Spatial coincidence modulates the Colavita visual dominance effect.

The Colavita visual dominance effect refers to the phenomenon whereby participants presented with auditory, visual, or audiovisual stimuli in a speeded response task sometimes fail to respond to the auditory component of the bimodal targets. We conducted an experiment on the Colavita effect in which the auditory and visual components of the bimodal targets were presented from either the same or different positions (sides) at one of two eccentricities (13 degrees or 26 degrees ). Participants were presented with auditory, visual, and bimodal stimuli to which they had to respond by pressing an auditory response key, a visual response key, or both response keys, respectively. On bimodal trials, participants failed to respond to the auditory stimulus significantly more often than they failed to respond to the visual stimulus, resulting in a significant Colavita visual dominance effect. The Colavita effect was significantly larger when the stimuli were presented from the same position than when they were presented from different positions. These results provide the first empirical evidence that the Colavita effect is modulated by the spatial coincidence of the auditory and visual stimuli.