STUDIES OF TONAL INTERACTIONS IN THE AUDITORY SYSTEM

听觉系统中音调相互作用的研究

基本信息

批准号：
3395827
负责人：
ERIC JAVEL
金额：
$ 5.31万
依托单位：
FATHER FLANAGAN'S BOYS' HOME
依托单位国家：
美国
项目类别：
财政年份：
1979
资助国家：
美国
起止时间：
1979-01-01 至 1989-11-30
项目状态：
已结题

项目摘要

This is a competitive renewal of electrophysiological studies of stimulus coding in the auditory nerve and ventral cochlear nucleus of intact adult cats. There are two separate but related lines of research. The first line is a continuation of studies of neural coding of acoustic stimuli. The goals of these are to determine how nonlinear features of auditory response combine to define neural firing patterns and to examine ways that frequency and intensity information is encoded in the auditory nerve and transformed in the cochlear nucleus. Specific projects entail quantitative analyses of rate and synchrony suppression, temporal coding of frequency spectra of harmonic complexes in responses of first- and second-order auditory neurons, investigations of stimulus transforms involved in neural processing of complex tones between the auditory nerve and cochlear nucleus, and studies of excessive adaptation in auditory nerve fiber responses at high stimulus frequencies. Among the hypotheses to be tested are that stimulus waveform fine structure determines the instaneous magnitudes of both excitation and suppression, that responses of phase-sensitive cochlear nucleus neurons are quantitatively but not qualitatively different from responses of auditory nerve fibers, and that the high-frequency "hook" region of the cat cochlea is metabolically fragile. These studies contribute to the elucidation of cochlear mechanisms underlying the neural coding of complex tones and speech, to the understanding of human perception of complex tones, and to the validation of theories of frequency analysis and pitch perception. The second line of research consists of quantitative studies of neural coding of electrical stimuli delivered through a banded multi-channel cochlear implant. The goal of these is to describe thoroughly the basic properties and limitations of auditory nerve fiber responses to electrical stimuli and to infer the neurophysiological basis of behavioral performance in implanted humans. Specific projects include detailed quantitative analyses of auditory nerve fiber responses as electrical stimulus parameters are varied systematically, electrophysiological measurements of intracochlear current spread and electrode channel isolation, nerve fiber population responses to speech stimuli encoded via contemporary speech-processing schemes, and examination of alternative ways to encode electrical stimulus intensity so as to expand dynamic range. The studies are relevant to understanding the types and limits of information that cochlear implants are capable of encoding and they provide data that can guide future speech processor designs.

这是对电生理研究的竞争性更新听觉神经和腹侧耳蜗核中的刺激编码完整的成年猫。有两个单独但相关的行研究。第一行是神经研究的延续声刺激的编码。这些目标是确定听觉响应的非线性特征如何合并以定义神经发射模式并检查频率和频率的方式强度信息在听觉神经和在人工耳蜗中转化。具体项目需要速率和同步抑制的定量分析，时间分析响应中谐波复合物的频谱编码一阶和二阶听觉神经元的研究刺激转换涉及复合神经加工听觉神经和耳蜗核之间的音调，以及听觉神经纤维反应过度适应的研究在高刺激频率下。在要测试的假设中刺激波形的良好结构是否决定了激发和抑制的纯幅度，相敏感的耳蜗神经元的反应是定量但与质量上的回答没有质量不同听觉神经纤维和高频“钩子”区域猫耳蜗的代谢上脆弱。这些研究有助于阐明人工耳蜗机制复杂语调和语音的神经编码，了解人类对复杂语调的看法，以及对频率分析和音高感知理论的验证。第二道研究包括通过带子传递的电刺激的神经编码多通道人耳蜗植入物。这些目的是描述彻底地，听觉神经的基本属性和局限性纤维对电刺激的反应并推断植入行为表现的神经生理基础人类。特定项目包括详细的定量分析听觉神经纤维反应作为电刺激参数是系统的，电生理的测量值的电流传播和电极渠道隔离，神经纤维人群对语音的反应通过当代语音处理方案编码的刺激和检查编码电刺激的替代方法强度以扩大动态范围。研究很重要了解人工耳蜗的信息的类型和限制植入物能够编码，它们提供的数据可以指导未来的语音处理器设计。