Satiation effects with reversible figures.

Three experiments were performed to examine the rate at which reversible perspective figures (Necker cubes) undergo apparent reversal, as a function of selected stimulus variables. 100 subjects were instructed not to inhibit or to promote reversals of perspective, but to remain neutral. The data indicated: (1) an incomplete cube reverses less frequently than does a corresponding complete figure, (2) two adjacent cubes reverse in synchrony when of equal luminance but often out of phase when differing in luminance, (3) a shift of the cube's retinal position causes its reversal rate to drop to baseline level. These results suggest that the reversal effect increases over time due to a localized rather than general process, and are thus compatible with a sensory satiation model of perceptual alternation.