Adaptive Gaze Strategies for Locomotion with Constrictred Visual Field
Adaptive Gaze Strategies for Locomotion with Constrictred Visual Field
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DOI：
10.3389/fnhum.2017.00387
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发表时间：
2017-07-27
影响因子：
2.9
通讯作者：
Safran, Avinoam B.
中科院分区：
文献类型：
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作者：
Authie, Colas N.;Berthoz, Alain;Safran, Avinoam B.
在色素性视网膜炎（RP）中，周围视野的丧失是运动过程中视觉运动协调困难的主要原因。本研究的目的是准确评估周边视野丧失对运动凝视策略的影响，并确定补偿机制。九名RP受试者中心视野限制在10-25。在直径上，9名健康的受试者被要求沿着三个方向之一行走——笔直地朝着一个视觉目标，向左和向右穿过门框，路上有或没有障碍物。通过运动捕捉记录全身运动，利用眼动仪重建空间凝视方向。在RP受试者中发现了凝视策略的变化，包括行走前的广泛探索，频繁的注视地面（即使知道没有障碍物），门的边缘，主要是最近的一个，障碍物边缘/角落，以及在接近门时交替注视门的边缘。这与更频繁，有时更大的快速眼球运动，更大的运动和头部前倾有关。尽管存在视觉障碍，但两组之间的轨迹几何形状是相同的，rp的行走速度略有下降。这些发现确定了感觉-运动协调的适应性变化，以确保对周围环境的视觉感知，检测空间配置的变化，收集自我运动的信息，更新姿势参考框架，并更新自我中心与环境物体的距离。它们对于优化康复程序的设计至关重要。
In retinitis pigmentosa (RP), loss of peripheral visual field accounts for most difficulties encountered in visuo-motor coordination during locomotion. The purpose of this study was to accurately assess the impact of peripheral visual field loss on gaze strategies during locomotion, and identify compensatory mechanisms. Nine RP subjects presenting a central visual field limited to 10-25. in diameter, and nine healthy subjects were asked to walk in one of three directions-straight ahead to a visual target, leftward and rightward through a door frame, with or without obstacle on the way. Whole body kinematics were recorded by motion capture, and gaze direction in space was reconstructed using an eye-tracker. Changes in gaze strategies were identified in RP subjects, including extensive exploration prior to walking, frequent fixations of the ground (even knowing no obstacle was present), of door edges, essentially of the proximal one, of obstacle edge/corner, and alternating door edges fixations when approaching the door. This was associated with more frequent, sometimes larger rapid-eye-movements, larger movements, and forward tilting of the head. Despite the visual handicap, the trajectory geometry was identical between groups, with a small decrease in walking speed in RPs. These findings identify the adaptive changes in sensory-motor coordination, in order to ensure visual awareness of the surrounding, detect changes in spatial configuration, collect information for self-motion, update the postural reference frame, and update egocentric distances to environmental objects. They are of crucial importance for the design of optimized rehabilitation procedures.