Taya Shuichiro, Miura Kayo
Department of Psychology, University of Surrey, Guildford, England.
Atten Percept Psychophys. 2010 Oct;72(7):1930-7. doi: 10.3758/APP.72.7.1930.
Observers tend to localize the final position of a suddenly vanished moving target farther along in the direction of the target motion (representational momentum). We report here that such localization errors are mediated by perceived motion rather than by retinal motion. By manipulating the cast shadow of a moving target, we induced illusory motion to a target stimulus while keeping the retinal motion constant. Participants indicated the vanishing point of the target by directing a mouse cursor. The resulting magnitude of localization errors was modulated on the basis of the induced direction of the target. Such systematic localization biases were not obtained in a control condition in which the motion paths of the ball and shadow were switched. Our results suggest that cues to object motion trajectory, such as cast shadows, are used for the localization task, supporting a view that a predictive mechanism is responsible for the production of localization errors.
观察者往往会将突然消失的移动目标的最终位置定位在目标运动方向更远的地方（表征动量）。我们在此报告，这种定位误差是由感知到的运动介导的，而非视网膜运动。通过操纵移动目标的投射阴影，我们在保持视网膜运动不变的情况下，使目标刺激产生了虚幻运动。参与者通过移动鼠标光标来指示目标的消失点。由此产生的定位误差大小根据目标的诱导方向进行了调节。在球和阴影的运动路径被切换的控制条件下，并未获得这种系统性的定位偏差。我们的结果表明，诸如投射阴影等物体运动轨迹线索被用于定位任务，支持了一种观点，即预测机制是产生定位误差的原因。
