PHYSIOLOGICAL AND BEHAVIORAL STUDY OF SOUND LOCALIZATION

我们的听觉肯定是最重要的感官之一，特别是因为它允许通过语言进行交流。听觉系统还可以确定声音到达的位置。虽然只用一只耳朵就能很好地理解语音，但确定声音的空间位置需要两只耳朵，因为听觉接收器编码的是声音的频率，而不是它们的位置；需要对两只耳朵的声学输入所引起的神经信号进行中央比较。我们的长期目标是了解声音定位的神经基础。拟议培训的一个目标是获得研究猫双耳听力神经机制所需的方法、技术和技能。该培训旨在以申请者在人类观察者双耳听力行为研究方面的背景为基础。培训将包含两个具体目标，这两个目标都研究两个结构，尽管这两个结构对声音定位很重要。目的利用虚拟声学空间(VAS)技术研究三种主要声音定位线索在麻醉猫外侧上橄榄核(LSO)中的编码情况。VAS方法提供了对线索的精确独立操作，这对于确定LSO的编码策略至关重要。目的研究回声对声音定位和下丘位置编码的影响。当猫积极参与心理物理声音定位任务时，IC中的单个单元或唤醒的猫将被记录下来。培训的最终目标是开发一种综合的方法来理解听力，结合传统的行为和神经生理学方法。需要这样一种集成方法来将行为过程与它们的神经底物联系起来。

Our sense of hearing is surely one of the most important senses particularly because it allows communication through speech. The auditory system can also determine the location from which sounds arrive. While speech can be understood reasonably well using only one ear, determination of the spatial location of sound requires both ears because the auditory receptors encode the frequencies of sounds, not their locations; central comparisons of neural signals evoked by the acoustic inputs to the two ears are required. The long-term goal is to understand the neural bases of sound localization. One objective of the proposed train is to acquire the methods, techniques, and skills necessary for studying the neural mechanisms for binaural hearing in the cat. The training is designed to build on the applicant's background in behavioral studies of binaural hearing in human observers. The training will encompass two specific aims, both of which investigate two structures though to be important for sound localization. Aim I investigates how the three main sound localization cues are encoded in the lateral superior olive (LSO) of the anesthetized cat using a Virtual Acoustic Space (VAS) technique. The VAS approach affords precise independent manipulation of the cues which is crucial to determining the coding strategies of the LSO. Aim II investigates the effects of echoes on sound localization and on the coding of location in the inferior colliculus (IC). Single units in the IC or an awake cat will be recorded from while the cat is actively participating in a psychophysical sound localization task. The ultimate goal of the training is to develop an integrative approach to understanding hearing which combines traditional behavioral and neurophysiological approaches. Such an integrated approach is required to relate behavioral processes to their neural substrates.