Cognition modulates action-to-perception transfer in ambiguous perception.

Can cognition penetrate action-to-perception transfer? Participants observed a structure-from-motion cylinder of ambiguous rotation direction. Beforehand, they experienced one of two mechanical models: An unambiguous cylinder was connected to a rod by either a belt (cylinder and rod rotating in the same direction) or by gears (both rotating in opposite directions). During ambiguous cylinder presentation, mechanics and rod were invisible, making both conditions visually identical. Observers inferred the rod's direction from their moment-by-moment subjective perceptual interpretation of the ambiguous cylinder. They reported the (hidden) rod's direction by rotating a manipulandum in either the same or the opposite direction. With respect to their effect on perceptual stability, the resulting match/nonmatch between perceived cylinder rotation and manipulandum rotation showed a significant interaction with the cognitive model they had previously been biased with. For the "belt" model, congruency between cylinder perception and manual action is induced by same-direction report. Here, we found that same-direction movement stabilized the perceived motion direction, replicating a known congruency effect. For the "gear" model, congruency between perception and action is-in contrast-induced by opposite-direction report. Here, no effect of perception-action congruency was found: Perceptual congruency and cognitive model nullified each other. Hence, an observer's internal model of a machine's operation guides action-to-perception transfer.