Norman J F, Todd J T, Perotti V J, Tittle J S
Department of Psychology, Ohio State University, Columbus 43210-1222.
J Exp Psychol Hum Percept Perform. 1996 Feb;22(1):173-86. doi: 10.1037//0096-1523.22.1.173.
A set of 4 experiments evaluated observers' sensitivity to three-dimensional (3-D) length, using both discrimination and adjustment paradigms with computer-generated optical patterns and real objects viewed directly in a natural environment. Although observers were highly sensitive to small differences in two-dimensional length for line segments presented in the frontoparallel plane, their discrimination thresholds increased by an order of magnitude when the line segments were presented at random orientations in 3-D space. There were also large failures of constancy, such that the perception of 3-D length varied systematically with viewing distance, even under full-cue conditions.
一组4个实验评估了观察者对三维（3-D）长度的敏感度，实验采用了辨别和调整范式，使用计算机生成的光学图案以及在自然环境中直接观察的真实物体。尽管观察者对在额状平行平面中呈现的线段的二维长度的微小差异高度敏感，但当线段在三维空间中以随机方向呈现时，他们的辨别阈值增加了一个数量级。同时还存在大量的恒常性失效情况，以至于即使在全线索条件下，三维长度的感知也会随着观察距离而系统地变化。
