Breaking and restoring ocular balance: Temporal interactions in binocular rivalry and stereopsis

Binocular integration and interocular suppression are fundamental processes underlying binocular vision, giving rise to stereopsis and binocular rivalry, respectively. To investigate how the visual system dynamically coordinates these processes to form a unified percept, we conducted four psychophysical experiments examining the temporal interactions between binocular rivalry and stereopsis. In Experiment 1a, binocular rivalry, especially with high-contrast stimuli, impaired subsequent stereopsis, significantly elevating average stereo detection thresholds from 60.5 to 111.8 arcsec. Experiment 1b revealed no effect on contrast detection, confirming that the suppression was specific to stereopsis rather than due to general attentional distraction. Experiment 2a revealed that preceding stereopsis rebalanced subsequent rivalry dynamics by reducing ocular dominance asymmetry and increasing mixed percepts, without affecting alternation rate. Experiment 2b further demonstrated that anti-correlated stereograms, which do not elicit stable stereopsis, exerted no effect on subsequent rivalry dynamics. These findings underscore a dynamic interplay between binocular integration and suppression in resolving perceptual ambiguity and achieving unified visual perception. Crucially, our results reinforce that stereopsis is not merely a passive consequence of binocular integration, but actively contributes to rebalancing ocular dominance, thus offering insights for interventions aimed at restoring binocular function.