Motor Correlates of Song Production

描述（由申请人提供）：鸣禽和鹦鹉是为数不多的人类语言动物模型之一，在这些模型中，有可能实验研究产生复杂的、习得的发声所涉及的基本生理和声学问题。这些鸟类作为语言产生的外围机制模型的有用性受到限制，然而，尽管咽上声道在语言的发音中起着卓越的作用，但它是鸟类声音产生中最不为人所知的组成部分之一。本研究旨在填补这一空白，通过解决的作用和功能的闭锁上声道在鸟鸣。鸟类气管和口咽腔的声学特性将通过实验确定。在歌唱过程中，声道运动模式可能通过改变声道的长度或形状来调节声音，从而改变其共振或过滤特性，这将被监测和量化。将测量气管、喉部、声门、舌部、喙部和口咽部运动的声学作用。将确定可调谐声道滤波器的位置和性质，这些滤波器可以跟踪发声的基本频率，改变宽带声音的形成峰结构或抑制选定的谐波成分。我们将测试鹦鹉英语元音发音的双腔模型。这些声道运动程序的个体发育与歌唱学习的其他方面的关系将在幼鸟中进行研究。控制这些运动模式及其前运动输入的运动神经元的位置将被确定，连接声道运动控制和大脑中歌曲控制电路的中心路径将被绘制出来，来自肺部和耳鸣的反馈路径也将被绘制出来。听觉和体感反馈在提供闭环、实时调节声道运动程序方面的相对作用，可以补偿不可预测的外周扰动，也将被检查。从这些实验中获得的知识将大大提高对歌曲产生的理解，并有助于研究同样适用于语言的声音控制的基本机制，包括口吃等重要语言流利障碍的运动基础。

DESCRIPTION (provided by applicant): Songbirds and parrots are among the few animal models for human speech in which it is possible to experimentally study the basic physiological and acoustic problems involved in producing complex, learned vocalizations. The usefulness of these birds as a model for peripheral mechanisms of speech production is limited however by the fact that, although the supralaryngeal vocal tract plays a preeminent role in the articulation of speech, it is one of least well understood components of sound production in birds. This research aims to fill that gap by addressing the role and function of the suprasyringeal vocal tract in birdsong. The acoustic properties of the avian trachea and oropharyngeal cavity will be experimentally determined. Vocal tract motor patterns that may modulate sound by varying the length or shape of the vocal tract during song, thus altering its resonant or filter properties will be monitored and quantified. The acoustic role of tracheal, laryngeal, glottal, lingual, beak and oropharyngeal movements will be measured. The location and the nature of tunable vocal tract filters that may track the fundamental frequency of vocalizations, vary the formant structure of broadband sounds or suppress selected harmonic components will be determined. A two chamber model of English vowel production by parrots will be tested. The ontogenetic development of these vocal tract motor programs in relation to other aspects of song learning will be investigated in juvenile birds. The location of motor neurons controlling these motor patterns and their premotor inputs will be determined and the central pathways linking motor control of the vocal tract to the song control circuitry in the brain will be mapped, as will feedback pathways from the lungs and syrinx. The relative roles of auditory and somatosensory feedback in providing closed-loop, real-time modulation of vocal tract motor programs that may compensate for unpredictable peripheral perturbations will also be examined. The knowledge gained from these experiments will significantly improve the understanding of song production and the usefulness of birdsong for studying fundamental mechanisms of vocal control that also apply to speech, including the motor basis of important speech fluency disorders such as stuttering.