抄録
A concentric-circular pattern illusion was studied with the inner circle as the test field (TF) and the surrounding ring-shaped area as the inducing field (IF), to clarify the effects of the IF-lightness and of the depth relation between TF and IF on induction. In the condition of TF in front of IF, when IF became whiter and farther away, the usually observed distance paradox as a function of the size of IF tended to disappear and was replaced by a monotonic decreasing function. In the condition TF behind IF, the distance paradox was observed in any lightness or depth conditions. Contour was found to be another influential factor on illusion. Results were interpreted from the concept of “object” character of the stimulus.
