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Abstract

Presentation of different visual stimuli to the two eyes results in alternation between the perception of one stimulus and the other, a phenomenon known as binocular rivalry. While these perceptual shifts clearly can arise from endogenous mechanisms, they can be also be caused by external stimulus changes, such as in the paradigm of flash suppression (Wolfe, 1984). We have previously shown that rivalry can emerge between dichoptic patterns that are rapidly switched between the eyes. In this interocular switching (IOS) paradigm, perception of each stimulus can endure for several seconds and span many physical stimulus swaps. Interestingly, the amount of stable unitary perception experienced with these stimuli is very sensitive to the temporal frequency of the stimulus switches as well as the contrast and similarity of the rivaling stimuli. The current study aims to better understand the determinants of perception in IOS rivalry by examining several aspects of its temporal characteristics. In particular, we investigated whether global stimulus perturbations, such as stimulus blanking, flicker, and flash suppression, have similar perceptual consequences for IOS rivalry as for normal rivalry. Several parameters of flicker are under study, including interocular and interstimulus differences in flicker rate. In addition, we are examining the detectability of sudden stimulus alterations in IOS rivalry over a range of switch rates and contrast values.