Binocular rivalry of equiluminant targets

We describe a stimulus pattern designed for use in test probe investigations of binocular rivalry. The pattern consists of a contour-free disk that is identical in luminance in both eyes surrounded by a dimmer annulus in one eye and a brighter annulus in the other. Temporal characteristics of rival alternations can be controlled by manipulating luminance of the annuli. Sensitivity to probes inserted in the rival region can be measured uncontaminated by differences in the adaptation state of the eyes or pattern masking.