LIMITS OF TEMPORAL ENCODING IN THE AUDITORY SYSTEM

拟议研究的总体目标是了解 脊椎动物的听觉系统编码时变的生物学意义 在存在自然和人工产生的背景的情况下的信息 噪音。这将通过检查时间分辨率来实现 中枢听觉中单纤维和单细胞的能力 无尾两栖类(青蛙和蟾蜍)在窄带存在时的系统， 宽带，以及各种级别的自然背景噪声。具体来说， 我们将回答以下问题：(1)绝对限制是什么 单个听神经元对正弦刺激的锁相效应 在存在屏蔽的情况下，锁相恶化的程度有多大 噪声？(2)以前接触过的环境对时间编码有何影响 高水平的噪音(如动物栖息地)？(3)什么是 外周听觉系统的时间整合特征 无尾两栖动物，它们是否受到背景的水平和特征的影响 噪音，以及它们是否反映了动物的 发声？最后，(4)相对空间方位如何 信号与掩码之间的关系影响信号的时间分辨能力 细胞？我们相信这些研究将提供亟需的洞察 逆境中物种特异性交流的神经底物 (嘈杂的)环境，这项工作将作为 理解人类言语感知的基本问题 存在噪音。

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.