Moving cast shadows induce apparent motion in depth
Moving cast shadows induce apparent motion in depth
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DOI：
10.1068/p260171
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发表时间：
1997-01-01
期刊：
影响因子：
1.7
通讯作者：
Knill, DC
中科院分区：
文献类型：
--
作者：
Kersten, D;Mamassian, P;Knill, DC
现象上强烈的视错觉，其中一个对象的运动投射的阴影决定了感知的三维轨迹的对象。简单地调整阴影的运动足以引起投射阴影的对象的显著不同的表观轨迹。心理物理学的结果与使用的3-D图形的报告表明：（i）提供的信息由一个对象的阴影运动压倒其他强大的信息来源和感知偏差，如恒定的对象大小和一般的观点的假设;（ii）阴影暗度的自然约束在将运动图像块解释为阴影中起作用，但是在某些条件下，甚至不自然的光阴影也可以引起物体深度上的明显运动;（iii）当阴影运动由移动光源引起时，视觉系统错误地将阴影运动解释为与移动物体一致，而不是与移动光源一致。研究结果支持这一假设，即人类视觉系统采用了固定光源的限制在感知处理的空间布局的场景。
Phenomenally strong visual illusions are described in which the motion of an object's cast shadow determines the perceived 3-D trajectory of the object. Simply adjusting the motion of a shadow is sufficient to induce dramatically different apparent trajectories of the object casting the shadow. Psychophysical results obtained with the use of 3-D graphics are reported which show that: (i) the information provided by the motion of an object's shadow overrides other strong sources of information and perceptual biases, such as the assumption of constant object size and a general viewpoint; (ii) the natural constraint of shadow darkness plays a role in the interpretation of a moving image patch as a shadow, but under some conditions even unnatural light shadows can induce apparent motion in depth of an object; (iii) when shadow motion is caused by a moving light source, the visual system incorrectly interprets the shadow motion as consistent with a moving object, rather than a moving light source. The results support the hypothesis that the human visual system incorporates a stationary light-source constraint in the perceptual processing of spatial layout of scenes.