Vestibular influences on spatial orientation

这个项目的长期目标是了解大脑是如何使用来自 用于估计头部空间方向和运动的前庭迷路。 具体地说，这些实验将调查在线互动 来自半规管的旋转线索和重力惯性线索 通过耳石器官进行转换。翻滚倾斜心理物理学和眼球运动将 在恒河猴身上进行测量，而旋转线索是通过电信号敏锐地操纵的 刺激后管壶腹神经。运河提示将在 隔离(头部处于不同的静态方向，眼睛处于不同的位置 会聚角度)，并且还将与视觉(视动力)和惯性线索相关联。倾斜 知觉将通过由主观产生的心理物理任务来测量 视觉垂直(SVV)是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)半规管提供的旋转提示 有助于大脑对头部方向的估计，SVV的变化证明了这一点 管激活期间的反应不能用扭转眼的变化来解释 位置；以及2)通过分离实际和估计的重力方向 相对于头部，垂直通道的电激活会导致畸形 线性加速度的估计，由具有以下特征的眼球运动来证明 一种平移的前庭-眼睛反射。这些实验将有助于阐明 来自半规管的旋转信息在即时的， 利用重力-惯性线索在线方式产生对头部的感知估计 方向和反射性前庭眼球运动。这些信息将有助于 更好地理解前庭症状的发病机制 迷路和神经障碍患者，包括明显的知觉障碍 主诉(眩晕)在大多数患者的临床表现中占主导地位。

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.