Color contrast and stratification of transparent figures.

Figure/background organization usually entails that figures are perceived in front of the background, and in special conditions front objects appear transparent. Moreover,depth stratification is constrained by the color contrast between specific areas also when transparency is perceived. In four experiments, we showed that contrast affects surface stratification even when it is artificially produced by Cornsweet illusory contrasts, both by increasing and decreasing the color difference just at the border of the adjacent areas, and also when the colors of all areas, complementary and equiluminant included, are kept constant.The results agree with previous findings in the achromatic domain, both with opaque and transparent colors (Masin, 2000) and stress the relevance of the perceived contrast, instead of color differences, on the perception of transparency and stratification.