Norman J F, Todd J T
Department of Psychology, Ohio State University, Columbus 43210.
J Exp Psychol Hum Percept Perform. 1994 Apr;20(2):343-56. doi: 10.1037//0096-1523.20.2.343.
Three experiments were designed to examine the abilities of observers to determine an object's 3-dimensional structure and motion from various types of optical deformations. Observers were required to discriminate whether pairs of moving ellipsoids were rotating rigidly about a single axis or nonrigidly about different axes that varied in slant. Discrimination thresholds were significantly influenced by whether the ellipsoids were intersecting or nonintersecting and whether they contained identifiable texture elements. Performance was unaffected by precession movements of the axis of rotation, by increasing the number of intersecting ellipsoids beyond 2, or by replacing the deforming silhouettes with the projected motions of cast shadows presented in isolation against a planar background. These findings indicate that observers can perceive structure from motion based on several different types of optical deformation, including the deformations of shadows and silhouettes that do not contain identifiable features on which most existing theoretical analyses are designed to operate.
设计了三个实验来检验观察者从各种类型的光学变形中确定物体三维结构和运动的能力。要求观察者辨别成对的移动椭球体是绕单一轴刚性旋转，还是绕倾斜度不同的不同轴非刚性旋转。辨别阈值受到椭球体是否相交以及它们是否包含可识别纹理元素的显著影响。旋转轴的进动运动、将相交椭球体的数量增加到2个以上，或者用孤立地呈现在平面背景上的投射阴影的投影运动取代变形轮廓，对表现均无影响。这些发现表明，观察者可以基于几种不同类型的光学变形，包括阴影和轮廓的变形，从运动中感知结构，而这些变形不包含大多数现有理论分析所设计的可识别特征。
