Face Viewing Behavior Predicts Multisensory Gain During Speech Perception

During face viewing, some individuals prefer to fixate the mouth while others fixate the eyes. Individuals who have a history of mouth fixation might have stronger associations between visual and auditory speech, resulting in improved comprehension. First, we measured eye movements during face-viewing and observed high interindividual variability in mouth fixation time. Next, we measured eye movements and comprehension during perception of noisy auditory speech with or without visual speech. When visual speech was present, participants primarily fixated the mouth, but derived substantial benefit compared to noisy auditory speech with high interindividual variability. The benefit of visual speech was predicted by the eye movements made during the initial face-viewing task, but not by eye movements during the noisy speech task. These findings suggest a link between eye movements during face viewing and audiovisual speech perception and suggest that individual histories of visual exposure shape abilities across cognitive domains.