Effect of Attention on the Initiation of Binocular Rivalry

Recent studies suggest that attention is necessary for perceptual alternations in binocular rivalry. It has been shown that attention plays a role in not only accelerating but also even enabling perceptual fluctuation in ongoing phase of binocular rivalry. In this study, we tested whether attention also plays a role in suppressing a rival stimulus in its initial phases by measuring proportions of mixed dominance. We hypothesized that when attention is directed toward the location of rival stimuli prior to their presentation, the proportion of mixed dominance is lower than when attention is directed away from that location because of attentional facilitation. However, we found that the proportion of mixed dominance did not differ depending on the locus of attention, although we adopted well-established experimental paradigms for manipulating spatial attention. This result suggests that attention is not a determining factor in establishing initial perceptual dominance in binocular rivalry.