Binocular rivalry between complex stimuli in split-brain observers

We investigated binocular rivalry in the two cerebral hemispheres of callosotomized (split-brain) observers. We found that rivalry occurs for complex stimuli in split-brain observers, and that it is similar in the two hemispheres. This poses difficulties for two theories of rivalry: (1) that rivalry occurs because of switching of activity between the two hemispheres, and (2) that rivalry is controlled by a structure in the right frontoparietal cortex. Instead, similar rivalry from the two hemispheres is consistent with a theory that its mechanism is low in the visual system, at which each hemisphere conducts a similar analysis of its half of visual space