Department of Human Sciences, Tokyo Metropolitan University, Tokyo, Japan.
Department of Health Promotion Sciences, Tokyo Metropolitan University, Tokyo, Japan.
PLoS One. 2021 Sep 10;16(9):e0257212. doi: 10.1371/journal.pone.0257212. eCollection 2021.
Postural control in quiet standing is often explained by a reflexive response to optical flow, the apparent motion of environmental objects in a visual scene. However, moving room experiments show that even small-amplitude body sway can evoke odd sensations or motion sickness, indicating that a consciousness factor may also be involved. Studies targeting perception of self-motion, vection, typically use rapid visual stimuli moving in a single direction to maintain a constant feeling of vection, and there are few studies of vection using low-speed sinusoidal visual stimuli similar to human pendular movement. In the present study we searched for changes in postural control during periods of vection during quiet standing. Participants (N = 19, age = 20.4 ±1.1 years) were shown dynamic visual stimuli in the form of sinusoidally expanding and contracting random dots, and the stimuli speed and visual field were manipulated. Posture was continually evaluated using Center of Pressure (CoP) measurements. Participants were also asked to report feelings of vection, both by pressing a button during the trial and through an overall rating at the end of each trial. Using repeated-measures ANOVA, we assessed changes in the CoP and vection variables between experimental conditions, as well as possible interactions between the variables. The results show that postural reaction and vection were both affected by the visual stimuli and varied with speed. The peripheral visual field was found to couple to stronger feeling of vection and better quality of postural control. However, no significant relationship between postural control and vection, nor evidence of vection interaction to the relationship between optical flow and postural control, was found. Based on our results we conclude that for postural stability during quiet standing, visual cues dominate over any potential consciousness factor arising due to vection.
在安静站立时，姿势控制通常可以通过对光流的反射性反应来解释，即视觉场景中环境物体的表观运动。然而，移动房间实验表明，即使是小幅度的身体摆动也会引起奇怪的感觉或晕动病，这表明意识因素也可能参与其中。针对自我运动知觉、运动错觉的研究，通常使用沿单一方向移动的快速视觉刺激来保持恒定的运动错觉感觉，而使用类似于人体摆动的低速正弦视觉刺激来研究运动错觉的研究较少。在本研究中，我们在安静站立时的运动错觉期间搜索姿势控制的变化。参与者（N=19，年龄=20.4±1.1 岁）被展示了正弦形扩展和收缩随机点的动态视觉刺激，并且刺激速度和视野被操纵。姿势通过压力中心（CoP）测量值不断进行评估。参与者还被要求在试验期间通过按钮报告运动错觉的感觉，并在每次试验结束时进行整体评分。使用重复测量方差分析，我们评估了实验条件下 CoP 和运动错觉变量之间的变化，以及变量之间可能的相互作用。结果表明，姿势反应和运动错觉都受到视觉刺激的影响，并随速度而变化。发现外围视野与更强的运动错觉感觉和更好的姿势控制质量相关。然而，没有发现姿势控制和运动错觉之间存在显著关系，也没有证据表明运动错觉与光流和姿势控制之间的关系相互作用。根据我们的结果，我们得出结论，对于安静站立时的姿势稳定性，视觉线索优于由于运动错觉而产生的任何潜在意识因素。
