Abstract
Stimulus rivalry is a variant of binocular rivalry where the two competing images are rapidly and repeatedly swapped between the eyes. Perceptual dominance periods of a given image can extend across many eye swaps during stimulus rivalry, which has led to the view that stimulus rivalry relies on eye-independent neural processes, consistent with a neural origin beyond early visual cortex. In our first experiment we measured the threshold elevation aftereffect (TEAE) following adaptation to an image engaged in stimulus rivalry, and compared this to a situation where the adapter was not rivaling. We observed reduced TEAEs following stimulus rivalry, indicating diminished contrast adaptation during stimulus-rivalry suppression. This result suggests that stimulus rivalry arises in part in or before early visual cortex, the putative locus of the TEAE. Contrast adaptation is partly eye specific, and in a second experiment we investigated this eye-specific component during stimulus rivalry. During stimulus rivalry each image is alternately projected into the left eye and into the right eye, and we found that suppression of an images at a given moment specifically diminished adaptation associated with the eye viewing the image at that moment. Considered together, these results suggest that the neural events at the basis of stimulus rivalry include events at eye-specific stages at or before early visual cortex. We have developed a computational model of stimulus rivalry that successfully implements this idea.
Meeting abstract presented at VSS 2013