abolished. When he asked observers specifically to move their eyes over one stimulus, that stimulus predominated in rivalry. He could also increase predominance of a stimulus by increasing the number of its contours, by moving it, by reducing its size, by making it brighter, and by contracting the muscles on the same side of the body as the eye viewing that stimulus. Breese also showed that rivalry occurs between afterimages. Breese also discovered the phenomenon of monocular rivalry: if the two rival stimuli are optically superimposed to the same eye and one fixates on the stimuli, then alternations in the clarity of the two stimuli are seen. Occasionally, one image disappears altogether, as in binocular rivalry, although this is much rarer than in binocular rivalry. Other senses Auditory and olfactory forms of perceptual rivalry can occur when there are conflicting and so rivaling inputs into the two ears or two nostrils. See also Binocular summation Binocular Rivalry Described by Quantum Formalism Binocular vision Diplopia References O’Shea, R.P. (1999) l Translation O’Shea, R.P. (1999) l Translation Further reading Wikibooks: Consciousness Studies — Effects of psilocybin on binocular rivalry. External links Vision Visual perception Consciousness studies