Cortical Mechanisms Underlying Vocal Signal Recognition

描述（由申请人提供）：人类语言是我们与我们物种成员交流的主要手段。这种语音的核心是我们从环境中的其他声音中解析语音并识别单个有意义的单位（如单词）的能力。由于这个问题的重要性，我们进化出了专门的语音识别感知和神经机制。同样，许多动物通过发声与同种动物交流，因此，它们必须进化出类似的声音信号识别机制。考虑到所有哺乳动物大脑在解剖学和生理学上的相似性，对语音信号识别背后的行为和神经机制的研究可能会为人类大脑中的类似过程提供关键的见解。这项建议的目的是研究机制的声音信号识别过程中的物种特异性的声乐行为称为对唱呼叫。由于对唱呼叫仅响应于特定呼叫类型而产生，因此该行为表示自然（即未经训练的）识别系统。这项建议有四个目的。具体目标1是使用合成发声来检查特定声学特征的感知相关性，用于语音信号识别。Specific Aim 2将记录声音信号识别过程中听觉皮层中单个神经元的神经生理反应。具体目标3将扩展这些生理记录，并检查在对唱呼叫过程中听觉和前额叶皮层神经元的活动。具体目标4将采用药理学试剂来抑制皮质的特定区域，并确定这些神经元群体与语音信号识别之间的功能关系。这项提议的发现将直接关系到我们对语音识别背后的皮层机制的理解，并有助于开发各种失语症的治疗方法。与人类一样，许多动物通过发声来相互交流。通过研究动物的大脑是如何识别它们的发声的，我们将获得关于人类大脑中语音识别是如何发生的重要见解。本研究的结果适用于语言障碍治疗的研究。

DESCRIPTION (provided by applicant): Human speech is the primary means by which we communicate with members of our species. Central to this speech is our ability to parse speech from other sounds in the environment and recognize the individual meaningful units, such as words. Because significance of this problem, we evolved specialized perceptual and neural mechanisms for speech recognition. Similarly, many animals communicate with conspecifics using vocalizations and, as such, must have evolved comparable mechanisms for vocal signal recognition. Given the anatomical and physiological similarities between all mammalian brains, studies of the behavioral and neural mechanisms underlying vocal signal recognition are likely to provide key insights into the analogous process in the human brain. This proposal aims to examine the mechanisms underlying vocal signal recognition during a species-specific vocal behavior known as antiphonal calling. Since antiphonal calls are only produced in response to a particular call type, the behavior represents a natural (i.e. untrained) recognition system. This proposal has four aims. Specific Aim 1 is to use synthetic vocalizations to examine the perceptual relevance of particular acoustic features for vocal signal recognition. Specific Aim 2 will record neurophysiological responses of individual neurons in the auditory cortex during vocal signal recognition. Specific Aim 3 will extend these physiological recordings and examine the activity of neurons in the auditory and prefrontal cortex simultaneously during antiphonal calling. Specific Aim 4 will employ pharmacological agents to inhibit specific areas of the cortex and determine the functional relationship between those populations of neurons and vocal signal recognition. Findings from this proposal will have direct relevance to our understanding of the cortical mechanisms underlying speech recognition and can aid in developing treatments for various aphasic disorders. General Summary - Like humans, many animals communicate with each other by vocalizing. By studying how the brains of animals are able to recognize their vocalizations, we will gain important insights into how speech recognition occurs in the human brain. Results from this study are applicable to research on language disorder treatments.