An increasing number of studies use subjective reports of visibility, so as to delineate the domain of perceptual awareness. It is generally assumed that degrees of visibility can be ordered on a single unidimensional scale. Here, I put this assumption to test with metacontrast, one of the most studied visual masking paradigms. By means of…

Stabilization of the retinal image of the boundary between a pair of red/green or yellow/blue stripes, but not their outer edges, results in the entire region being perceived simultaneously as both red/green or yellow/blue. This suggests that the percepts of reddish-green/yellowish-blue apparently are possible in corticocortical color vision…