Vestibular Contributions to Estimated Head Motion and Orientation

由前庭迷路提供的关于头部运动和方向的信息受到以下因素的限制： 几个特征，但大脑仍然能够产生相对准确的感知和眼球运动， 前庭刺激时的反应。前庭系统必须处理的一个主要问题是噪音 神经处理的各个方面所固有的。在本提案中，我们将使用几种新颖的技术（包括 非人灵长类前庭心理物理学，半规管高频电刺激 传入，以及前庭眼反射（VOR）阈值和中枢前庭噪声的测量）， 研究噪音如何影响负责前庭介导眼球运动的中央处理 和知觉反应。更具体地说，我们提出了三个假设，我们将在三个具体的测试， 目标是专注于大脑优化感知和眼动反应的能力， 迷宫提供的信息的局限性。在前两个具体目标中，我们将改变 通过使用对椎管壶腹的甚高频电刺激来对椎管传入信号施加噪声 神经叠加在正常的通道传入线索。我们将研究如何噪音对运河旋转 输入影响知觉和眼动反应，并预测当噪声增加速度时， 在大脑中的存储集成器将变得不那么有效（目的1），并且对低频的误解 倾斜时的平移将被加重（目标2）。在具体目标3中，我们将研究以下假设： 外周前庭消融通过诱导不同程度的外周前庭噪声， 氨基糖苷类药物引起的前庭功能减退以及VOR和行为指标的变化 前庭噪声，基于固定点状目标时眼速方差的变化， 头部静止。总之，这些实验将有助于回答长期存在的基本问题， 关于前庭信息是如何集中处理的，这项工作不仅将提高对 正常的前庭生理学，但也可能有助于阐明机制负责异常 感觉和眼球运动反应，发生与周围和中央前庭障碍 系统

The information about head motion and orientation provided by the vestibular labyrinth is constrained by several features, but the brain is still able to generate relatively accurate perceptual and eye movement responses during vestibular stimulation. One major problem the vestibular system must deal with is the noise inherent in all aspects of neural processing. In this proposal we will use several novel techniques (including vestibular psychophysics in non-human primates, high-frequency electrical stimulation of semicircular canal afferents, and measures of the vestibulo-ocular reflex (VOR) threshold and central vestibular noise) to investigate how noise affects the central processing that is responsible for vestibular-mediated eye movement and perceptual responses. More specifically, we propose three hypotheses which we will test in three specific aims that focus on the brain's ability to optimize perceptual and eye movement responses despite the limitations in the information provided by the labyrinth. In the first two specific aims, we will vary the amount of noise on the canal afferent signals by using very high-frequency electrical stimulation of the canal ampullary nerves superimposed on the normal canal afferent cues. We will investigate how noise on the canal rotational inputs affects perceptual and eye movement responses, and predict that when the noise increases the velocity storage integrator in the brain will become less effective (aim 1) and that the misperception of low-frequency translation as tilt will be accentuated (aim 2). In specific aim 3, we will investigate the hypothesis that peripheral vestibular ablation increases central vestibular noise by inducing different degrees of peripheral vestibular hypofunction with aminoglycosides and measuring changes in the VOR and in a behavioral measure of vestibular noise, based on changes in the variance of eye velocity during fixation of a punctate target with the head stationary. In sum, these experiments will help answer longstanding and fundamental questions about how vestibular information is processed centrally, and this work will not only improve understanding of normal vestibular physiology but may also help elucidate the mechanisms responsible for the abnormal perceptual and eye movement responses that occur with disorders of the peripheral and central vestibular system.