ENCODING OF VOCAL SIGNALS IN THE AUDITORY SYSTEM

我们计划的目标是了解 脊椎动物听觉神经系统过程种特异性 声音信号 这项研究将集中在两个神经基础， 这些信号的识别以及潜在的机制 使其能够进行空间定位。 我们的做法是根据 主要是基于我们之前对无尾类动物的神经行为研究 （青蛙和蟾蜍）跨越过去许多年的。 既然我们有 发现，外周和中枢听觉神经系统的 不同的物种被选择性地调谐以检测特定的信号 在他们的物种特异性广告电话功能，我们希望 继续探索在各个层面的转型， 听觉系统，从而产生选择性。 我们也将 开始研究其他声音的神经编码 曲目以确定是否有单独的频道 处理这些重要的声音。 单曲录音 神经元将在第八神经，脑干核， 而在麻醉动物的前脑中， 各种声音刺激，包括自然和合成的声音 信号. 从最近的一项行为研究中，我们有证据表明， 无尾两栖类依靠声音的压力梯度机制 通过耳咽管连接到两侧的中间 以实现精确的声音定位。 中 合作研究，我们将采用激光测振仪， 描述了这部小说中涉及的生物物理学原理 阴谋 我们相信我们的整体研究结果 该计划将提供必要的洞察类似的问题， 高级脊椎动物对声音信号的感觉处理， 更难解开 我们深信 对低等、简单的发声脊椎动物的研究 模型来理解基本的过程， 在人类听觉系统中产生了听觉和语音识别 神经系统

The goal of our program is the understanding of how the vertebrate auditory nervous system processes species-specific vocal signals. This research will focus on both the neural basis of recognition of these signals as well as the underlying mechanisms that enable their spatial localization. Our approach is based primarily on our previous neurobehavioral studies of anurans (frogs and toads) spanning the past many years. Since we have found that the peripheral and central auditory nervous system of different species is selectively tuned to detect certain signal features in their species-specific advertisement calls, we wish to continue to explore the transformations at various levels of their auditory system which give rise to the selectivity. We also will begin studies of neural encoding of the other calls in their vocal repertoire to determine if there are separate channels for processing these other important sounds. Recordings from single neurons will be conducted in the eighth nerve, brainstem nuclei, and in the forebrain of anesthetized animals in response to a variety of acoustic stimuli including natural and synthetic vocal signals. From a recent behavioral study we have evidence that anurans rely on a pressure gradient mechanism involving sound coupling through their Eustachian tubes to their bilateral middle ear cavities in order to achieve accurate sound localization. In a collaborative study we will employ laser vibrometry to characterize the biophysical principles involved in this novel scheme. We believe that the results of our overall research program will provide needed insight into similar questions of sensory processing of vocal signals in higher vertebrates but which are much more difficult to unravel. We are convinced that studies of lower, simpler vocal vertebrates serve as valuable models for understanding the fundamental processes that have given rise to hearing and speech recognition in the human auditory nervous system.