A Common Oscillator for Perceptual Rivalries?

Perceptual rivalry causes conscious experience to oscillate even when sensory input stays constant. The neural site of binocular rivalry, a well-known form, remains debated, with different cortical regions implicated. This work shows that the temporal pattern of disappearances and reappearances in motion-induced blindness (MIB) closely correlates with binocular rivalry patterns within the same individual, across wide inter-individual variation. The hallucinogen LSD increases rhythmicity in both phenomena identically. MIB also shares two hallmark properties of binocular rivalry: dominance periods approximate a gamma distribution, and increasing one perceptual phase's predominance reduces the opposing phase's time, consistent with Levelt's second proposition. The authors conclude MIB is a form of perceptual rivalry and that a common oscillator may time all such oscillations.

Study at a glance

Abstract

Perceptual rivalry is an oscillation of conscious experience that takes place despite univarying. if ambiguous, sensory input. Much current interest is focused on the controversy over the neural site of binocular rivalry, a variety of perceptual rivalry for which a number of different cortical regions have been implicated. Debate continues over the relative role of higher levels of processing compared with primary visual cortex and the suggestion that different forms of rivalry involve different cortical areas. Here we show that the temporal pattern of disappearance and reappearance in motion-induced blindness (MIB) (Bonneh et al, 2001 Nature 411 798-801) is highly correlated with the pattern of oscillation reported during binocular rivalry in the same individual. This correlation holds over a wide range of inter-individual variation. Temporal similarity in the two phenomena was strikingly confirmed by the effects of the hallucinogen LSD, which produced the same, extraordinary, pattern of increased rhythmicity in both kinds of perceptual oscillation. Furthermore. MIB demonstrates the two properties previously considered characteristic of binocular rivalry. Namely the distribution of dominance periods can be approximated by a gamma distribution and, in line with Levelt's second proposition of binocular rivalry, predominance of one perceptual phase can be increased through a reduction in the predominance time of the opposing phase. We conclude that (i) MIB is a form of perceptual rivalry, and (ii) there may be a common oscillator responsible for timing aspects of all forms of perceptual rivalry.