Mechanisms of Oculomotor Influences on Hearing

项目摘要 听觉是一个与视觉协同工作的积极过程。如何以及在哪里的活动过程中， 听觉对视觉交互作用的贡献目前是未知的。一种可能性是， 相互作用发生在听觉通路的最早阶段-耳内。几种类型的物理 位于耳内的致动器，即中耳肌肉和外毛细胞， 鼓膜运动并产生内源性阈下声音，称为耳声发射。我们 最近发现了一种新的声音：眼球运动相关的鼓膜振荡，或EMREO。 这一发现暗示了耳朵的内部驱动系统以多模态处理的形式存在。 然而，产生EMREO的机制目前尚不清楚。了解这个机制 将阐明眼动对听觉的功能影响以及听觉如何协调 有远见。 我们将在动物模型中测试这些致动器对EMREO的贡献， 每种成分通过手术或通过耳毒性物质的局部应用。我们将比较 这些研究与在患有中耳肌肉或外耳道损伤的人类听力损失患者中获得的结果一致。 毛细胞功能障碍我们假设中耳肌肉和外毛细胞协同工作， 生产EMREO，任何致动器系统的功能障碍都会导致 EMREO。这种功能障碍可能的知觉后果也将被探讨。 总之，这些实验将揭示大脑如何调节听觉传导系统 当眼睛运动改变眼睛和耳朵的相对位置时。眼球信号发生在 听觉通路的入口代表了我们对范围的理解的根本转变 以及听觉中的机制，特别是听觉系统如何与视觉系统相互作用， 系统这些发现将与涉及耳朵内部致动器的各种听力障碍有关 或自上而下的控制，包括感音神经性听力损失和年龄相关性听力损失，以及 复杂的感觉/认知综合征，如阅读障碍和自闭症。

PROJECT SUMMARY Hearing is an active process that works in concert with vision. How and where the active processes in hearing contribute to interactions with vision is presently unknown. One possibility is that these interactions occur at the earliest stages of the auditory pathway – within the ear. Several types of physical actuators located inside the ear, namely the middle ear muscles and outer hair cells, collectively adjust eardrum motion and generate endogenous, subthreshold sounds known as otoacoustic emissions. We recently discovered a new type of such sounds: eye movement-related eardrum oscillations, or EMREOs. This discovery implicates the ear’s internal actuation systems in a form of multimodal processing. However, the mechanism that generates EMREOs is presently unknown. Understanding this mechanism will shed light on the functional consequences of eye movements for hearing and how hearing coordinates with vision. We will test the contributions of these actuators to EMREOs in an animal model, selectively interrupting each component surgically or via local application of ototoxic substances. We will compare the results of these studies to results obtained in human hearing loss patients suffering from middle ear muscle or outer hair cell dysfunction. We hypothesize that the middle ear muscles and outer hair cells work in concert to produce the EMREO, and that dysfunction of any of the actuator systems will lead to anomalies in EMREOs. Possible perceptual consequences of such dysfunction will also be probed. Together, these experiments will shed light on how the brain adjusts the auditory transduction system when eye movements shift the relative alignments of the eyes and ears. That oculomotor signals occur at the very gateway of the auditory pathway represents a fundamental shift in our understanding of the scope and mechanisms employed in hearing, and in particular how the auditory system interfaces with the visual system. The findings will be relevant to a variety of hearing disorders involving the ears’ internal actuators or their top-down control, including sensorineural hearing loss and age-related hearing loss, as well as complex sensory/cognitive syndromes such as dyslexia and autism.