Norman J F, Todd J T
Department of Psychology, Ohio State University, Columbus 43210.
Percept Psychophys. 1993 Mar;53(3):279-91. doi: 10.3758/bf03205183.
In two experiments, we evaluated the ability of human observers to make use of second-order temporal relations across three or more views of an apparent motion sequence for the perceptual analysis of three-dimensional form. Ratings of perceived rigidity were obtained in Experiment 1 for objects rotating in depth that were simultaneously subjected to sinusoidal affine stretching transformations along the line of sight or in a direction parallel to the image plane. Such transformations are theoretically interesting because they cannot be detected by analyses that are restricted to first-order temporal relations (i.e., two views), but they can be detected by more conventional analyses of structure from motion in which second-order temporal relations over three or more views are used. The current results show that human observers can perceive stretching transformations of a rotating 3-D object in a direction parallel to the image plane but that they fail to perceive stretching transformations along the line of sight. This result suggests that human observers can make use of some limited second-order temporal information. This finding was confirmed in Experiment 2, in which we investigated the effects of several specific optical consequences of sinusoidal stretching transformations applied in different directions. The results indicate that observers may be sensitive to the sign of acceleration, but that they cannot make use of the precise magnitude of second-order relations necessary to recover euclidean metric structure.
在两项实验中，我们评估了人类观察者利用表观运动序列的三个或更多视图之间的二阶时间关系进行三维形状感知分析的能力。在实验1中，对于在深度上旋转的物体，同时沿着视线方向或平行于图像平面的方向进行正弦仿射拉伸变换，获得了感知刚性的评分。这种变换在理论上很有趣，因为它们不能通过仅限于一阶时间关系（即两个视图）的分析来检测，但可以通过更传统的从运动中分析结构来检测，其中使用了三个或更多视图之间的二阶时间关系。当前结果表明，人类观察者能够感知旋转的三维物体在平行于图像平面方向上的拉伸变换，但无法感知沿视线方向的拉伸变换。这一结果表明人类观察者可以利用一些有限的二阶时间信息。这一发现在实验2中得到了证实，在实验2中我们研究了在不同方向上应用正弦拉伸变换的几种特定光学结果的影响。结果表明，观察者可能对加速度的符号敏感，但他们无法利用恢复欧几里得度量结构所需的二阶关系的精确大小。
