Kim Juno, Jeng Kelly, Anderson Barton L
School of Psychology, University of Sydney, Sydney, New South Wales, 2006, Australia,
Atten Percept Psychophys. 2014 Jan;76(1):98-111. doi: 10.3758/s13414-013-0540-z.
The strength of amodal completion is known to be modulated by contour relationships and global shape. Some researchers have shown that amodal completion also depends on surface similarity, but they have not distinguished the relative importance of similarity in surface representations either pre or post lightness constancy. In the experiments reported here, we aimed to determine whether amodal completion depends on processes that occur either before or after the establishment of lightness constancy. We used computer rendering techniques to vary the consistency of a cast shadow with a decrement in luminance on one side of a partially occluded surface. We found that perceived completion depended on the consistency of the decrement in surface luminance with the orientation of a cast shadow (Exp. 1). In Experiment 2, we generated occluded surface fragments that could be either luminance-matched or lightness-matched to surface fragments on the opposite side of the occluder, and we found that the strength of amodal completion depended primarily on similarity in the perceived surface reflectance. In Experiments 3 and 4, we performed apparent-motion tasks to obtain converging evidence for grouping on the basis of perceived similarity in lightness. We found that matching surfaces in lightness significantly improved the apparent motion of surfaces behind an occluder, as compared with surfaces that were matched in contrast alone. These results suggest that amodal completion depends on the perceived similarity in lightness of partially occluded surface fragments.
已知无模态完成的强度会受到轮廓关系和整体形状的调节。一些研究人员表明，无模态完成还取决于表面相似性，但他们并未区分在明度恒常性之前或之后表面表征中相似性的相对重要性。在本文所报告的实验中，我们旨在确定无模态完成是否取决于在明度恒常性确立之前或之后发生的过程。我们使用计算机渲染技术来改变投射阴影与部分遮挡表面一侧亮度递减的一致性。我们发现，感知到的完成情况取决于表面亮度递减与投射阴影方向的一致性（实验1）。在实验2中，我们生成了被遮挡的表面片段，这些片段可以与遮挡物另一侧的表面片段在亮度上匹配或在明度上匹配，并且我们发现无模态完成的强度主要取决于感知到的表面反射率的相似性。在实验3和实验4中，我们进行了表观运动任务，以获得基于明度感知相似性进行分组的汇聚证据。我们发现，与仅在对比度上匹配的表面相比，在明度上匹配表面显著改善了遮挡物后面表面的表观运动。这些结果表明，无模态完成取决于部分遮挡表面片段在明度上的感知相似性。
