Visual Control of Locomotion

描述（由申请人提供）：该项目的长期目标是开发一个在复杂动态环境中视觉控制运动行为的模型。首先，什么是运动的行为动力学--如何确定转向、避障、拦截和逃跑的运动路径？第二，运动的控制法则是什么--视觉和本体感受信息是如何用来调节这些基本的运动行为的？在以前的研究中，我们研究了基本的运动行为（a）转向一个固定的目标，（B）避免固定的障碍物，（c）拦截一个移动的目标，（d）避免移动的障碍物，和（e）逃避移动的追求者。我们分别测试了前四种行为，并开发了一个成功预测人类运动路径的动力学模型。 该研究的具体目的是调查这些成分是如何在更复杂的环境中整合的，以及用于指导它们的感知策略。使用虚拟现实技术，头戴式显示器将呈现给自由行走的观察者，测量运动路径，并对由此产生的行为进行正式建模。建议进行四项研究：（1）转向和避障的整合研究转向固定或移动目标如何与避免固定或移动障碍物整合。(2)转向和避障的控制律追求光流、自我中心方向和头部/身体对准的相互作用，以引导步行到固定的目标和障碍物。(3)规划或在线控制研究是否基于关于目标和障碍物的当前信息来控制转向，或者是否预先规划路径。(4)交互式环境中的转向研究了参与者和使用模型编程的模拟代理之间的动态交互，例如两个人试图通过对方或一个人试图穿过人群。 研究结果将有助于对运动的视觉控制的基础知识，并为疾病和衰老中的视觉运动缺陷和运动问题的临床研究提供基础。一个工作模型将能够预测日常环境中的运动行为，模拟特定的缺陷，预测移动风险，并测试潜在的适应能力。

DESCRIPTION (provided by applicant): The long-term objective of this project is to develop a model of visually controlled locomotor behavior in complex, dynamic environments. First, what are the behavioral dynamics of locomotion - how are paths of locomotion determined for steering, obstacle avoidance, interception, and escape? Second, what are the control laws for locomotion - how is visual and proprioceptive information used to regulate these basic locomotor behaviors? In previous research, we investigated the basic locomotor behaviors of (a) steering to a stationary target, (b) avoiding stationary obstacles, (c) intercepting a moving target, (d) avoiding moving obstacles, and (e) escaping moving pursuers. We tested the first four behaviors individually and developed a dynamical model that successfully predicts human locomotor paths. The specific aim of the proposed research is to investigate how these components are integrated in more complex environments, and the perceptual strategies used to guide them. Using virtual reality techniques, head-mounted displays will be presented to a freely walking observer, the path of locomotion will be measured, and the resulting behavior formally modeled. Four studies are proposed: (1) Integration of steering and obstacle avoidance examines how steering to a stationary or moving target is integrated with avoidance of stationary or moving obstacles. (2) Control laws for steering and obstacle avoidance pursues interactions of optic flow, egocentric direction, and head/body alignment to guide walking to stationary targets and obstacles. (3) Planning or on-line control investigates whether steering is controlled on the basis of current information about the target and obstacles, or whether paths are planned in advance. (4) Steering in interactive environments investigates dynamic interactions between a participant and simulated agents that are programmed using the model, such as two people trying to pass each other or a person trying to walk through a crowd. The results will contribute to basic knowledge about the visual control of locomotion and provide a foundation for clinical research on visual-motor deficits and mobility problems in disease and aging. A working model would enable predictions of locomotor behavior in everyday environments, simulations of specific deficits, forecasting of mobility risks, and testing of potential accommodations.