Auditory-Vocal Processing in a Behavioral Context

描述（由申请人提供）：使人类和其他一些物种能够使用习得的声音信号（例如语音）进行交流的神经生物学适应性尚未得到很好的理解。成像数据表明，语音不仅是侧化的，而且在听觉（腹侧，颞侧）流和听觉-运动（背侧，额侧）流中进行处理，听觉-运动（背侧，额侧）流将声音映射到前运动发声区域。在神经回路水平上对这一建议进行神经生物学研究需要建立一个参与声音学习的动物模型。目前的项目将使用鸣禽模型来详细研究双流假说，因为1)在为数不多的动物类群中，鸣禽是最容易研究的，它们能像人类一样学会发出用于社会交流的声音信号；鸣禽前脑的两个解剖学和功能上截然不同的区域处理歌声的方式似乎是不同的，就像说话一样。我们建议建立一个新的范式，使用清醒和行为的鸣禽，通过记录听觉和发声前运动区域来评估暴露历史和行为显著性对听觉加工的影响，听觉和发声前运动区域可能在复杂通信信号的感知加工和发声产生中发挥重要作用。为此，我们将使用三种方法在生理记录之前和期间操纵行为显著性。1)鸟类将在行为范式中学习辨别其他个体的独特歌曲，随后在听觉和运动结构中进行双侧急性多电极记录，以测试行为强化对训练刺激反应的影响2)长期植入以听觉和运动结构为目标的电极的鸟类将进行辨别训练，使与行为学习相关的感觉处理变化能够实时研究。3)开发一种将识别训练与头部固定鸟类急性神经生理记录相结合的新方法。结合前两种方法的优点，这将使在行为过程中来自不同神经结构的高质量同时记录成为可能。拟议的工作在两个方面意义重大。首先，它的目的是利用现有的方法来收集行为过程中听觉区域的神经数据，并开发一种新的范式，用于在清醒的鸣禽执行识别任务时进行多电极记录。这种创新的方法将允许对听觉处理进行实时评估，听觉处理是识别相关声音交流信号的基础。其次，这些方法将首次实现在任务执行过程中同时记录感觉结构和声音运动通路，这可能在仅在任务环境中揭示的感知处理中发挥重要作用，正如研究表明的那样，言语产生和感知功能重叠。这将测试双流提议，并可能揭示与正常和异常语音处理相关的重要原则。

DESCRIPTION (provided by applicant): The neurobiological adaptations that enable humans and a few other species to communicate using learned vocal signals, e.g. speech, are not well understood. Imaging data have led to the proposal that speech is not only lateralized, but also processed both in an auditory (ventral, temporal) stream that serves acoustic object identification and in an auditory-motor (dorsal, frontal) stream that maps sounds onto pre-motor vocal areas. Neurobiological investigation of this proposal at the circuit level requires an established animal model that engages in vocal learning. The current project will use the songbird model to study the dual stream proposal in detail because 1) songbirds are the most easily studied of the very few animal taxa that learn to produce vocal signals for social communication as humans do; and 2) songs appear to be processed differently in two anatomically and functionally distinct areas of the songbird forebrain, as seems true for speech. We propose to develop a novel paradigm, using awake and behaving songbirds, to evaluate the effects of exposure history and behavioral salience on auditory processing by recording in both the auditory and vocal pre-motor areas, which may play an important role in perceptual processing of complex communication signals as well as in vocal production. To this end, we will manipulate behavioral salience before and during physiological recordings, using three approaches. 1) Birds will learn to discriminate the unique songs of other individuals in a behavioral paradigm, followed by acute multielectrode recording in auditory and motor structures bilaterally to test the effects of behavioral reinforcement on responses to training stimuli 2) Birds with chronically implanted electrodes that target auditory and motor structures will undergo discrimination training, enabling changes in sensory processing associated with behavioral learning to be studied in real time. 3) A novel method for combining discrimination training with acute neurophysiological recording in head-fixed birds will be developed. This will enable high quality simultaneous recording from different neural structures bilaterally during behavior, combining the strengths of the first two methods. The proposed work is significant in two ways. First, it aims to both exploit existing methods for collecting neural data from auditory areas during behavior and also to develop a novel paradigm for multielectrode recording from awake songbirds during performance of a discrimination task. This innovative approach will allow for real time assessment of the auditory processing that underlies the discrimination of relevant vocal communication signals. Second, these approaches will for the first time enable simultaneous recording during task performance from both sensory structures and the vocal motor pathway, which may have an important role in perceptual processing that is only revealed in a task context, as has been suggested by studies showing overlap of speech production and perceptual function. This will test the dual stream proposal and may reveal important principles relevant to both normal and abnormal speech processing.