Orientation tuning of shape from shading.
Orientation tuning of shape from shading.
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通过阴影调整形状的方向。
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
K. Humphrey
中科院分区：
文献类型：
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作者：
L. A. Symons;F. Cuddy;K. Humphrey
进行了四个实验，以评估不同的方向和照明方向的阴影或二分盘的视觉处理的效果。在前两个实验中，观察者被呈现从0度到180度的九个不同的阴影方向。当阴影梯度的方向不是水平（90度）或67.5度时，以快速和平行的方式检测阴影盘的目标。搜索不对称有利于检测“麻点”目标的“球”目标被发现的所有方向。在0度、22.5度和90度方向上，对二分盘的搜索率与阴影盘相似，但对中间方向的搜索率不同，也没有发现搜索不对称性，这些差异表明阴影显示和二分显示是由不同的潜在机制处理的。第三个实验表明，光源的方向（左或右）对90度点周围的搜索不对称性没有影响。在第四个实验中，阴影梯度方向影响深度的大小估计。这些实验表明，视觉系统对头顶照明的“假设”是广泛调整的。
Four experiments were performed to assess the effect of different orientations and direction of lighting on the visual processing of shaded or bipartite disks. In the first two experiments, observers were presented with nine different shading orientations from 0 degree to 180 degrees. Targets were detected in a rapid and parallel fashion for shaded disks when the orientation of the shading gradient was not horizontal (90 degrees) or oriented at 67.5 degrees. Search asymmetries favoring the detection of "pock" targets over "ball" targets were found for all orientations. The search rates for bipartite disks were similar to the shaded disks at 0 degree, 22.5 degrees, and 90 degrees but not for intermediate orientations, and no search asymmetries were found. These differences suggest that shaded displays and bipartite displays are processed by different underlying mechanisms. The third experiment showed that the direction of the light source (left or right) had no influence on search asymmetries around the 90 degrees point. Shading gradient orientation affected magnitude estimates of depth in the fourth experiment. These experiments show that the visual system's "assumption" of overhead lighting is broadly tuned.