Effects of Form in Koffka-Ring Type Patterns (2): Examination of Area-Ratio of test Figure to Inducing Figure in Hue Contrast
T. Hanari, M. Ito, S. Takahashi, S. Nakamura, H. Nonami & T. Goto
This study examined how the area-ratio of a non-annular test figure (TF) to an inducing figure (IF) affected simultaneous hue contrasts in Koffka-ring type patterns. We manipulated three stimulus conditions (three degrees of area, three degrees of joint-ratio, and two states of division) of the TF, systematically. Four subjects were asked to report, through matching, the apparent hue of the 'T"F overlapped on the red-green IF. The results revealed that the magnitudes of hue contrast (MHCs) decreased significantly as the TF's area increased in the divided TFs, whereas the MHCs remained unchanged in the undivided TFs. Further, as the degree of joint-ratio increased in different sizes of both the divided TF and the undivided TF, the MHCs were found to decrease. In conclusion, the joint-ratio of the TF affected the simultaneous hue contrast in Koffka-ring type patterns independently of changing the area-ratio, while the effects of the area were produced only in the divided TF.

Key words: simultaneous hue contrast, Koffka-ring type pattern, area-ratio, joint-ratio, division