Automatic control of postural sway by visual motion parallax
Automatic control of postural sway by visual motion parallax
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DOI：
10.1007/bf02450322
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发表时间：
1997-02-01
影响因子：
2
通讯作者：
Buckwell, D
中科院分区：
文献类型：
--
作者：
Bronstein, AM;Buckwell, D
本研究的目的是确定是否视觉运动视差参与控制的姿势摇摆。采用光电头动记录法和测力板姿势描记法对10名正常人的身体摇摆进行了测量。受试者在三种不同的条件下观看视觉显示（“背景”），该视觉显示沿y（水平）轴沿着移动（2 a）：（1）直接固定背景，（2）固定前景中的固定窗框，以及（3）在前景中存在窗口的情况下固定背景（“通过窗口”）。在响应背景固定，受试者在相同的方向摆动的刺激运动，但在前景（窗口）固定，他们在相反的方向摆动。在两种条件下，在测力平台上观察到的早期力发生在约250 ms处。结果表明，运动视差产生姿势反应。这些视差诱发的姿势反应的方向--与迄今为止报道的其他视觉诱发的姿势反应相反--适合在自然情况下稳定姿势。研究结果表明，运动视差是自我运动信息的重要来源，这些信息参与了自动姿势控制的过程。在“通过窗户注视”的条件下，不模仿身体摇摆引起的视觉条件，没有一致的姿势反应。这意味着由视觉运动引起的姿势反应不是对视动刺激的刚性反应，而是对视觉刺激信号自我运动的反应。
The purpose of this study was to establish whether visual motion parallax participates in the control of postural sway. Body sway was measured in ten normal subjects by photoelectric recordings of head movements and by force-plate posturography. Subjects viewed a visual display (''background''), which briefly moved (2 a) along the y (horizontal) axis, under three different conditions: (1) direct fixation of the background, (2) fixation of a stationary window frame in the foreground, and (3) fixation of the background in the presence of the window in the foreground (''through the window''). In response to background fixation, subjects swayed in the same direction as stimulus motion, but during foreground (window) fixation they swayed in the opposite direction. The earlier forces observed on the force plat form occurred at circa 250 ms in both conditions. The results show that motion parallax generates postural responses. The direction of these parallax-evoked postural responses - opposite to other visually evoked postural responses reported so far - is appropriate for stabilizating posture in natural circumstances. The findings show that motion parallax is an important source of self-motion information and that this information participates in the process of automatic postural control. In the ''fixating through the window'' condition, which does not mimic visual conditions induced by body sway, no consistent postural responses were elicited. This implies that postural reactions elicited by visual motion are not rigid responses to optokinetic stimulation but responses to visual stimuli signalling self-motion.