Visual mechanisms underlying non-assimilative color spreading in the watercolor effect(Summary of Awarded Presentation at the 30th Annual Meeting)

抄録

When a colored line is juxtaposed with a darker contour, its color will spread over the area enclosed by the line (watercolor effect). Although this spreading is assimilative, non-assimilative color spreading has also been demonstrated using the same spatial configuration; e.g., when the inner contour is black and the outer contour is blue, yellow spreading can be observed. We previously reported that the optimal luminance conditions for these two types of color spreading differ, and that the two types of spreading can simultaneously occur on opposite sides of the contours. Extending the previous study, this study investigates the conditions for non-assimilative color spreading with an emphasis on the contribution of S-cone signals. The results demonstrate that non-assimilative spreading is stronger when the outer contour has a larger S-cone contrast than the inner contour. Thus, the present study suggests that the interaction between luminance and the S-cone signals is critical for non-assimilative spreading, and that different mechanisms contribute to different types of color spreading in the watercolor configuration.