Multisensory Processes in the Mechanics of Hearing

项目总结 视觉帮助我们听力。例如，唇读有助于言语理解，而视觉线索则是思维方式 对学习如何本地化声音至关重要。视觉-听觉相互作用通常被认为是 一种皮质现象，但越来越多的证据表明，感觉系统之间的串扰开始 早在大脑皮层阶段之前。在这个项目中，我们研究视觉对听觉处理的影响 在它们出现的最早时刻：在耳朵里。 听觉通路具有用于调制传入听觉信号的处理的健壮系统 外毛细胞和中耳肌肉的运动动作。这些结构处于下降状态 来自大脑的控制，为视觉相关信号影响听觉处理提供了潜在的途径。 这个系统受眼睛运动的影响：我们最近报告了一种以前未知的 与眼跳发生时间相关的鼓膜振荡，在没有眼跳的情况下发生 传来的声音。 我们假设，这种与眼动相关的外周听觉效应背后的过程 处理在协调伴随的视觉和听觉空间信号的差异方面发挥了作用 眼球运动。我们将通过确定眼球运动特性决定什么来检验这一假设 鼓膜振荡的特性，在眼球运动系统中，有助于 这种效应是如何产生的；以及眼球运动相关的外周处理是如何结合 视觉和听觉空间之间的映射的变化。 总之，这些实验将阐明大脑是如何调整其听觉输入以与 视觉系统。在听觉通路的入口处发现多感官信号 表示我们对范围和机制的理解发生了根本转变，不仅在 多感官整合的服务，但也是在什么以前被认为是单模式的处理。 这些发现将与听力障碍和其他涉及视觉的疾病相关 以及听力障碍，如阅读困难、听觉处理障碍、梅尼埃病、自闭症、 精神分裂症，以及与年龄相关的认知障碍。

PROJECT SUMMARY Vision helps us hear. For example, lip reading aids speech comprehension, and visual cues are thought to be critical for learning how to localize sounds. Visual-auditory interactions are usually considered to be a cortical phenomenon, but mounting evidence suggests that cross-talk between sensory systems begins well before the cortical stage. In this project, we investigate visual influences over the auditory processing at the earliest point that they occur: in the ear. The auditory pathway has a robust system for modulating the processing of incoming auditory signals via the motoric actions of outer hair cells and middle ear musculature. These structures are under descending control from the brain, providing potential routes for visual-related signals to influence auditory processing. This system is affected by movements of the eyes: we have recently reported a previously unknown oscillation of the eardrum that is time locked to the occurrence of saccades and occurs in the absence of a delivered sound. We hypothesize that the processes that underlie this eye movement-related effect on peripheral auditory processing play a role in reconciling the disparities in visual and auditory spatial signals that accompany eye movements. We will test this hypothesis by determining what eye movement properties determine the properties of the eardrum oscillation, where in the oculomotor system commands that contribute to this effect originate; and how eye-movement related peripheral processing changes in conjunction with changes in the mapping between visual and auditory space. Together, these experiments will shed light on how the brain tunes its auditory input to coordinate with the visual system. The discovery of multisensory signals at the very gateway of the auditory pathway represents a fundamental shift in our understanding of the scope and mechanisms employed not only in service of multisensory integration, but also on what was previously supposed to be unimodal processing. The findings will be relevant to disorders involving hearing as well as other conditions that involve visual and auditory deficits, such as dyslexia, auditory processing disorder, Meniere's disease, autism, schizophrenia, and age-related cognitive impairments.