COCHLEAR MECHANICS AND NEURAL ENCODING

这项工作的目的是导致全面的数学 耳蜗功能的模型，其可以包括以下效果：1）主动和 非线性耳蜗力学现象; 2）棘波依赖性恢复 现象;以及3）耗尽和其他耳蜗内适应现象。 所提出的耳蜗机械建模将包括主动 (but线性）机制和非线性（但被动）机制， 结合在统一的二维耳蜗和中耳模型内。 将使用马尔可夫链研究峰值依赖性恢复效应 Gaumond引入的模型，他表明听觉的概率 神经锋电位放电可以准确地表示为 仅为自上次尖峰以来的时间函数，乘以以下函数 只有刺激。 使用随机点过程扩展这项工作 这些概念将提供用于估计尖峰依赖的 以及影响棘波放电的刺激依赖性因素。 建议的实验将强调对听觉神经放电的研究 在沙鼠体内 这些研究的目的是：（1）证明 对于沙鼠，传播互调失真的存在 信号; 2）评估Gaumond的恢复校正方法， 在广泛的刺激条件下的大量神经纤维;以及 3)获得激励条件下的激励函数估计值（EFE） 旨在测试机械和换能模型的预测。 这项工作应有助于提供一个概念框架， 直接和非侵入性研究的实验结果， 耳蜗 提高我们对这些机制的理解， 耳蜗的编码功能应该有助于为 周边听觉功能障碍的表征，并为设计 假肢设备和助听器。 神经锋电位分析新方法的发展， 这项建议的主要目标，应该证明是有价值的， 研究人员的听觉系统，也可能适用于研究 神经系统的其他部分。

The work proposed is intended to lead toward a comprehensive mathematical model for cochlear function that can include the effects of: 1) active and nonlinear cochlear mechanical phenomena; 2) spike-dependent recovery phenomena; and 3) depletion and other intra-cochlear adaptation phenomena. The cochlear mechanical modeling proposed would include both the active (but linear) mechanisms and the nonlinear (but passive) mechanisms, combined within a unified two-dimensional cochlea and middle ear model. Spike-dependent recovery effects would be studied using a Markov Chain model introduced by Gaumond, who showed that the probability of an auditory nerve spike discharge could be accurately represented as the product of a function of time since last spike only, multiplied by a function of stimulus only. Extensions to this work using stochastic point process concepts will provide improved methods for estimating the spike-dependent and stimulus-dependent factors affecting spike discharges. Experiments proposed would emphasize the study of auditory nerve discharges in the gerbil. Objectives of these studies would be: 1) to demonstrate for the gerbil the existence of propagating intermodulation distortion signals; 2) to evaluate the recovery-correction method of Gaumond for a large number of nerve fibers under a wide range of stimulus conditions; and 3) to obtain Excitation Function Estimates (EFE) under stimulus conditions intended to test the predictions of mechanical and transduction models. This work should help to provide a conceptual framework for the integration of experimental findings from direct as well as non-invasive studies of the cochlea. Improvements in our understanding of the mechanisms and the encoding function of the cochlea should help to provide a firmer basis for the characterization of peripheral auditory misfunction, and for the design of prosthetic devices and hearing aids. Development of new methods for nerve spike analysis, incidental to the primary objectives of this proposal, should prove valuable to other researchers of the auditory system and may also be applicable to studies of other parts of the nervous system.