Segmented Analysis of Eye Gaze Behaviors of Fluent and Stuttered Speech

Purpose: To measure the effect of stuttering on eye-gaze in fluent speakers while viewing video presentations of typical speakers and people who stutter (PWS) speaking because eye-gaze behaviors provide indicators of emotion and communicative integrity. Method: Sixteen fluent college-age adults, naive to stuttering, observed six 30-second audiovisual speech samples of three PWS, and three age and gender matched controls who do not stutter (PWNS). A desk-mounted eye-tracker recorded the amount of time participants spent watching four regions of interest (ROIs) in the stimulus videos of PWS and PWNS: eyes, nose, mouth, and "outside" (i.e., any gaze-point not occurring within the eyes, nose, or mouth area). Proportions of gaze-time in each ROI were the dependent variables of interest in the study. Comparisons were made between proportions of time spent in each ROI for the PWS and PWNS speaker groups, and also between fluent versus disfluent speech segments produced by the PWS. Results: Participants spent significantly more time watching the eyes (e.g., maintaining eye-contact) when viewing PWNS than PWS. They also spent significantly more time observing mouth regions of PWS. When watching the videos of PWS, participants spent significantly more time observing nose and mouth regions when speech was stuttered (PWS-S) than when the speech was fluent (PWS-F). Conclusions: Overall, the difference in eye gaze patterns across speaker-group is interpreted to indicate negative emotional responses to stuttering. Current findings align with previous research showing that stuttered speech elicits negative reactions from listeners. Specifically, stuttering behaviors avert gaze from the eyes. Gaze aversion is a clear sign of disrupted communication that is visible to PWS and may contribute to their negative reactions to their own stuttering.