Minimizing Instability with Dynamic Visual Inputs

这个项目的长期目标是了解如何平衡和步态障碍可以帮助使用 动态视觉环境，以促进运动和站立姿势控制期间的感觉运动再学习。 当前庭输入变得不可靠时，无论是由于听觉损失还是功能障碍，个体必须学会 依靠视觉和本体感受通路对姿势方向的变化产生适当的反应 或平衡。尝试通过练习姿势和有目的的活动来产生感觉再学习， 静态环境并没有被证明是一种完全成功的干预，这可能是因为受控输入确实是一种有效的干预。 不对姿势系统的功能性提出必要的要求。个人可能会固定在一个 响应模式，无法匹配环境中遇到的干扰范围。我们提出 研究动态视觉环境下运动过程中姿势反应和空间定向的变化， 环境中的正常受试者和患者的双侧谷胱甘肽损失。我们假设个人- 前庭损失成为固定在一个战略的补偿，并不能补偿波动 动态环境的要求。我们将研究是否提供使用视觉信息的策略， 帮助这些个体补偿不稳定。受试者将在安静站立时接受测试， 在跑步机上行走，同时我们操纵动态虚拟环境的速度或上下文对比。 将测量节段偏移和压力中心，并使用重复测量ANOVA进行分析， 确定姿势组织和定向是否受外周场的特定参数的影响， 风景最不稳定的参数将应用于训练计划，受试者将 指示专注于远处的目标或内部反馈，以确定是否在动态视觉中的主动表现 环境增加了具有谷胱甘肽损失的个体的反应库。最后，我们将评估 在动态视觉环境中的训练存在功能遗留。受试者将进行模拟 物理世界的任务，他们必须检索和放置对象，而世界在他们周围移动， 障碍物出现在他们的道路上。这些研究的结果将提供对视觉动力学的深入了解- 前庭的相互作用，并确定具体的定量协议，治疗干预与平衡 紊乱

The long-term goal of this project is to understand how balance and gait disorders can be helped by using dynamic visual environments to facilitate sensorimotor relearning during locomotion and stance postural control. When vestibular inputs become unreliable, either from labyrinthine loss or dysfunction, individuals must learn to rely upon visual and proprioceptive pathways to produce appropriate responses for changes in postural orientation or equilibrium. Attempts to produce sensory relearning through practicing postural and purposeful activities in static environments have not proved to be a fully successful intervention, possibly because the controlled inputs do not place the necessary demands on the functionality of the postural system. Individuals may become fixed on one pattem of response and be unable to match the range of disturbances encountered in the environment. We propose to study changes in postural responses and spatial orientation during locomotion within a dynamic visual environment in normal subjects and in patients with bilateral labyrinthine loss. We hypothesize that individuals _ with vestibular loss become fixed on one strategy of compensation and can not compensate for the fluctuating demands of a dynamic environment. We will examine whether providing strategies for using visual information assists these individuals in compensating for destabilization. Subjects will be tested during quiet stance and walking on a treadmill while we manipulate the velocity or contextual contrast of a dynamic virtual environment. Segmental excursions and center of pressure will be measured and analyzed with repeated measures ANOVAs to determine if postural organization and orientation is influenced by specific parameters of the peripheral field of view. The parameters that emerge as most destabilizing will be applied in a training program where subjects will be instructed to focus on a distant target or on internal feedback to determine if active performance in a dynamic visual environment increases the response repertoire of individuals with labyrinthine loss. Finally, we will assess whether there is functional carryover from training within a dynamic visual environment. Subjects will perform a simulated physical world task in which they must retrieve and place an object while the world moves around them and obstacles appear in their path. Results from these studies will provide insight into the dynamics of the visual- vestibular interaction and identify specific quantitative protocols for therapeutic interventions with balance disorders.