Figure 1.

(Left) The appearance of the Mondrian stimulus in our experiments with the five patches used as targets. The natural colors seen here change little with changes in illumination (color constancy); the void color of each patch under each particular illumination used is described in Table 1. (Right) Normal versus dichoptic presentation results. Each of the Mondrian/target pairs was presented a total of 100 times, 50 times separating Mondrian and target between the two eyes and 50 times presenting both to the same eye (see Experimental Procedures). With the exception of a few trials in which subjects were uncertain (most probably because of an instant lack of concentration), they always reported seeing color A (natural) in normal and color B (void) in dichoptic presentations; the opposite was never the case.