Vestibular influences on spatial orientation

该项目的长期目标是了解大脑如何使用来自 前庭迷路来估计头部的空间方向和运动。 具体地说，这些实验将调查在线互动之间 来自半规管的旋转线索和重力惯性线索 由耳石器官传递。侧倾心理物理学和眼球运动 在恒河猴中测量，而旋转线索是由电 刺激后管壶腹神经。运河线索将在 隔离（头部处于不同的静态方向，眼睛处于不同的静态方向） 聚散角），并且还将与视觉（视动）和惯性线索相关联。倾斜 知觉将用来自主观的心理物理任务来测量。 视觉垂直（SVV），一种广泛用于评估前庭功能障碍患者的测试， 症状我们假设：1）半规管提供的旋转线索 有助于大脑对头部方向的估计，通过SVV的变化证明 耳道激活期间的反应，无法通过扭转眼的变化来解释 位置; 2）通过分离实际和估计的重力方向 相对于头部，垂直管道的电激活将引起异常的 线性加速度的估计，通过具有以下特征的眼球运动证明： 一种平移前庭眼反射这些实验将有助于阐明 来自半规管的旋转信息立即相互作用， 利用重力惯性线索产生头部感知估计的在线时尚 定向和反射前庭眼球运动。这些信息将有助于 更好地理解前庭神经病学的机制， 患有甲状腺和神经系统疾病的患者，包括 在大多数患者中占主导地位的临床表现的主诉（眩晕）。

The long-term goal of this project is to understand how the brain uses information from the vestibular labyrinth to estimate the spatial orientation and motion of the head. Specifically, these experiments will investigate the on-line interaction between rotational cues derived from the semicircular canals and gravito-inertial cues transduced by the otolith organs. Roll tilt psychophysics and eye movements will be measured in rhesus monkeys while rotational cues are acutely manipulated by electrical stimulation of the posterior canal ampullarynerves. Canal cues will be presented in isolation (with the head in different static orientations and with the eyes at different vergence angles) and will also be coupled to visual (optokinetic) and inertial cues. Tilt perception will be measured with a psychophysical task derived from the subjective visual vertical (SVV), a test which is widely used to evaluate patients with vestibular symptoms. We hypothesize: 1) that rotational cues provided by the semicircular canals contribute to the brain's estimate of head orientation, evidenced by a shift in SVV responses during canal activation that is not explainable by changes in torsional eye position; and 2) that by dissociating the actual and estimated direction of gravity relative to the head, electrical activation of the vertical canals will induce an aberrant estimate of linear acceleration, evidenced by eye movements with the characteristics of a translational vestibulo-ocular reflex. These experiments will help to elucidate how rotational informationderived from the semicircular canals interacts in an immediate, on-line fashion with gravito-inertial cues to produce perceptual estimates of head orientation and reflexivevestibular eye movements. This informationwill contribute to a better understanding of the mechanisms underlyingvestibular symptomatology in patients with labyrinthine and neurologic disorders, includingthe prominentperceptual complaints (vertigo) that dominate the clinical presentation in most patients.