Sound localization and selective auditory attention

描述(申请人提供)：本项目的总体目标是了解声音定位和选择性听觉注意的神经机制。这些结果将有助于理解大脑如何整合来自两只耳朵的听觉信息，以及如何在嘈杂的环境中将注意力引导到一个来源而不是其他来源。这种电路在我们在背景噪声存在的情况下检测信号的能力中发挥着重要作用，背景噪声是老年人听力损失的主要症状。了解神经机制将有助于助听器和治疗的设计。 有两个主要目标。首先，我们将使用两种著名的空间听觉错觉来研究空间声源在下丘的表征。实验将在清醒和训练有素的猫身上使用行为和生理相结合的准备。我们将继续我们正在进行的关于优先效应的心理物理学和生理学的实验，并开始关于弗兰森效应的一系列新的实验。这两个都是健壮的听觉错觉，可以很容易地在我们的行为准备中展示出来。其次，我们将开发一种新的心理物理学范式来研究选择性听觉注意。猫将接受训练，注意一侧的扬声器，以便进行频率辨别，而忽略来自另一侧的声音。我们假设，与不提示动物注意一侧或另一侧的试验相比，注意一侧将增强进行辨别的能力。然后，我们将使用一种创新的硅胶多通道探头从听觉皮质进行生理记录，以寻找在这项任务中注意力的调制。 空间听力和选择性注意是听觉系统的重要基本功能：人类患者的双耳功能缺陷会导致在嘈杂的房间里理解对话的相当困难，这是听力受损者最常见的主诉，可能导致严重的社交退缩。

DESCRIPTION (provided by applicant): The overall aim of this project is to understand the neural mechanisms of sound localization and selective auditory attention. These results will help to understand how the brain integrates auditory information from the two ears and how it can direct attention to one source over others in a noisy environment. This circuitry plays a major role in our ability to detect signals in the presence of background noise, which is the major symptom of elderly people with hearing loss. Understanding the neural mechanisms will help in the design of hearing aids and therapy. There are two major aims. First, we will use two well-known spatial auditory illusions to study the representation of sound sources in space in the inferior colliculus. Experiments will use a combined behavioral and physiological preparation in awake and trained cats. We will continue our on-going experiments on the psychophysics and physiology of the precedence effect and begin a new series of experiments on the Franssen effect. Both of these are robust auditory illusions that can be readily demonstrated in our behaving preparation. Second, we will develop a new psychophysical paradigm for studying selective auditory attention. Cats will be trained to attend to a speaker on one side in order to make frequency discriminations while ignoring sounds from the contralateral side. We hypothesize that attending to one side will enhance the ability to perform the discrimination as compared to trials in which the animal is not cued to attend to one side or the other. We will then make physiological recordings from the auditory cortex using an innovative silicone multichannel probe to look for modulation by attention during this task. Spatial hearing and selective attention are important basic functions of the auditory system: defects in binaural function in human patients can lead to considerable difficulty in understanding conversations in a noisy room, which is the most common complaint of the hearing-impaired and can lead to severe social withdrawal.