈在语音基频(F0)和强度控制中的作用。人们使用他们的声音来进行各种功能，如演讲、唱歌和表达情感。为了充分了解声音F0和强度是如何控制的，我们必须在不同的任务中研究它们，因为从对其他运动系统的研究中可以知道，感觉反馈的重要性根据任务的要求而有所不同。当受试者从事不同的发声任务时，将研究来自喉部的听觉和运动反馈。该方案的总体假设是，音调和响度变化反射的大小取决于喉部运动反馈的存在，并根据感觉反馈对特定任务中F0的准确性和强度控制的重要性而不同。通过测试人们在不同任务中使用声音时的声音反射，我们将了解到感觉反馈是如何在任务中调节的。据推测，在需要熟练使用声音的任务中，听觉反射的幅度会增加，发声的频率和强度都会增加。被测试的任务包括音调匹配、音量调节、语音和唱歌音阶。它还假设，动觉和听觉反馈在它们对声音的控制中相互作用。这种相互作用在先导研究中表现出来，在这些研究中，当声带被麻醉或当振动刺激施加到喉部时，音调变化反射的幅度显著增加。改变声带的动觉反馈，同时测试听觉反射，将为控制这两个反馈来源之间相互作用的大脑机制提供重要信息。

DESCRIPTION (provided by applicant): Voice disorders are among the most prevalent disorders affecting people with communication disabilities. People afflicted with these disorders have difficulty communicating with others, the disorders may adversely affect their careers, and the people often become socially isolated. There is little we can do to prevent these disorders without a solid understanding of their cause. Part of the reason for this lack of understanding is because of the lack of basic knowledge of normal control mechanisms of the voice. It is assumed that sensory feedback may be involved in control of the voice, but there is little hard evidence to support this claim. The overall goal of this research project is to understand the function of sensory feedback in the control of voice fundamental frequency (F0) and intensity. People use their voice for a variety of functions such as speech, singing and emotional expression. To fully understand how voice F0 and intensity are controlled, we must study them in different tasks, because it is known from research in other motor systems that the importance of sensory feedback varies according to the demands of the task. Auditory and kinesthetic feedback from the larynx will be studied as subjects are engaged in different vocal tasks. The overall hypothesis of the proposal is that the magnitude of pitch and loudness shift reflexes depend on the presence of laryngeal kinesthetic feedback and vary according to the importance of sensory feedback for accuracy of F0 and intensity control in specific tasks. By testing vocal reflexes as people are using their voice in different tasks, we will learn how sensory feedback is modulated in the tasks. It is hypothesized that auditory reflex magnitudes will increase in tasks that require skilled use of the voice, both in frequency and intensity of phonation. The tasks to be tested include pitch matching, loudness regulation, speech and singing a musical scale. It is also hypothesized that kinesthetic and auditory feedback interact in their control of the voice. This interaction was shown in pilot studies in which the pitch-shift reflex dramatically increased in magnitude when the vocal folds were anesthetized or when vibratory stimuli were applied to the larynx. Altering kinesthetic feedback from the vocal folds and simultaneously testing auditory reflexes will provide important information on brain mechanisms that govern interaction between these two sources of feedback.