Binocular rivalry and dichoptic masking: suppressed stimuli do not mask stimuli in a dominating eye.

Reaction time was used to gauge the sensitivity of an eye during its dominant and suppressed phases of binocular rivalry. During dominance, performance was uniformly good in detecting both stimuli that were spatially identical to the suppressed stimulus and those that were different in spatial frequency. When suppressed eyes were tested, performance was poor when the stimulus was different from the dominating stimulus, but even worse when the test stimulus and the dominating stimulus were spatially identical. The results favor the view that suppression operates nonselectively on a monocular visual channel, prior to the point at which dichoptic pattern masking occurs.