权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Effects of Spectral Context on Responses in Auditory Cortex

频谱背景对听觉皮层反应的影响

基本信息

批准号：
7845125
负责人：
DENNIS L BARBOUR
金额：
$ 0.61万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-06-01 至 2009-10-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): This project addresses our long-term goal to improve our understanding of the mechanisms underlying environmental and communication sound encoding in the mammalian auditory system. Extracting behaviorally relevant information from noisy acoustic signals remains a considerable challenge for engineers of artificial acoustic processing systems, while biological auditory systems seem exquisitely well-suited to such tasks. Understanding the normal encoding of sounds in biological systems will enable us to design more functional artificial sound processors such as hearing aids or hearing-assist devices, as well as to appropriately design auditory neural prostheses intended to interface with malfunctioning human auditory areas. We study common marmosets (Callithrix jacchus) because they are one of the most vocal primate species and because their auditory cortical structure bears considerable similarity to that of humans. Marmoset auditory cortical neurons have been shown to exhibit complex, often nonlinear, responses to wideband sounds such as vocalizations. Most such neurons respond to narrowband sounds only over a relatively narrow range of frequencies. We seek to establish through a series of experiments that neuronal inputs wide- ranging in frequency are responsible for at least some of the previously observed complex responses. The project's research goals will be pursued through the following specific aims: 1) Test the hypothesis that spectral contrast tuning is mediated, in part, by frequencies outside a neuron's classically defined receptive field. Such a finding would provide stronger evidence that these neurons, previously described by the investigator, operate preferentially in conditions of wideband background noise. 2) Test the hypothesis that natural, wideband sounds elicit spikes with more information content than when these sounds are filtered to match the neurons' classical receptive field, particularly for contrast-tuned neurons. Visual cortex neurons exhibit this property, which reveals that the neurons have response properties well-matched to natural visual scenes. If confirmed, these hypotheses would imply that biological auditory systems may be integrating sound energy over a wider frequency range than has been previously estimated. Consequently, artificial systems designed for individuals with hearing loss may be able to exploit these biologically-inspired, wideband coding schemes to ultimately improve these individuals' ability to communicate in real-world situations. This project addresses our long-term goal to improve our understanding of the mechanisms underlying environmental and communication sound encoding in the mammalian auditory system by evaluating how neurons in primate auditory cortex integrate sound energy over a wide range of frequencies. Understanding biological frequency integration may aid engineers in improving auditory prosthesis devices to improving sound encoding in natural everyday environments such as in a noisy room.

描述（由申请人提供）：该项目解决了我们的长期目标，以提高我们对哺乳动物听觉系统中环境和通信声音编码机制的理解。从嘈杂的声学信号中提取行为相关信息仍然是人工声学处理系统工程师面临的一个相当大的挑战，而生物听觉系统似乎非常适合这样的任务。了解生物系统中声音的正常编码将使我们能够设计更多功能的人工声音处理器，如助听器或听力辅助设备，以及适当设计听觉神经假体，用于与功能障碍的人类听觉区域进行交互。我们研究普通的绒猴（Callithrix jacchus），因为它们是最能发声的灵长类动物之一，而且它们的听觉皮层结构与人类相当相似。绒猴听觉皮层神经元对诸如发声的宽带声音表现出复杂的、通常是非线性的反应。大多数这样的神经元只对相对较窄的频率范围内的窄带声音作出反应。我们试图通过一系列的实验来确定，神经元的输入频率范围很广，至少是以前观察到的一些复杂反应的原因。该项目的研究目标将通过以下具体目标来实现：1）测试光谱对比度调谐部分由神经元经典定义的感受野之外的频率介导的假设。这一发现将提供更有力的证据，证明研究人员先前描述的这些神经元优先在宽带背景噪声条件下工作。2)测试这样一个假设，即自然的、宽带的声音比当这些声音被过滤以匹配神经元的经典感受野时，特别是对于对比度调谐的神经元，会引起具有更多信息内容的尖峰。视觉皮层神经元表现出这种特性，这表明神经元具有与自然视觉场景匹配良好的响应特性。如果得到证实，这些假设将意味着生物听觉系统可能在比先前估计的更宽的频率范围内整合声能。因此，为听力损失的个体设计的人工系统可能能够利用这些生物启发的宽带编码方案，以最终提高这些个体在现实世界情况下的通信能力。这个项目解决了我们的长期目标，以提高我们的理解的机制，在哺乳动物听觉系统的环境和通信声音编码通过评估灵长类动物听觉皮层神经元如何整合在很宽的频率范围内的声能。了解生物频率整合可以帮助工程师改进听觉假体设备，以改善自然日常环境中的声音编码，例如在嘈杂的房间中。