Direct eye gaze enhances the ventriloquism effect

The "ventriloquism effect" describes an illusory phenomenon where the perceived location of an auditory stimulus is pulled toward the location of a visual stimulus. Ventriloquists use this phenomenon to create an illusion where an inanimate puppet is perceived to speak. Ventriloquists use the expression and suppression of their own and the puppet's mouth movements as well the direction of their respective eye gaze to maximize the illusion. While the puppet's often exaggerated mouth movements have been demonstrated to enhance the ventriloquism effect, the contribution of direct eye gaze remains unknown. In Experiment 1, participants viewed an image of a person's face while hearing a temporally synchronous recording of a voice originating from different locations on the azimuthal plane. The eyes of the facial stimuli were either looking directly at participants or were closed. Participants were more likely to misperceive the location of a range of voice locations as coming from a central position when the eye gaze of the facial stimuli were directed toward them. Thus, direct gaze enhances the ventriloquist effect by attracting participants' perception of the voice locations toward the location of the face. In an exploratory analysis, we furthermore found no evidence for an other-race effect between White vs Asian listeners. In Experiment 2, we replicated the effect of direct eye gaze on the ventriloquism effect, also showing that faces per se attract perceived sound locations compared with audio-only sound localization. Showing a modulation of the ventriloquism effect by socially-salient eye gaze information thus adds to previous findings reporting top-down influences on this effect.