Harp Thomas D, Bressler David W, Whitney David
Department of Psychology, University of California, Davis, CA, USA.
J Vis. 2007 Jul 20;7(2):15.1-13. doi: 10.1167/7.2.15.
Adaptation to first-order (luminance defined) motion produces not only a motion aftereffect but also a position aftereffect, in which a target pattern's perceived location is shifted opposite the direction of adaptation. These aftereffects can occur passively (when the direction of motion adaptation cannot be detected) and remotely (when the target is not at the site of adaptation). Although second-order (contrast defined) motion produces these aftereffects, it is unclear whether they can occur passively or remotely. To address these questions, we conducted two experiments. In the first, we used crowding to remove a local adapter's second-order motion from awareness and still found a significant position aftereffect. In the second experiment, we found that the direction of motion in one region of a crowded array could produce a position aftereffect in an unadapted, spatially separated region of the crowded array. The results suggest that second-order motion influences perceived position over a large spatial range even without awareness.
对一阶（由亮度定义）运动的适应不仅会产生运动后效，还会产生位置后效，即目标图案的感知位置会朝着与适应方向相反的方向偏移。这些后效可以被动地发生（当无法检测到运动适应的方向时），也可以远距离发生（当目标不在适应部位时）。尽管二阶（由对比度定义）运动也会产生这些后效，但尚不清楚它们是否能被动地或远距离地发生。为了解决这些问题，我们进行了两项实验。在第一个实验中，我们利用拥挤效应使局部适配器的二阶运动从意识中消失，但仍发现了显著的位置后效。在第二个实验中，我们发现拥挤阵列中一个区域的运动方向可以在拥挤阵列中一个未适应的、空间上分离的区域产生位置后效。结果表明，即使在没有意识的情况下，二阶运动也会在很大的空间范围内影响感知位置。
