SENSORIMOTOR INTEGRATION IN HUMAN POSTURAL CONTROL

描述：(逐字摘自申请表)本项目的长期目标 是理解感觉运动整合本体感觉、视觉和 前庭信息有助于人类姿势的稳定。一个完整的 理解姿势控制需要了解平衡是如何进行的 当感觉整合过程受到条件的挑战时保持 限制和/或改变可用的感觉线索，以及改变的身体 动力学。这一提议的主要假设是，这种整合 过程受到积极的监管。来展示和描述这一活动 规则，研究的重点是与以下相关的姿势反应 突然限制或恢复方向提示或突然改变的过渡 身体动力学。 拟议的实验是由最近获得的数据推动的 演示特有的瞬时摆动车身摆动跟随 突然恢复准确定位提示的环境转换。 模拟研究表明，观察到的振荡行为是由 产生过多的矫正腿部肌肉扭矩。快速修复 正常的、非振荡的身体摆动表明感觉运动调节 存在能够快速将校正扭矩降低到 适当的水平。此外，初步结果表明，这 双侧前庭缺失的受试者存在调节机制 功能，但这一机制受到损害，可能使前庭 损失的对象比正常人更容易受到以下不稳定因素的影响 环境转变改变了可用的感觉定向线索。 拟议工作有两个具体目标。第一个目标是 描述神经机制的特性，这些神经机制主动调节 人体姿态控制系统实现平衡的最优动态控制 不断变化的环境。二是刻画了系统的非线性特性 前庭对姿势控制的贡献，并理解这是如何 非线性行为对感觉-运动整合过程有贡献。这个 拟议的研究依赖于基于模型的方法来解释和预测 姿势行为由感觉运动调节机制决定 感官整合的过程。 异常涉及感觉运动整合的主动调节和 增益控制可能是不稳定和跌落的一个未被认识的来源。更好的 对这些积极监管过程的理解可能会导致新的 康复方法和改进的临床平衡功能测试。

DESCRIPTION: (verbatim from the application) The long-term goal of this project is to understand how sensorimotor integration of proprioceptive, visual, and vestibular information contributes to postural stability in humans. A complete understanding of postural control requires knowledge of how balance is maintained when the sensory integration process is challenged by conditions that limit and/or alter the available sensory cues, and that alter body dynamics. The principal hypothesis of this proposal is that this integration process is actively regulated. To demonstrate and characterize this active regulation, the focus of the research is on postural responses associated with transitions which suddenly limit or restore orientation cues or suddenly change body dynamics. The proposed experiments are motivated by recently acquired data that demonstrate characteristic transient oscillatory body sway following environmental transitions which suddenly restore accurate orientation cues. Modeling studies suggest that the observed oscillatory behavior is caused by an over generation of corrective leg muscle torque. The rapid restoration of normal, non-oscillatory body sway suggests that a sensorimotor regulatory mechanism exists that is able to quickly reduce corrective torque to an appropriate level. Additionally, preliminary results indicate that this regulatory mechanism is present in subjects with bilaterally absent vestibular function, but that this mechanism is compromised, possibly making vestibular loss subjects more susceptible than normals to instability following environmental transitions which alter the available sensory orientation cues. There are two specific aims of the proposed work. The first aim is to characterize the properties of neural mechanisms that actively regulate the human postural control system to achieve optimal dynamic control of balance in changing environments. The second is to characterize nonlinear properties of the vestibular contribution to postural control, and to understand how this nonlinear behavior contributes to the sensorimotor integration process. The proposed research relies on a model-based approach to explain and predict postural behavior determined by sensorimotor regulatory mechanisms involved in the sensory integration process. Abnormalities involving the active regulation of sensorimotor integration and gain control may be an unrecognized source of instability and falls. A better understanding of these active regulatory processes may lead to new rehabilitation methods and improved clinical balance function tests.