Monocular analogues to binocular contour rivalry

Monocular phenomenological analogues to binocular contour rivalry were demonstrated with after-images. Evidence was presented that the term “contour rivalry” is justified for the monocular analogue. Monocular contour rivalry seems to be a cortical phenomenon as is binocular contour rivalry. Intersection of contours may develop in a monocular after-image by filling-in of contours. The filling-in alternates as the contour dominance alternates. In binocular and in monocular contour rivalry halos of suppression are observed which have similar dimensions under similar conditions.