Perceptual alternation in viewing bistable stimuli can be slowed or halted if the stimuli are presented intermittently [1, 2]. Memory of the recent perceptual experience has been proposed to explain this stabilization effect. But the nature of this "perceptual memory" remains unclear. By using a bistable rotating cylinder and two dichoptically presented orthogonal gratings, we explored the features that are important for the stabilization by changing a particular feature of the stimuli between alternate presentations. For the rotating cylinder, changing its color, rotating speed, size, or its stereo depth had no or minimal effect on the stabilization of its perceived rotation direction. For binocular rivalry, when the two gratings were matched in strength and then swapped between the two eyes synchronously with the intermittent presentation, the percepts were usually stabilized to one eye. In both cases, perceptual stabilization occurred only if the stimuli were presented to the same retinal location. These results suggest that the stabilization of monocular bistable stimuli is likely due to the removal of local adaptation, insensitive to the features that define the object identity. For binocular rivalry, preservation of the direction of interocular suppression rather than memory of the stimulus identity accounts for the stabilization effect.
Bibliographical noteFunding Information:
Results of this study were presented as a poster at the 2003 Vision Sciences Society meeting in Sarasota, Florida. We thank Wendy Davis and Patricia Costello for their comments on an early version of the draft. This work was supported by a 21 st Century Research Award from the James S. McDonnell Foundation and a grant from National Science Foundation of China (#30328017).