Tse P U
Harvard University Vision Sciences Lab, USA.
Cogn Psychol. 1999 Aug;39(1):37-68. doi: 10.1006/cogp.1999.0715.
The visual system completes image fragments into larger regions when those fragments are taken to be the visible portions of an occluded object. Kellman and Shipley (1991) argued that this "amodal" completion is based on the way that the contours of image fragments "relate." Contours relate when their imaginary extensions intersect at an obtuse or right angle. However, it is shown here that contour relatability is neither necessary nor sufficient for completion to take place. Demonstrations that go beyond traditional examples of overlapping flat surfaces reveal that "mergeable" volumes, rather than relatable contours, are the critical elements in completion phenomena. A volume is defined as a 3-D enclosure. Typically, this refers to a surface plus the inside that it encloses. Two volumes are mergeable when their unbounded visible surfaces are relatable or the insides enclosed by those surfaces can completely merge. Two surfaces are relatable when their visible portions can be extended into occluded space along the trajectories defined by their respective curvatures so that they merge into a common surface. A volume-based account of amodal completion subsumes surface completion as a special case and explains examples that neither a contour- nor a surface-based account can explain.
当图像片段被视为被遮挡物体的可见部分时，视觉系统会将这些片段组合成更大的区域。凯尔曼和希普利（1991）认为，这种“非模态”完成是基于图像片段轮廓“关联”的方式。当轮廓的假想延伸线以钝角或直角相交时，轮廓相互关联。然而，本文表明，轮廓的可关联性对于完成这一过程既不是必要条件也不是充分条件。超越传统重叠平面示例的演示表明，“可合并”的体积，而非可关联的轮廓，才是完成现象中的关键要素。体积被定义为一个三维封闭空间。通常，这指的是一个表面及其所包围的内部空间。当两个体积的无界可见表面可关联，或者这些表面所包围的内部空间能够完全合并时，这两个体积就是可合并的。当两个表面的可见部分能够沿着由各自曲率定义的轨迹延伸到被遮挡空间，从而合并成一个共同表面时，这两个表面就是可关联的。基于体积的非模态完成解释将表面完成视为一种特殊情况，并解释了基于轮廓和基于表面的解释都无法解释的示例。
