抄録
Two experiments were designed to examine the existence of lower versus upper visual field anisotropy in form perception based on shading and edge-based information. In the experiments, subjects were asked to judge the visual property of the stimulus defined by shading or edge. The results demonstrated that the lower visual field is specialized for the processing of shading information, whereas the upper field is specialized for the processing of edge-based information. These findings are consistent with Previc’s (1990) hypothesis that the processing of optically degraded images is linked to a peripersonal visual system which is biased to the lower visual field, while an extrapersonal visual system, which is biased toward the upper visual field, is used for the processing of details of form.