Gaze aversion to stuttered speech: a pilot study investigating differential visual attention to stuttered and fluent speech

Aims: To compare the eye gaze responses of college students while observing and listening to fluent and severely stuttered speech samples produced by the same adult male who stutters. Methods & Procedures: Twelve normally fluent adult college students watched and listened to three 20-second audio-video clips of the face of an adult male stuttering and three 20-second clips of the same male producing fluent speech. Their pupillary movements were recorded with an eye-tracking device and mapped to specific regions of interest (that is, the eyes, the nose and the mouth of the speaker). Outcomes & Results: Participants spent 39% more time fixating on the speaker's eyes while witnessing fluent speech compared with stuttered speech. In contrast, participants averted their direct eye gaze more often and spent 45% more time fixating on the speaker's nose when witnessing stuttered speech compared with fluent speech. These relative time differences occurred as a function of the number of fixations in each area of interest. Thus, participants averted their gaze from the eyes of the speaker more frequently during the stuttered stimuli than the fluent stimuli. Conclusions & Implications: This laboratory study provides pilot data suggesting that gaze aversion is a salient response to the breakdown in communication that occurs during stuttering. This response may occur as a result of emotional, cognitive, and pragmatic factors in communication partners. Regardless of the factors contributing to the response, its primary importance may be that gaze aversion is a visible communication partner signal informing the person stuttering that something is amiss in the interaction and hence, may contribute to inducing negative emotions in the persons stuttering, via engagement of the mirror neuron system. We suggest that witnessing and interpreting communication partner responses to stuttering may play a role when a person who stutters engages in future interactions, perhaps contributing to the development of covert strategies to hide stuttering.