Field of view and base of support width influence postural responses to visual stimuli during quiet stance
Field of view and base of support width influence postural responses to visual stimuli during quiet stance
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DOI：
10.1016/j.gaitpost.2005.12.013
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发表时间：
2007-01-01
期刊：
影响因子：
2.4
通讯作者：
Keshner, Emily A.
中科院分区：
文献类型：
--
作者：
Streepey, Jefferson W.;Kenyon, Robert V.;Keshner, Emily A.
我们探讨了支持基底（BOS）和视野（FOV）变窄时视野运动的不稳定效应。使用沉浸式虚拟环境（场景）实现视野运动，该虚拟环境随着头部运动（自然运动）逼真地移动，并在前后方向上以0.1 Hz正弦平移（增强运动）。自然运动以立体方式呈现，而增强运动以立体和非立体方式呈现。受试者在宽（水平和垂直方向90度和55度）和窄（两个方向均为25度）FOV条件下观察场景运动，同时站立平足（100% BOS）和两个街区（45%和35% BOS）。确定头部和全身质心（COM）和踝关节角度均方根（RMS），以及头部、全身和小腿COM FFT。在自然运动过程中，主要影响出现在头部RMS中，与窄FOV相比，35% BOS和宽FOV下的RMS显著更小。然而，增强运动的主要效应出现在头部和全身COM的功效分析中，与100%BOS相比，35%BOS的宽FOV显著增加。统计分析表明BOS对头部和全身RMS的深度感知有影响;然而，事后比较显示立体声和非立体声增强运动之间没有显著差异。我们的结论是，减少BOS增加了对周边视觉信息的依赖，以稳定头部在空间中，即使增强的视觉运动促进姿势不稳定。(C)2006 Elsevier B.V.保留所有权利。
We explored the destabilizing effect of visual field motion as the base of support (BOS) and the field of view (FOV) were narrowed. Visual field motion was achieved using an immersive virtual environment (scene) that moved realistically with head motion (natural motion) and translated sinusoidally at 0.1 Hz in the fore-aft direction (augmented motion). Natural motion was presented in stereo while augmented motion was presented in both stereo and non-stereo. Subjects viewed scene motion under wide (90 degrees and 55 degrees in the horizontal and vertical directions) and narrow (25 degrees in both directions) FOV conditions while standing flatfooted (100% BOS) and on two blocks (45% and 35% BOS). Head and whole body center of mass (COM) and ankle angle root mean square (RMS) were determined as were head, whole body, and shank COM FFTs. During natural motion, the primary effect emerged in the head RMS which was significantly smaller with a 35% BOS and the wide FOV compared to the narrow FOV. However, the primary effect of augmented motion emerged in the power analysis of head and whole body COM which significantly increased with the wide FOV for a 35% BOS compared to 100% BOS. Statistical analysis indicated an effect of BOS on depth perception for head and whole body RMS; however, post hoc comparisons revealed no significant differences between stereo and non-stereo augmented motion. We conclude that reducing the BOS increased reliance on peripheral visual information to stabilize the head in space even when the augmented visual motion promoted postural instability. (C) 2006 Elsevier B.V. All rights reserved.