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）：该项目旨在解决我们对哺乳动物听觉系统中环境和通信声音基础机制的理解的长期目标。从嘈杂的声学信号中提取行为相关的信息对于人工声学处理系统的工程师来说仍然是一个巨大的挑战，而生物听觉系统似乎非常适合此类任务。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，例如助听器或助听器设备，以及适当设计的听觉神经假体，旨在与故障与人体听觉区域进行交互。我们研究常见的摩尔果（Callithrix jacchus），因为它们是最具声音的灵长类动物之一，并且因为它们的听觉皮质结构与人类具有相似的相似性。 Marmoset听觉的皮质神经元已显示出对宽带声音（例如发声）的复杂反应。大多数此类神经元仅在相对狭窄的频率范围内对窄带响应。我们试图通过一系列实验来确定频率广泛的神经元输入是至少某些先前观察到的复杂响应的原因。该项目的研究目标将通过以下特定目的来实现：1）检验以下假设：光谱对比度的部分是通过神经元经典定义的接受场之外的频率介导的。这样的发现将提供更有力的证据，即这些神经元先前由研究者描述，优先在宽带背景噪声的条件下运作。 2）检验以下假设：自然，宽带声音引起的峰值具有更多的信息含量，而这些声音被过滤以匹配神经元的经典接受场，尤其是对于对比度调节的神经元。 Visual Cortex神经元表现出该特性，该特性表明神经元具有与自然视觉场景相匹配的响应特性。如果得到证实，这些假设将暗示生物听觉系统可能比以前估计的频率更广泛地整合声音。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受生物启发的宽带编码方案，最终提高这些人在现实世界中进行交流的能力。该项目通过评估灵长类动物听觉皮层中的神经元如何在广泛的频率中整合声音能量的方式来解决我们对哺乳动物听觉系统中环境和通信声音基础机制的理解，以提高我们对我们对哺乳动物听觉系统中的机制的理解的理解。了解生物学频率整合可以帮助工程师改善听觉假体设备，以改善在诸如嘈杂室里的自然日常环境中编码的声音编码。