Measuring and Isolating Imprecision in Vestibular Perception and Action

描述（由申请人提供）：精确的运动控制和感知对生存至关重要-无论是在崎岖地形上奔跑的猎物还是在航空母舰上降落的飞行员。行为的精确度取决于许多层面的精确度——例如，感觉转导、运动单元和中枢神经系统——至于哪个层面限制了整体的精确度，还存在一些悬而未决的问题。作为基本的例子，我们不知道大多数前庭反射（VOR）不精确是起源于外周神经系统、中枢神经系统还是动眼神经系统。同样地，我们也不知道大部分的知觉不精确是来自外围神经还是中枢神经系统。这项研究的长期总体目标是了解精确度在感觉、行为、病理、临床诊断和神经处理中的作用。前庭系统的相对简单使其成为研究大脑如何处理噪音的基本原理的绝佳模型，这可能更广泛地适用于其他感觉系统。这项工作的短期目标是了解前庭感觉运动反射和知觉的精度，使用新的技术来测量和隔离不精确的来源。例如，如果能够分离出不精确的来源，就可以加强诊断特定疾病的临床试验的敏感性。为实现这一目标，我们提出以下具体目标。目的1：通过同时分析人类的VOR和感知精度来研究感觉、运动和感知噪声。为了确定VOR和感知阈值对共享噪声源的依赖程度，我们建议使用阈值水平刺激同时测量感知和VOR反应，并量化每个试验的共变。我们假设一个共同的，可能是外围感觉噪声源是偏航旋转和耳间翻译的知觉和动眼力反应的基础。目标2：我们将通过利用平移VOR的独特特征来分离感觉和运动精度-响应的灵敏度可以通过固定距离调节-允许通路的感觉和运动成分有效解耦。我们将测量对重复刺激反应的试验对试验的VOR变异性，同时假设依赖于感觉不精确的VOR变异性将随VOR敏感性而缩放。我们假设感觉噪声主导平移VOR变异性。

DESCRIPTION (provided by applicant): Precision in motion control and perception is critical to survival - whether prey running over rough terrain or a pilot landing on an aircraft carrier. Behavioral precision depends on precision at many levels - e.g. sensory transduction, motor units, and the central nervous system - and there are open questions about which level(s) limit overall precision. As fundamental examples, we don't know whether the majority of vestibuloocular reflex (VOR) imprecision originates in the periphery, the CNS, or the oculomotor system. Similarly, we do not know whether the majority of perceptual imprecision originates in the periphery or CNS. The long-term general goal of this research is to understand the role of precision in sensation, behavior, pathology, clinical diagnosis and neural processing. The relative simplicity of the vestibular system makes it an excellent model to study the basic principles of how the brain processes noise, which may be more broadly applicable to other sensory systems. The short-term goal of this work is to understand precision in vestibular sensorimotor reflexes and perception using novel techniques to measure and isolate sources of imprecision. For example, the sensitivity of clinical tests at diagnosing particular disorders coul be strengthened if sources of imprecision could be isolated. To achieve this goal, we propose the following specific aims. Aim 1: Study sensory, motor and perceptual noise by simultaneously assaying VOR and perceptual precision in humans. To determine the extent to which the VOR and perceptual thresholds depend on a shared noise source, we propose to measure perceptual and VOR responses simultaneously using threshold-level stimuli, and quantify trial-by-trial co-variation. We hypothesize that a shared, presumably peripheral sensory noise source underlies both perceptual and oculomotor responses for yaw rotation and inter-aural translation. Aim 2: We will separate sensory and motor precision by exploiting a unique characteristic of the translational VOR - that the sensitivity of the response can be modulated by fixation distance - allowing the effective decoupling of the sensory and motor components of the pathway. We will measure trial-to-trial VOR variability in response to repeated stimuli, while presuming that VOR variability dependent on sensory imprecision will scale with VOR sensitivity. We hypothesize that sensory noise dominates translational VOR variability.