STUDIES ON BRAIN STEM MECHANISMS OF SPATIAL HEARING

这个项目的长期目标是彻底了解 听性脑干双耳相互作用的神经机制 核团，特别是当它们与声音局部化和其他 双耳听力的几个方面。该项目的基本方法包括 细胞外单个神经元的电生理记录 技术，同时使用合成的复杂刺激的广泛阵列 在电脑控制下。刺激物是精心挑选的，以帮助 阐明神经功能和/或模拟心理物理现象 重要的是要解释生理结果并将其与 心理物理学。本申请建议继续进行 急性研究以及开始对声音的行为研究 本地化。有三个总体目标。一(1)是研究 优先效应的生理相关性通过记录在 下丘，以及听神经和耳蜗处 使用耳机和自由场刺激。潜在的 假说是下丘某些细胞的放电 与声源的感知位置有关。两(2)是 耳下区耳间频谱差异的编码研究 使用项目中记录的头部相关传递函数的丘脑 本计划的第四部分。这些研究将允许直接关联 细胞对自由场刺激的反应，如与头部相关的 传递函数，以及传统的双耳交互测量 在耳机下测量。三(3)是发展新的 训练猫看声源和使用声源的行为准备 这为一些重要的研究做好了准备。美国人的运动 将研究猫科动物在主动定位期间的耳廓，确认 虚拟空间刺激的感知将通过传递 通过耳机给猫的信号是本地化的声音，程度 对猫的优先效应将得到测试，以及 记录将由下丘中的单个细胞进行 被认为对编码声音的方向很重要 主动本地化。空间听力是一项重要的基础性功能 听觉系统：人类患者的双耳功能缺陷可能 导致在检测嵌入噪声中的信号时相当困难， 例如，在嘈杂的房间里理解对话，这可能是 MST是听障人士的常见抱怨，可导致严重的社会问题 戒烟。

The long-term objective of this project is a thorough understanding of the neural mechanisms of binaural interaction in the auditory brainstem nuclei, particularly as they relate to sound localization and other aspects of binaural hearing. The basic approach in this project entails electrophysiological recordings from single neurons using extracellular techniques while employing a broad array of complex stimuli synthesized under computer control. The stimuli are carefully chosen to help elucidate neuronal function and/or to mimic psychophysical phenomena for it is important to interpret and relate physiological results to psychophysics. The present application proposes to continue on-going acute studies as well as to begin behavioral studies of sound localization. There are three general aims. One (1) is to study the physiological correlates of the precedence effect by recordings in the inferior colliculus, as well as in the auditory nerve and cochlear nucleus, using both earphones and free field stimulation. The underlying hypothesis is that the discharge of some cells in the inferior colliculus is related to the perceived location of the sound source. Two (2) is to study the encoding of interaural spectral differences in the inferior colliculus using the head-related transfer functions recorded in project IV of this Program. These studies will allow direct correlation of the responses of cells to free field stimuli, as simulated by the head-related transfer functions, and to traditional measures of binaural interaction measured under headphones. Three (3) is the development of a new behavioral preparation to train cats to look at sound sources and to use this preparation for a number of important studies. The movements of the cats pinnae during active localization will be studied, confirmation of the perception of the virtual space stimuli will be sought by delivering the signals via headphones to cats that are localizing sounds, the degree to which the precedence effect holds for cats will be tested, and recordings will be made from single cells in the inferior colliculus that are thought to be important for encoding the direction of a sound during active localization. Spatial hearing is an important basic function of the auditory system: defects in binaural function in human patients can lead to considerable difficulty in detecting signals embedded in noise, such as understanding a conversation in a noisy room, which is perhaps the mst common complaint of the hearing-impaired and can lead to severe social withdrawal.