Subjective appearance of ambiguous structure-from-motion can be driven by objective switches of a separate less ambiguous context

Two ambiguous transparent structure-from-motion (SFM) stimuli often appear to co-rotate. Grossmann & Dobbins (2003) reported breakdown of such perceptual coupling when one stimulus was made unambiguous (by rendering it opaque), leading them to propose that coupling depends generally on differential stimulus ambiguity. In contrast, we demonstrate robust stimulus-driven coupling even when one SFM stimulus is relatively disambiguated, by using relative-luminance and/or binocular-disparity cues. Such context stimuli could induce stimulus-driven coupling by disambiguating the transparent stimulus, though critically only when the context was clearly non-opaque and coaxial with the ambiguous stimulus. This demonstrates long-range information-sharing between separate stimulus representations, subject to specific constraints.