CANAL, OTOLITH, AND VISUAL DETERMINANTS OF VOR ADAPTATION IN HUMAN BEINGS

自1970年以来，该实验室一直在研究前庭眼 反射（VOR）：其行为，基础神经生理学和适应性 可塑性 本建议的重点是进一步探讨 正常人前庭系统的运动学习能力 为了给锻炼计划提供更坚实的理论基础， 用于前庭障碍患者的康复。 前庭可塑性中的三个问题将在正常人中进行研究。 科目 项目A专注于耳石眼反应（OOR）， 与视神经和视觉刺激的相互作用及其可塑性。 最 自然的头部运动包含平移的分量， 旋转;前者必须由耳石检测。 的几种方法 将尝试评估OOR。 一种是检查L型眼球震颤： 由线性加速度引起的运动，但要小心控制 由于补偿性反应的大小， 平移取决于观看距离。 创造一个视觉- 前庭不匹配，通过放大镜，我们希望证明 耳石-眼可塑性 然后，不同的模式的线性和角 运动将被组合（使用偏心旋转），受试者将 看看在一个行为环境中学习的VOR可塑性是否可以转移到 到另 项目B解决VOR线性问题。 运河是非线性的， 一定的头部速度。 一侧完全被抑制，但VOR仍然 保持线性。 必须有一个补偿的、中心的（反）非线性 这应该在适应性控制之下。 这种能力将是 研究了 这一发现可能在康复方面有潜在的用途。 单侧前庭功能丧失的患者。 项目C研究了人们不断从一个转换到另一个的问题。 放大到另一个（双光眼镜，潜水员，低视力艾滋病）。 做 他们有两个VOR增益，他们可以来回切换吗？ 每一个拟议的实验都涉及到一个问题， VOR适配是特定于上下文的。 任何前庭康复计划 必须考虑在锻炼计划中获得的学习效果如何 转化为自然行为。

Since 1970, this laboratory has been investigating the vestibulo-ocular reflex (VOR): its behavior, underlying neurophysiology, and adaptive plasticity. The emphasis in this proposal is to explore further the capabilities for motor learning in the vestibular system of normal human beings in order to provide a firmer rationale for the exercise programs used to rehabilitate patients with vestibular disorders. Three problems in vestibular plasticity will be investigated in normal subjects. Project A concentrates on otolith-ocular responses (OOR), their interaction with canal and visual stimuli, and their plasticity. Most natural head motions contain components of translation as well as rotation; the former must be detected by the otoliths. Several methods to evaluate the OOR will be tried. One is to examine L-nystagmus: the eye movements that result from linear acceleration, but with careful control of the point of regard since the size of the compensatory responses to a translation depends upon viewing distance. By creating a visual- vestibular mismatch, as through magnifying goggles, we hope to demonstrate otolith-ocular plasticity. Then, different patterns of linear and angular motion will be combined (using eccentric rotation) and subjects tested to see if VOR plasticity learned in one behavioral context can be transferred to another. Project B addresses VOR linearity. The canals are nonlinear above a certain head speed. One side is completely inhibited, yet the VOR still remains linear. There must be a compensating, central (anti)nonlinearity that should be under adaptive control. This capability will be investigated. The findings may be of potential use in rehabilitation of patients with unilateral vestibular loss. Project C examines the problem of people who constantly switch from one magnification to another (bifocals, scuba divers, low-vision aids). Do they have two VOR gains and can they switch back and forth? Each of the proposed experiments bears on the issue of the degree to which VOR adaptation is context-specific. Any vestibular rehabilitation program must consider how well the learning acquired in an exercise program transfers to natural behavior.