Figure 7.

Example data illustrating perceptual stabilization. (a) During a 5-min block of continuous presentation of the rotating sphere stimulus, observers reported spontaneous alternations between the two possible percepts (clockwise or anti-clockwise rotation), at a rate that varies between individuals. (b) When the same stimulus was presented intermittently (in a 1 s on, 1 s off cycle) the frequency of perceptual alternations was reduced. The right column shows stabilization indices (S.I.) based on all of the data collected for each observer (see the electronic supplementary materials, equation S3 for details).