Mitsudo Hiroyuki, Ono Hiroshi
ATR Human Information Science Laboratories, 2-2-2 Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-0288, Japan.
Perception. 2007;36(1):125-34. doi: 10.1068/p5562.
Two psychophysical experiments were conducted to investigate the mechanism that generates stable depth structure from retinal motion combined with extraretinal signals from pursuit eye movements. Stimuli consisted of random dots that moved horizontally in one direction (ie stimuli had common motion on the retina), but at different speeds between adjacent rows. The stimuli were presented with different speeds of pursuit eye movements whose direction was opposite to that of the common retinal motion. Experiment 1 showed that the rows moving faster on the retina appeared closer when viewed without eye movements; however, they appeared farther when pursuit speed exceeded the speed of common retinal motion. The 'transition' speed of the pursuit eye movement was slightly, but consistently, larger than the speed of common retinal motion. Experiment 2 showed that parallax thresholds for perceiving relative motion between adjacent rows were minimum at the transition speed found in experiment 1. These results suggest that the visual system calculates head-centric velocity, by adding retinal velocity and pursuit velocity, to obtain a stable depth structure.
进行了两项心理物理学实验，以研究从视网膜运动与追踪眼球运动的视网膜外信号相结合产生稳定深度结构的机制。刺激由在一个方向上水平移动的随机点组成（即刺激在视网膜上有共同运动），但相邻行之间的速度不同。刺激以不同速度的追踪眼球运动呈现，其方向与视网膜共同运动的方向相反。实验1表明，在没有眼球运动的情况下观察时，视网膜上移动较快的行看起来更近；然而，当追踪速度超过视网膜共同运动速度时，它们看起来更远。追踪眼球运动的“转换”速度略高于但始终高于视网膜共同运动速度。实验2表明，在实验1中发现的转换速度下，感知相邻行之间相对运动的视差阈值最小。这些结果表明，视觉系统通过将视网膜速度和追踪速度相加来计算以头部为中心的速度，以获得稳定的深度结构。
