同心環所引發之亮度與色彩偏移與Munker-White效應享有共同機制

Abstract

一塊區域的色彩或亮度表觀會因受周圍的空間配置影響而偏移。其中幾個特定的現象是Munker-White效應（柵狀周邊）與同心環所引發之亮度或色彩誘導（同心環周邊）。我們檢驗了這兩種現象是否有共同機制。在非對稱配對作業中，受試者調整配對區的表觀使其使測試區的表觀配對。測試區的周邊（誘導區）有兩種：方波構成的柵狀或同心環周邊。誘導區在三個色彩方向上變動（白—黑、綠—紅或紫—黃）。對於每種誘導區和在每個色彩方向下，誘導區都有四種對比水準以及兩種相反的色彩配置方式。結果顯示兩種誘導區所引發的亮度或色彩表觀偏移量在各個測試的情境中都高度地相似。進一步的分析顯示誘導的表觀偏移量是誘導區對比的冪函數，並且冪次在兩種不同的誘導區中為相同。這隱含著這些亮度與色彩誘導的現象背後潛藏著共同的機制。

The brightness or color appearance of an area depends on its surrounding spatial configuration. Several particular examples are the Munker-White effect (grating surround) and brightness or color induction from concentric annuli (“bull’s-eye” surround). We examined whether these two phenomena share the same mechanisms. In an asymmetric matching experiment, the task of the observer was to adjust the appearance of a matching patch to match the appearance of a test patch embedded in one of the two types (square wave grating or concentric annuli) of inducing surrounds (inducer). The inducer modulated in one of the three color directions (white-black, green-red, or purple-yellow). There were two opposing phases and four contrast levels for each inducer type and color direction. The results showed that the induced appearance shift of the test patch by both the concentric annuli and the grating surrounds were highly similar for all tested conditions. Further analysis showed that the induced appearance shift was a power function of the inducer contrast and this power was invariant for surround type. This implies that these phenomena may share the same common mechanisms.