Perceptual Rivalry as an Ultradian Oscillation

Perceptual rivalry alternations are switches in perception that occur despite a constant, if ambiguous, sensory input. Whilst being clearly and predictably influenced by the ‘external’ rivalry-inducing stimulus (Levelt, 1965; Mueller & Blake, 1989), these internally driven changes in perceptual state have been found to exhibit rhythmic properties (Carter & Pettigrew, 2003). It is this endogenously driven, externally influencable nature of perceptual rivalry that has motivated the following comparison with the self-sustaining circadian oscillations of biological systems, despite the significant differences in periodicity.