Gaze behavior in audiovisual speech perception: The influence of ocular fixations on the McGurk effect

We conducted three experiments in order to examine the influence of gaze behavior and fixation on audiovisual speech perception in a task that required subjects to report the speech sound they perceived during the presentation of congruent and incongruent (McGurk) audiovisual stimuli. Experiment 1 showed that the subjects' natural gaze behavior rarely involved gaze fixations beyond the oral and ocular regions of the talker's face and that these gaze fixations did not predict the likelihood of perceiving the McGurk effect. Experiments 2 and 3 showed that manipulation of the subjects' gaze fixations within the talker's face did not influence audiovisual speech perception substantially and that it was not until the gaze was displaced beyond 10 degrees - 20 degrees from…