κ感度に基づく同心円錯視の説明
1969 年 40 巻 2 号 p. 85-94
詳細
1969 年 40 巻 2 号 p. 85-94
Light threshold increases as the distance between a test spot and an inducing figure decreases. CFF also becomes larger as a test spot approaches the figure. However, Ogasawara (1961) indicates that the two results are opposing each other in terms of light sensitivity. In a previous report (this Journal, 1967, 33, 1-13) this contradiction was explained on the basis of the results of measurements of On-and Off-responses in the human fovea. At the same time the present writer proposed a hypothesis that light sensitivity possesses two aspects, τ and κ (τ-sensitivity is generally measured in terms of light threshold, and κ-sensitivity in terms of CFF).
The purpose of the present study is to test whether or not various characteristics of the illusion of concentric circles are explained on the basis of the above hypothesis. The important characteristics of the illusion explained are as follows.
1. The displacement effect of inner circle is positive.
2. The displacement effect of outer circle is negative.
3. The amount of the displacement effect increases with the increase of the distance between the outer and inner circles up to a certain point and then gradually diminishes.
4. The amount of the displacement effect of the inner circle, in general, is greater than that of the outer circle.
5. The maximum displacement effect appears when the ratio of the diameters of the concentric circles is about 2:3.
