Kim Sung-Ho, Feldman Jacob, Singh Manish
Department of Psychology and Center for Cognitive Science, Rutgers University, New Brunswick, NJ, USA.
Atten Percept Psychophys. 2012 Feb;74(2):350-64. doi: 10.3758/s13414-011-0237-0.
We investigated whether amodal completion can bias apparent motion (AM) to deviate from its default straight path toward a longer curved path, which would violate the well-established principle that AM follows the shortest possible path. Observers viewed motion sequences of two alternating rectangular tokens positioned at the ends of a semicircular occluder, with varying interstimulus intervals (ISIs; 100-500 ms). At short ISIs, observers tended to report simple straight-path motion-that is, outside the occluder. But at long ISIs, they became increasingly likely to report a curved-path motion behind the occluder. This tendency toward reporting curved-path motion was influenced by the shape of tokens, display orientation, the gap between tokens and the occluder, and binocular depth cues. Our results suggest that the visual system tends to minimize unexplained absence of a moving object, as well as its path length, such that AM deviates from the shortest path when amodal integration of motion trajectory behind the curved occluder can account for the objective invisibility of the object during the ISI.
我们研究了无模态完成是否会使表观运动（AM）偏离其默认的直线路径，而偏向更长的曲线路径，这将违背已确立的原则，即AM遵循尽可能短的路径。观察者观看位于半圆形遮挡物两端的两个交替出现的矩形图形的运动序列，刺激间隔（ISI）各不相同（100 - 500毫秒）。在短ISI时，观察者倾向于报告简单的直线路径运动，即遮挡物之外的运动。但在长ISI时，他们越来越有可能报告遮挡物后面的曲线路径运动。这种报告曲线路径运动的倾向受到图形形状、显示方向、图形与遮挡物之间的间隙以及双眼深度线索的影响。我们的研究结果表明，视觉系统倾向于尽量减少运动物体无法解释的缺失及其路径长度，这样当弯曲遮挡物后面的运动轨迹进行无模态整合能够解释ISI期间物体的客观不可见性时，AM就会偏离最短路径。
