Sensory specificity of apparent motion.

Previous reports of intermodal apparent motion claim that the various senses contribute to or are under the guidance of a single synthesizing or organizing system, a common sense, and that under proper circumstances the separate heteromodal stimuli may be combined into a novel perceptual object. Our first experiment suggests that the term intermodal apparent motion has been misapplied in the past to one of the many idiosyncratic interpretations to which relatively meaningless patterns of heteromodal stimulation lend themselves. In our second experiment, we found that a properly timed visual stimulus can facilitate the perception of auditory apparent motion without its peculiarly auditory qualities of the moving percept. We find no evidence for a common or suprasensory organizing principle that integrates the separate visual and auditory stimuli.