LIMITS OF TEMPORAL ENCODING IN THE AUDITORY SYSTEM

拟议研究的总体目标是了解 脊椎动物听觉系统编码时变生物学意义 在自然和人工产生的背景下的信息 噪声 这将通过检查时间分辨 听觉中枢单个听觉纤维和单个听觉细胞的能力 系统的无尾类（青蛙和蟾蜍）在存在窄带， 宽带和各种水平的自然背景噪声。 具体地说， 我们将讨论以下问题：（1）什么是绝对极限 单一听觉神经元对正弦刺激的锁相， 在存在掩蔽的情况下锁相恶化到什么程度 噪音？ (2)时间编码是如何受到先前暴露于 高水平的噪音（如发生在动物的栖息地）？ (3)是什么 外周听觉系统的时间整合特性 无尾两栖类，它们是否受到背景水平和特征的影响？ 噪音，它们是否反映了动物的特征 发声？最后，（4）相对空间取向如何 信号和掩蔽信号之间的相互作用影响了信号的时间分辨能力， 细胞？ 我们相信，这些研究将提供急需的洞察力， 神经基板潜在的物种特异性通信在不利的 （嘈杂的）环境，这项工作将作为一个模型， 理解人类语音感知的基本问题， 噪音的存在。

The overall goal of the proposed research is to understand how the vertebrate auditory system encodes time-varying biologically significant information in the presence of natural and artificially produced background noise. This will be accomplished by examining the temporal resolving ability of single auditory fibers and single cells in the central auditory system of anurans (frogs and toads) in the presence of narrowband, broadband, and natural background noise of various levels. Specifically, we shall address the following questions: (1) What are the absolute limits of phase-locking of single auditory neurons to sinusoidal stimuli and to what extent does phase-locking deteriorate in the presence of masking noise? (2) How is temporal coding affected by previous exposure to high-level noise (such as occurs in the animals' habitat)? (3) What are the temporal integration characteristics of the peripheral auditory system of anurans, are they affected by the level and character of the background noise, and do they reflect the characteristics of the animal's vocalizations? and finally, (4) How does the relative spatial orientation between signal and masker affect the temporal resolving ability of single cells? We believe these studies will provide much needed insight into the neural substrate underlying species-specific communication in adverse (noisy) environments, and that this work will serve as a model for the understanding fundamental problems of human speech perception in the presence of noise.