MULTIDIMENSIONAL DYNAMICS OF THE VESTIBULO OCULAR REFLEX

描述：角和线性前庭眼反射（aVOR和 lVOR）可以以代偿性和空间定向为特征 机制等 代偿机制将眼睛移动到相反的位置 保持眼睛在空间中的稳定。 空间定向 机构倾向于使眼睛的转动或偏航轴与 重力惯性加速度（GIA） 补偿性IVOR已被 通过将其增益和相位特性与 一系列高度规则到高度不规则的耳石传入。 的算法 已经确定显示中央前庭系统如何联合收割机 耳石传入纤维的输出，以实现补偿性 lVOR的功能。 建议将建模方法扩展到 包括方向响应，例如眼睛的反向滚动和垂直 由于GIA绕鼻枕旋转导致的眼球倾斜， 耳间轴 齐次变换矩阵将用于建模 鼻枕部加速度引起的聚散 视觉和观看的影响 IVOR上的距离将被建模为聚散度的函数。 基于模型 实验提出了识别的参数的方向 一种能产生眼球反向滚动和垂直倾斜的系统。 使用 正弦离心、低速切向加速度将 识别IVOR补偿的高频特性，以及 定向机制和向心加速度将用于识别 低频特性。 时空会聚耳石 将研究前庭核中的相关单位，以确定是否 它们编码耳石传入行为的线性组合。 预计 这些神经元将分离平移和倾斜反应， 将具有补偿子系统和定向子系统的特征。 的 模型还将与速度的空间取向模型相结合 存储来预测定向和补偿行为， 离垂直轴旋转（OVAR）。 预计定向 IVOR的分量将调制速度存储的时间常数， 三个维度，并导致眼球反向滚动，垂直倾斜， 补偿机制将有助于振荡， 水平眼速度 收敛是否具有 补偿或定向系统将由其振幅确定， 相位特性 当IVOR-aVOR相互作用的模型已经被 建立，它将被用来预测响应的俯仰，而旋转 (PWR)用于居中和离轴旋转。 这种刺激激活了左室前壁， aVOR和聚散机制以类似的方式发生， 在圆周运动中。 这些研究应该有助于我们理解 lVOR在运动过程中促进清晰的视力，并帮助诊断疾病 与行走时的视觉稳定有关。

DESCRIPTION: The angular and linear vestibulo-ocular reflexes (aVOR and lVOR) can be characterized by compensatory and spatial orientation mechanisms. The compensatory mechanisms move the eyes to counter head movement so as to keep the eyes stable in space. Spatial orientation mechanisms tend to align ocular rotations or the yaw axis of the eye with the gravito-inertial acceleration (GIA). The compensatory IVOR has been modeled by relating its gain and phase characteristics to the behavior of a range of highly regular to highly irregular otolith afferents. An algorithm has been determined to show how the central vestibular system might combine the output of the otolith afferents so as to implement the compensatory function of the lVOR. It is proposed to extend the modeling approach to encompass orientation responses such as ocular counter-rolling and vertical ocular tilts due to rotations of the GIA about the naso-occipital and interaural axes. Homogeneous transformation matrices will be used to model vergence due to naso-occipital acceleration. Effects of vision and viewing distance on the lVOR will be modeled as a function of vergence. Model-based experiments are proposed to identify the parameters of the orientation system that generates ocular counter-rolling and vertical tilts. Using sinusoidal centrifugation, tangential acceleration at low velocities will identify the high frequency characteristics of the lVOR compensatory and orienting mechanisms and centripetal accelerations will be used to identify the low frequency characteristics. Spatio-temporal convergent (STC) otolith related units in the vestibular nuclei will be studied to determine whether they code a linear combination of otolith afferent behavior. It is expected that these neurons will segregate the translation and tilt responses and will have characteristics of the compensatory and orienting subsystems. The model will also be combined with the spatial orientation model of velocity storage to predict the orientation and compensatory behavior during off-vertical axis rotation (OVAR). It is expected that the orienting component of the lVOR will modulate the time constant of velocity storage in three dimensions and cause ocular counter-rolling, vertical tilt, and that the compensatory mechanisms will contribute to the oscillations in horizontal eye velocity. Whether convergence has properties of a compensatory or orienting system will be determined from its amplitude and phase characteristics. When the model of lVOR-aVOR interaction has been established, it will be used to predict the response to pitch while rotating (PWR) for centered and off-axis rotation. This stimulus activates the lVOR, aVOR, and vergence mechanisms in an analogous manner to that which occurs during circular locomotion. These studies should help us understand how the lVOR fosters clear vision during locomotion and help diagnose diseases associated with visual stabilization while walking.