Lubeck Astrid J A, Bos Jelte E, Stins John F
Research Institute MOVE, Faculty of Behavioural and Movement Sciences, VU University Amsterdam, De Boelelaan 1091, 1081 HV, Amsterdam, Netherlands.
TNO Perceptual and Cognitive Systems, TNO Soesterberg, Kampweg 5, 3769DE, Soesterberg, The Netherlands.
Atten Percept Psychophys. 2016 Nov;78(8):2612-2620. doi: 10.3758/s13414-016-1150-3.
Effects of visual roll-motion on postural sway and the subjective visual vertical (SVV) often is studied using mechanical devices, whereas electronic displays offer cheaper and more flexible alternatives. These devices typically emit and reflect light scattered by the edges of the screen, providing Earth-fixed cues of verticality. These cues may decrease the effects of rotating stimuli, a possibility that has not been studied explicitly before in one experimental design. We exposed 16 participants to a visual dot pattern, either stationary, or rotating in roll, that was or was not surrounded by a visible Earth-fixed reference frame. To eliminate unintended visual cues, the experiment was performed in complete darkness and participants wore neutral density goggles passing only 1% of light. Postural sway was measured using a force platform. SVV measurements were obtained from a visible rod. To monitor the participants, motion sickness severity was obtained with an 11-point rating scale. Results showed that the presence of an Earth-fixed frame significantly decreased the effect of the rotating pattern on postural sway and SVV deviations. Therefore, when studying subjective verticality related effects of visual stimuli, it is imperative that all visual Earth-fixed cues are not just minimized but completely eliminated. The observation that an Earth-fixed frame significantly decreased the effect of the rotating pattern on both postural sway and the SVV points towards a common neural origin, possibly involving a neural representation of verticality. Finally, we showed that an electronic screen can yield similar effect sizes as those taken from the literature using mechanical devices.
视觉滚动运动对姿势摆动和主观视觉垂直（SVV）的影响通常使用机械设备进行研究，而电子显示屏提供了更便宜且更灵活的替代方案。这些设备通常会发射并反射由屏幕边缘散射的光，提供固定于地球的垂直度线索。这些线索可能会降低旋转刺激的效果，这一可能性在之前的一个实验设计中尚未得到明确研究。我们让16名参与者观看一个视觉点图案，该图案要么静止，要么进行滚动旋转，且该图案周围有无可见的固定于地球的参考框架。为了消除意外的视觉线索，实验在完全黑暗的环境中进行，参与者佩戴仅能透过1%光线的中性密度护目镜。使用测力平台测量姿势摆动。通过一根可见的杆获取SVV测量值。为了监测参与者，使用11点量表获取晕动病严重程度。结果表明，固定于地球的框架的存在显著降低了旋转图案对姿势摆动和SVV偏差的影响。因此，在研究视觉刺激与主观垂直度相关的影响时，不仅要将所有固定于地球的视觉线索最小化，而且必须将其完全消除。固定于地球的框架显著降低了旋转图案对姿势摆动和SVV的影响这一观察结果指向一个共同的神经起源，可能涉及垂直度的神经表征。最后，我们表明电子屏幕可以产生与文献中使用机械设备得到的相似效应量。
