Audiovisual short-term influences and aftereffects in motion: examination across three sets of directional pairings.

The study of cross-modal influences in perception, particularly between the auditory and visual modalities, has been intensified recently. This paper reports on a comprehensive study of auditory-visual cross-modal influences in motion, including motion aftereffects (MAE). We examined both auditory influences on visual perception and vice versa. Visual motion interactions were examined using three directional pairings or configurations: along the horizontal, vertical, and depth axes. In Experiment 1 we assessed how the simultaneous presence of a strong motion signal in one modality affected the perception of motion in the other modality. To investigate further whether such influences have long-term effects, we tested whether adaptation in one modality alone could produce cross-modal MAEs in Experiment 2. Overall, the pattern of results was similar across all directional pairings, with the strongest cross-modal influences observed in motion along the horizontal axis; this is likely due to the greater co-localization of the two stimuli in this configuration. Although both auditory and visual stimuli affected the other modality when presented simultaneously, significant cross-modally induced aftereffects could only be produced using visual stimuli. However, we did observe vertical visual MAE following adaptation to auditory spectral motion. These results are discussed in terms of current psychophysical and neurophysiological findings concerning the way in which auditory-visual signals are processed.