p396fig11.35 Three properties of bipole boundary grouping in V2 can explain how boundaries oscillate in response to rivalry-inducing stimuli.  Because all boundaries are invisible, however, these properties are not sufficient to generate a conscious percept of rivalrous surfaces.<BR>||  3 V2 boundary properties cause binocular rivalry.  1. Bipole grouping, 2. Orientational competition, 3. Actovity-dependent habituation