RT Journal Article SR Electronic T1 Extending Levelt’s Propositions to perceptual multistability involving interocular grouping JF bioRxiv FD Cold Spring Harbor Laboratory SP 057232 DO 10.1101/057232 A1 Alain Jacot-Guillarmod A1 Yunjiao Wang A1 Claudia Pedroza A1 Haluk Ogmen A1 Zachary Kilpatrick A1 Krešimir Josić YR 2016 UL http://biorxiv.org/content/early/2016/06/05/057232.abstract AB Levelt’s Propositions have been a touchstone for experimental and modeling studies of perceptual multistability. We asked whether Levelt’s Propositions extend to perceptual multistability involving interocular grouping. To address this question we used split-grating stimuli withcomplementary halves of the same color. As in previous studies, subjects reported four percepts in alternation: the two stimuli presented to each eye (single-eye percepts), as well as two interocularly grouped, single color percepts (grouped percepts). Most subjects responded to increased color saturation by more frequently reporting a single color image, thus increasingthe predominance of grouped percepts (Levelt’s Proposition I). In these subjects increased predominance was due to a decrease in the average dominance duration of single-eye percepts, while that of grouped percepts remained largely unaffected. This is in accordance with generalized Levelt’s Proposition II which posits that the average dominance duration of the stronger (in this case single-eye) percept is primarily affectedbychanges in stimulus strength. In accordance with Proposition III, thealternation rate increased as the difference in the strength of the percepts decreased. To explain the mechanism behind these observations, we introduce a hierarchical model consisting of low-level neural populations, eachresponding to input at a visual hemifield, and higher-level populations representing the percepts. The model exhibits the changes in dominance durationobserved in the data, and conforms to all of Levelt’s Propositions.