MULTIDIMENSIONAL DYNAMIC OF THE VESTIBULO OCULAR REFLEX

描述(由申请人提供)：本项目的目标是模拟前庭系统如何在引起头部和身体的线性和角加速度的运动中帮助维持空间中的双眼注视。我们假设角型和线型前庭-眼反射(Avor和Ivor)可以通过激活代偿机制和空间定向机制来表征。在所提出的工作中，我们将通过结合版本和收敛来扩展这些想法，以研究双目视觉是否也可以根据补偿和定向理论来表征。一种使用旋转场线圈系统记录双眼三维运动的方法已经被开发出来。提出了一种新的数学方法，根据头部坐标中的收敛矩阵和版本矩阵来获得双眼的旋转。已经提出了利用这些矩阵和从头部坐标帧原点到每只眼睛的矢量来计算凝视凝视点的算法。初步研究表明，猴子可以被训练在视野中的不同位置注视目标，以校准每只眼睛。在第一个特定目标中，猴子将以0.5-4赫兹的速度沿着鼻枕和其他基轴直线加速，同时在距离头框原点不同角度和距离的空间中观察目标。这将考验依沃的补偿性能。在具体的目标2中，我们将利用旋转时平移(TWR)来确定低频线性加速度如何影响IVOR的双眼注视特性，我们假设这将由双眼定位机制产生，该机构将倾向于将双眼注视与重力惯性净加速度(GIA)对齐。在特定的目标3中，猴子将使用沿重力加速度轴的线性加速度进行测试。我们假设这将在中频段诱导没有通常伴随的定向反应的代偿性眼动反应。我们预计补偿性反应将在空间中保持固定的凝视点，而方位反应将倾向于将眼睛或眼球速度与所产生的GIA对准。我们还将模拟特定目标4中描述的三维补偿和定向会聚以及版本交互。当研究完成时，我们将有一个关于前庭系统如何在运动时有助于维持双眼凝视稳定性的定量模型。

DESCRIPTION (provided by applicant): The objective of this project is model how the vestibular system contributes to maintaining binocular fixation in space during motions that induce linear and angular accelerations of the head and body. We have hypothesized that the angular and linear vestibulo-ocular reflexes (aVOR and IVOR) can be characterized through the activation of compensatory and spatial orientation mechanisms. In the proposed work, we will extend these ideas by combining version and vergence to study whether binocular viewing can also be characterized in terms of the compensatory and orienting theory. A methodology for recording binocular eye movements in three dimensions using a rotating field coil system has been developed. A new mathematical methodology has been proposed to obtain the rotation of the two eyes in terms of convergence and version matrices in head coordinates. Algorithms have been proposed that will utilize these matrices and a vector from the head coordinate frame origin to each eye to compute gaze fixation points. Preliminary studies indicate monkeys can be trained to fixate targets at various positions in the visual field to calibrate each eye. In the first specific aim, monkeys will be linearly accelerated along naso-occipital and other cardinal axes at 0.5-4 Hz, while viewing targets in space at various angles and distances from the origin of the head frame. This will test the compensatory properties of the IVOR. In specific aim 2, we will utilize translation while rotating (TWR) to determine how low frequency linear acceleration affects the binocular gaze characteristics of the IVOR, which we hypothesize will be generated by the binocular orientation mechanisms that will tend to align binocular fixation with the net gravito-inertial acceleration (GIA). In specific aim 3, monkeys will be tested using linear acceleration along the axis of the gravitational acceleration. We hypothesize that this will induce compensatory oculomotor responses without the usual concomitant orientation responses at midband frequencies. We expect that compensatory response will maintain fixed gaze points in space while orientation responses will tend to align the eyes or eye velocity with the resultant GIA. We will also model the three-dimensional compensatory and orientation convergence and version interaction as described in specific aim 4. When the study is completed, we will have a quantitative model of how the vestibular system contributes to maintenance of binocular gaze stability while moving.