Temporal Coordination in the Motor Speech System

描述（由申请人提供）：本研究申请旨在探讨正常衰老和损伤引起的神经运动限制如何导致语言中功能单元的不同动态组织。研究检查了在正常和机械干扰的说话条件下，多个发音器（嘴唇、下巴和声音）如何协调以实现感知上准确的说话。患有言语失用症（AOS）的言语运动编程障碍的个体将被考虑。AOS破坏了关节间的协调。研究表明，根据语言系统的神经运动和机械约束，特定的肌肉群或发音器作为功能单位是动态组织的。因此，据预测，这些单元的组织将随着说话者的神经运动能力和说话任务的要求而变化。假设正常衰老过程中产生的神经运动约束与AOS产生的神经运动约束不同，预测AOS说话者在机械扰动下的运动组织模式与年轻和老年典型说话者不同。这些组织上的差异将通过检查声音偏移的时间和开始以及在典型和受干扰的条件下嘴唇和下巴在生产/papa/时的运动学特性（嘴唇闭合的相对位移和持续时间，嘴唇闭合和张开的峰值速度和加速度）来测试。在健康的说话者中，将测试两种说话速度，以确定说话速度是否可以解释正常衰老或损伤的任何影响。扰动将包括一个意想不到的50g载荷向下施加在下唇上，或者早（在嘴唇闭合开始前约70毫秒）或晚（在嘴唇闭合开始后约20毫秒）。研究表明，对早期扰动的反应反映了运动编程过程，而对晚期扰动的反应反映了运动执行过程。AOS是一个理想的系统，因为它只破坏前者。DIVA神经网络模型用于开发特定的预测，结果将在此和其他当前运动控制模型的背景下进行解释。

DESCRIPTION (provided by applicant): This research application aims to investigate how neuromotor constraints arising from normal aging and from impairment result in different dynamic organization of functional units during speech. Studies examine how multiple articulators (lips, jaw, and voice) are coordinated to achieve perceptually accurate speech under normal and mechanically perturbed speaking conditions. Individuals with the speech motor programming disorder of Apraxia of Speech (AOS) will be considered. AOS disrupts inter-articulator coordination. Research has suggested that specific muscle groups or articulators are dynamically organized, as functional units, according to neuromotor and mechanical constraints of the speech system. As a result, it is predicted that the organization of these units will vary as a function of the neuromotor abilities of the speaker and the demands of the speaking task. Under the assumption that the neuromotor constraints arising from the normal aging process and those of AOS are different, it is predicted that different patterns of motor organization will be found in speakers with AOS versus young and older typical speakers in response to mechanical perturbation. These differences in organization will be tested by examining timing of voice offset and onset and kinematic properties (relative displacement and duration for lip closure, peak velocity and acceleration of lip closing and opening) of the lips and jaw in the production of/papa/under typical and perturbed conditions. In healthy speakers, two speaking rates will be tested to determine whether speech rate can explain any effects of normal aging or impairment. Perturbation will consist of an unexpected 50 g load applied downward on the lower lip either early (approximately 70 msec prior to onset of lip closure) or late (approximately 20 msec after onset of closure). It has been suggested that response to early perturbations reflects motor programming processes while response to late perturbations reflects movement execution processes. AOS is an ideal system as it only disrupts the former. The DIVA neural network model is used to develop specific predictions and results will be interpreted in the context of this and other current models of motor control.