Cortical Mechanisms Underlying Vocal Signal Recognition

描述(申请人提供)：人类语言是我们与人类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元的能力，例如单词。由于这个问题的重要性，我们进化出了专门的感知和神经机制来进行语音识别。同样，许多动物使用发声与同种生物交流，因此，肯定进化出了类似的声音信号识别机制。鉴于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类似的过程提供关键的见解。这项建议旨在研究在一种特定物种的声音行为中，声音信号识别的潜在机制，这种声音行为被称为对音叫声。由于仅响应于特定呼叫类型而产生对音呼叫，因此该行为代表了自然(即，未经训练的)识别系统。这项提议有四个目标。具体目标1是使用合成发声来检查特定声学特征对于声音信号识别的知觉相关性。特定目标2将记录在声音信号识别过程中听觉皮质中单个神经元的神经生理反应。特殊目标3将扩展这些生理记录，并同时检测对声叫声时听觉和前额叶皮质神经元的活动。特定目标4将使用药理学药物来抑制皮质的特定区域，并确定这些神经元群体与声音信号识别之间的功能关系。这一提议的发现将与我们对语音识别背后的皮质机制的理解直接相关，并有助于开发各种失语症的治疗方法。概述--像人类一样，许多动物通过发声相互交流。通过研究动物的大脑如何识别它们的发声，我们将对人类大脑如何进行语音识别获得重要的见解。本研究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.