The role of attention in eliciting a musically induced visual motion aftereffect.

Previous studies have reported visual motion aftereffects (MAEs) following prolonged exposure to auditory stimuli depicting motion, such as ascending or descending musical scales. The role of attention in modulating these cross-modal MAEs, however, remains unclear. The present study manipulated the level of attention directed to musical scales depicting motion and assessed subsequent changes in MAE strength. In Experiment 1, participants either responded to an occasional secondary auditory stimulus presented concurrently with the musical scales (diverted-attention condition) or focused on the scales (control condition). In Experiment 2 we increased the attentional load of the task by having participants perform an auditory 1-back task in one ear, while the musical scales were played in the other. Visual motion perception in both experiments was assessed via random dot kinematograms (RDKs) varying in motion coherence. Results from Experiment 1 replicated prior work, in that extended listening to ascending scales resulted in a greater likelihood of judging RDK motion as descending, in line with the MAE. In contrast, the MAE was eliminated in Experiment 2. These results were internally replicated using an in-lab, within-participant design (Experiment 3). These results suggest that attention is necessary in eliciting an auditory-induced visual MAE.