Sensorimotor Integration in Human Postural Control

描述（由申请人提供）：T 这个项目的长期目标是了解感觉运动整合如何有助于人类的姿势稳定性。要全面了解姿势控制，需要了解中枢神经系统（CNS）如何整合来自多个感官来源的身体定向信息，以响应不断变化的环境条件，并产生适当的平衡校正，以及生物力学如何影响使用感官信息进行姿势控制。这个建议的中心假设是，中枢神经系统积极调节感觉整合，以实现最佳的动态控制平衡的环境中，改变可用的感觉取向信息，并在生物力学因素约束身体运动和改变稳定性限制的条件。 拟议的工作有三个具体目标。第一个目的是确定被动的，生物力学相关的和主动的，神经介导的贡献，产生平衡校正所需的平衡控制在矢状面。被动和主动机制将根据连续扰动平衡引起的身体摇摆反应的时间来区分。姿势控制系统也将受到挑战，人为地延迟感官定向信息的到达，以确定受试者如何补偿延迟的感官反馈。第二个目的是确定姿势控制系统整合多个感官定向信息源的能力。该假设是，感觉整合是通过加权组合的感觉线索，权重因子的变化作为一个功能的环境和生物力学条件，和权重因子的选择是由一个最优控制策略。第三个目的是表征感觉运动整合策略用于控制身体摇摆在额面，并确定如何生物力学的限制，由于在立场宽度的变化影响的感觉运动整合过程。 这项研究依赖于一种基于模型的方法来解释和预测各种环境和实验条件下的姿势行为。将广泛使用工程学科为系统识别开发的方法。 涉及感觉运动整合的主动调节的ababduction可能是不稳定和福尔斯的一个未被认识的来源。更好地了解这些主动调节过程可能会导致新的康复方法和新的临床平衡功能测试。

DESCRIPTION (provided by applicant): T The long-term objective of this project is to understand how sensorimotor integration contributes to postural stability in humans. A complete understanding of postural control requires knowledge of how the central nervous system (CNS) integrates body-orientation information from multiple sensory sources to generate appropriate balance corrections in response to changing environmental conditions and how biomechanics influence the use of sensory information for postural control. The central hypothesis of this proposal is that the CNS actively regulates sensory integration to achieve optimal dynamic control of balance in environments that alter the available sensory-orientation information and in conditions where biomechanical factors constrain body motion and alter stability limits. The proposed work has three specific aims. The first aim is to identify the passive, biomechanically related and active, neurally-mediated contributions to the generation of balance corrections required for balance control in the sagittal plane. Passive and active mechanisms will be distinguished from one another based on the timing of body-sway responses evoked by continuous perturbations to balance. The postural control system will also be challenged by artificially delaying the arrival of sensory-orientation information to determine how subjects compensate for delayed sensory feedback. The second aim is to determine the ability of the postural control system to integrate multiple sources of sensory-orientation information. The hypothesis is that sensory integration is achieved by a weighted combination of sensory cues, the weighting factors change as a function of environmental and biomechanical conditions, and the selection of weighting factors is determined by an optimal-control strategy. The third aim is to characterize the sensorimotor integration strategies used for the control of body sway in the frontal plane and to determine how biomechanical constraints due to changes in stance width influence the sensorimotor-integration process. The proposed research relies on a model-based approach to explain and to predict postural behavior in a variety of environments and experimental conditions. Methodology developed in engineering disciplines for system identification will be used extensively. Abnormalities involving the active regulation of sensorimotor integration may be an unrecognized source of instability and falls. A better understanding of these active regulatory processes may lead to new rehabilitative methods and new clinical balance-function tests.