Binocular Rivalry in Half-Occluded Regions of Coloured Stereograms Where the Background is a Drifting Grating

Binocular rivalry in half-occluded (HO) regions was studied with coloured stereograms where the background was a drifting grating. The coloured stereograms consisted of a central square-shaped region, a background, and HO regions. The central square-shaped region was coloured green, and was presented in either crossed or uncrossed disparity. The background was a stationary or drifting vertical grating consisting of white and grey bars. The HO regions were coloured blue, and the luminance was fixed or was changed consistently with the drifting grating in the background. Subjects judged the disappearance of the HO regions, and the cumulative time of disappearance was measured during a 30 s period. When the luminance of the HO regions was fixed against the background of a drifting grating, the disappearance time was the same as for the static grating background. However, when the luminance of the HO regions was modulated consistently with the drifting background grating, the cumulative disappearance time was significantly less than when the background was a static grating. These results suggest that the HO regions escape binocular rivalry when they correlate with the background.