Su Yong, He Zijiang J, Ooi Teng Leng
Department of Basic Sciences, Pennsylvania College of Optometry at Salus University, Elkins Park, PA, USA.
J Vis. 2010 Mar 24;10(3):5.1-14. doi: 10.1167/10.3.5.
Our visual system ably integrates the visible parts of a partially occluded surface with the occluded parts (amodal surface completion), mainly by relying on the surface boundary contours of the image. Less known, is whether the visual system also utilizes surface feature information, such as luminance contrast polarity, for surface completion. We conducted three experiments to investigate this issue. Experiment 1 found that when visible segments of a partially occluded rectangle with the same luminance contrast polarity move behind an occluding surface, observers perceive the visible segments as part of the occluded rectangle moving cohesively behind the occluding surface. However, when the visible segments have opposite luminance contrast polarity, the global motion of the segments is barely perceived, suggesting a failure of amodal surface integration. Experiment 2 revealed that this same luminance contrast polarity constraint applies to amodal surface integration of a display without an explicit occluding surface image. Experiment 3 showed that both the shape and luminance contrast polarity of the visible segments of the partially occluded rectangle affect amodal surface completion. Together, these findings demonstrate that luminance contrast polarity, along with surface boundary contour, are important cues for amodal surface integration.
我们的视觉系统主要依靠图像的表面边界轮廓，能够将部分被遮挡表面的可见部分与被遮挡部分整合起来（非模态表面完成）。鲜为人知的是，视觉系统是否也利用表面特征信息（如亮度对比极性）来完成表面整合。我们进行了三项实验来研究这个问题。实验1发现，当具有相同亮度对比极性的部分被遮挡矩形的可见段在遮挡表面后移动时，观察者会将可见段视为在遮挡表面后连贯移动的被遮挡矩形的一部分。然而，当可见段具有相反的亮度对比极性时，几乎无法感知到这些段的整体运动，这表明非模态表面整合失败。实验2表明，相同的亮度对比极性约束适用于没有明确遮挡表面图像的显示器的非模态表面整合。实验3表明，部分被遮挡矩形的可见段的形状和亮度对比极性都会影响非模态表面完成。这些发现共同表明，亮度对比极性与表面边界轮廓一样，是非模态表面整合的重要线索。
