Influence of visual attention upon sound localization

Previous studies on audio-visual interaction such as the ventriloquism effe ct have indicated cognitive (or context) factors as well as sensory (or syn chronous) factors could make the interaction. In these studies, however, vi sual attention seems to have been neglected. Thus, it has been still unknow n whether the visual attention affects the interaction or not. We investiga ted the contribution of the attention factors to the audio-visual interacti on by comparing the sound localization biases made by attentional factors a nd those by synchronous factors. Three subjects participated in the localiz ation tasks in horizontal and vertical orientations. As the results, we fou nd small influence of the attentional factors upon the interaction in the h orizontal orientation, and no influence in the vertical orientation. On the contrary, the effect of the synchronous factors was larger in the vertical orientation than in the horizontal orientation. We concluded that the visu al attention could affect the audio-visual interaction slightly, and that t he influences of the attentional factors and the perceptual factors upon th e interactions were made in the different processes.