Colour transparency and figure/ground stratification

In the first experiment we found that the apparent stratification of two superimposed diamonds, i.e. which of the two diamond appears transparent and in front, can be inverted by changing the hue and/or the chromaticness of the intersection area, and that the apparent stratification significantly depends on the chromatic similarity between the colour of this area and the colours of both the adjacent areas. The hue of the background seemed to have no effect in the diamond stratification. In the second experiment results confirmed that the chromatic aspects of the background colours are irrelevant in determining the stratification of the diamonds, but only rather large luminance differences are necessary to affect it, in agreement with the results by Masin (2000). We can then concluded that in phenomenal transparency the luminance channel plays a predominant role as respect to the chromatic one, but when colours are equiluminant chromatic similarity is crucial in the intersection area of the two overlapping figures.