Cortical mechanisms underlying vocal signal recognition

言语是人类交流的重要手段。同样，许多其他物种也使用语音通信系统来与同类交换信息。对于每个人类和非人类动物的声音交流系统来说，关键是区分特定声音信号和环境中其他声音的能力。尽管它意义重大，但我们对皮层这种识别过程背后的神经机制的了解是有限的。在这项资助的K99部分工作的基础上，我们的目标是通过对声音信号的声学结构进行参数操作，测试在对音呼叫过程中声音信号识别的知觉和神经基础。反声叫声是一种自然的、物种典型的发声行为，涉及长距离发声的相互交换。 目的1将在知觉水平上测试个体声学特征在识别物种典型发声时的功能贡献。具体地说，我们通过创建自然发声的合成复制品并操纵声学结构来测试单个特征如何对声音信号识别做出贡献。在目标2中，我们将记录参与相同发声行为的自由移动个体的神经活动，并检查前额叶和听觉皮质神经元的反应。在一组实验中，我们将记录受试者在进行对声叫声时神经元的正常活动，而在第二组实验中，我们将使用与目标1相同的程序，并在测试过程中操纵发声结构。这两种类型的实验会话将允许我们测试在对音呼叫过程中对发声的基线神经反应，但当呼叫结构的各个方面被改变时，任一区域的神经元是否显示出反应的变化。最终，需要这样的数据来阐明皮层中潜在的声音信号识别的神经过程。考虑到由于疾病或损伤而受到语音识别问题困扰的患者的数量，更全面地了解皮质是如何完成这一任务是必要的 在临床上解决这些问题。

Speech is a critical means of human communication. Likewise, numerous other species also employ vocal communication systems for exchanging information with conspeciflcs. Critical to every human and nonhuman animal vocal communication system Is the ability to distinguish conspeclfic vocal signals from other sounds in the environment. Despite its significance, our understanding of the neural mechanisms underlying this recognition process in cortex is limited. Building on work during the K99 portion of this grant, here we aim to test the test the perceptual and neural basis of vocal signal recognition during antiphonal calling, by parametrically manipulating the acoustic stmcture of a vocal signal. Antiphonal calling Is a natural, species-typical vocal behavior that Involves the reciprocal exchange of long distance vocalizations. Aim 1 will test the functional contribution of individual acoustic features for recognition of a species-typical vocalization during antiphonal calling at the perceptual level. Specifically, we vifill create synthetic replicas of naturally produced vocalizations and manipulate the acoustic structure to test how individual features contribute to vocal signal recognition. In Aim 2, we will record neural activity from freely-moving individuals engaged,in the same vocal behavior and examine the responses of neurons in the prefrontal and auditory cortex. In one set of experiments we will record the nomnal activity of neurons as subjects engage in antiphonal calling, while in a second set of experiments we will utilize the same procedure as In Aim 1 and manipulate the structure of the vocalizations during test sessions. These two types of experimental sessions will permit us to test both the baseline neural response to vocalizations during antiphonal calling, but whether neurons In either area show changes in reponses when aspects of the call structure are modified. Ultimately data such as these are needed in order to eluciate the neural processes underlying vocal signal recognition in cortex. Given the number of patients afflicted with speech recognition problems through either disease or injury, a more comprehensive understanding of how cortex accomplishes this task is necessary for addressing these Issues clinically.