Neural basis of vocal signal recognition during natural communication

描述（由申请人提供）：人类和非人类灵长类动物使用发声与同种动物交流。为了在这种媒介中成功地进行通信，听众必须能够识别语音信号（例如人类的单词），并将其从声学环境中过多的其他生物和非生物声音中解析出来。识别特定物种的声音信号并不是声音信号识别的最终结果，而只是一个更复杂过程的一部分。像其他对象一样，声音信号包括反映呼叫者的社会维度的许多类别，例如个人身份、性别、方言， 等这些社会类别被编码在发声的声学结构中，这是由于呼叫者的声音中的特质，并且已知在人类和非人类灵长类动物的声音相互作用中具有感知意义。虽然语音识别的神经基础已被广泛研究，使用各种神经成像技术和患者，少得多的是知道其潜在的细胞机制。鉴于声音感知的相似性和听觉系统神经解剖学的同源性，非人灵长类动物是一个很好的模型，用于解释灵长类动物新皮层中声音信号识别的神经机制。几乎所有早期的非人类灵长类动物皮层发声处理的神经研究都涉及到向受限制的动物提供发声样本的实验。然而，沟通是一个内在的互动过程，涉及同种之间的信号交换。这项建议的目的是研究自然行为的普通绒猴的声音信号识别，而他们从事对唱呼叫，一种声乐行为的特点是相互交换的发声。由于绒猴只会对特定的呼叫类型做出回应，因此这种行为代表了一种自然的（即未经训练的）识别系统，并且特别适合于探索自然交流期间社会分类的神经基础，原因如下三个。首先，以前的工作表明，社会类别的呼叫者影响的动态antiphonal调用。其次，我们开发了新颖的交互式播放软件，使我们能够在实验条件下引起这种声音反应。第三，我们可以记录受试者自由移动时绒猴前额叶皮层单个神经元的活动。这三个组成部分是实现本建议三个目标的潜在有力办法。具体目标1是结合联合收割机单单位神经生理学和组织学来表征绒猴额叶皮层用于声音交流的功能神经解剖学。这一目标将为所有后续的生理学奠定基础，无论是在这个建议中，还是在未来。具体 目标2旨在通过向受试者提供综合操纵的发声来广泛测试社会分类的感知基础。具体目标3建立在本建议的上述目标的基础上，通过使用目标1的神经解剖学位置和目标2的感知发现来测试对唱呼叫期间社会分类的神经基础。

DESCRIPTION (provided by applicant): Human and nonhuman primates communicate with conspecifics using vocalizations. For communication in this medium to be successful, listeners must be able to recognize vocal signals (e.g. words for humans) and parse them from the plethora of other biotic and abiotic sounds in the acoustic environment. Rather than be the culmination of vocal signal recognition, identifying species-specific acoustic signals is only one part of a more complex process. Like other objects, vocal signals comprise a number of categories that reflect social dimensions of the caller, such as individual identity, sex, dialect, etc. These social categories are encoded in the acoustic structure of the vocalization due to idiosyncrasies in the caller's voice and are known to be perceptually meaningful in both human and nonhuman primate vocal interactions. While the neural basis of speech recognition has been extensively studied using various neuroimaging techniques and patients, much less is known about its underlying cellular mechanisms. Given similarities in vocal perception and homologies in the auditory system neuroanatomy, nonhuman primates represent an excellent model for explicating the neural mechanisms underlying vocal signal recognition in primate neocortex. Nearly all earlier neural studies of vocalization processing in nonhuman primate cortex involve experiments in which vocalization exemplars are presented to restrained animals. Communication, however, is an inherently interactive process involving the exchange of signals between conspecifics. The aim of this proposal is to examine vocal signal recognition in naturally behaving common marmosets while they engage in antiphonal calling, a vocal behavior characterized by the reciprocal exchange of vocalizations. Since marmosets will only produce an antiphonal call in response to a particular call type, this behavior represents a natural (i.e. untrained) recognition system and is uniquely suited to explore the neural basis of social categorization during natural communication for the following three reasons. First, previous work shows that social categories of callers affect the dynamics of antiphonal calling. Second, we developed novel, interactive playback software that allows us to elicit this vocal response under experimental conditions. And third, we can record the activity of single neurons in marmoset prefrontal cortex while subjects are freely-moving. These three components represent a potentially powerful approach to addressing the three aims of this proposal. Specific Aim 1 is to combine single-unit neurophysiology and histology to characterize the functional neuroanatomy of marmoset frontal cortex for vocal communication. This aim will establish a foundation for all subsequent physiology, both in this proposal and further in the future. Specific Aim 2 seeks to extensively test the perceptual basis of social categorization by presenting subjects with synthetically manipulated vocalizations. Specific Aim 3 builds on the preceding aims of this proposal by testing the neural basis of social categorization during antiphonal calling using the neuroanatomical locations of Aim 1 and the perceptual findings of Aim 2.