Résumé
Perception of orientation is fundamental for an adequate control of behavior. In this contribution we argue that supra-postural aiming action requires actors to simultaneously control their orientation relative to the environment and relative to the target object. The visual-frame effect consists of an alteration of the judged vertical when an observer is placed in a tilted room (on average, 6° in the direction of tilt). A common explanation of this effect has incriminated the body slant induced by the tilted frame. Traditional theories have posited that the perception of orientation should result from integrating multiple ambiguous cues or frames of reference. In fact, the above-reported results lend support to J. J. Gibson’s contention that the natural co-variation of visual, vestibular, and somatosensory sources of information tells us about our orientation in the world.