Effects of Spectral Context on Responses in Auditory Cortex

频谱背景对听觉皮层反应的影响

• 批准号: 7354797
• 负责人: DENNIS L BARBOUR
• 金额: $ 7.43万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-02-09 至 2010-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7354797
• 关键词: Acoustics; Action Potentials; Address; Affect; Animal Vocalization; Auditory; Auditory area; Auditory system; Behavior; Biological; Callithrix; Callithrix jacchus jacchus; Class; Cochlear Implants; Code; Communication; Complex; Condition; Devices; Engineering; Environment; Exhibits; Frequencies; Goals; Hearing; Hearing Aids; Human; Individual; Location; Mammals; Measures; Mediating; Neurons; Noise; Outcome; Primates; Process; Property; Protocols documentation; Purpose; Range; Rate; Research Personnel; Research Project Grants; Scheme; Series; Shapes; Signal Transduction; Speech; Standards of Weights and Measures; Stimulus; Structure; System; Testing; Ursidae Family; Visual; Visual Cortex; design; digital; hearing impairment; improved; insight; neural prosthesis; novel; receptive field; research study; response; sound; vocalization

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，即提高我们对哺乳动物听觉系统中环境和通信声音编码的机制的理解。对于人工声学处理系统的工程师来说，从噪声声信号中提取行为相关信息仍然是一个相当大的挑战，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，例如助听器或助听设备，以及适当地设计旨在与出现故障的人类听觉区域连接的听觉神经假体。我们研究普通狨猴（Callithrix jacchus），因为它们是声音最大的灵长类动物之一，而且它们的听觉皮层结构与人类相当相似。狨猴听觉皮层神经元已被证明对宽带声音（例如发声）表现出复杂且通常是非线性的反应。大多数此类神经元仅对相对较窄的频率范围内的窄带声音做出反应。我们试图通过一系列实验来确定频率范围广泛的神经元输入至少对一些先前观察到的复杂反应负责。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，证明研究人员之前描述的这些神经元优先在宽带背景噪声的条件下运作。 2) 测试以下假设：与经过过滤以匹配神经元的经典感受野的声音相比，自然的宽带声音会引发更多信息内容的尖峰，特别是对于对比度调整的神经元。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非常匹配的响应特性。如果得到证实，这些假设将意味着生物听觉系统可能会在比之前估计的更宽的频率范围内整合声能。因此，为听力损失者设计的人工系统可能能够利用这些受生物学启发的宽带编码方案，最终提高这些人在现实世界中的沟通能力。该项目解决了我们的长期目标，即通过评估灵长类动物听觉皮层中的神经元如何整合各种频率的声音能量，提高我们对哺乳动物听觉系统中环境和通信声音编码的机制的理解。了解生物频率集成可以帮助工程师改进听觉假体设备，以改善自然日常环境（例如嘈杂的房间）中的声音编码。