Date of Award
Master of Arts
Peter Flipsen, Mark Hedrick
The present study investigated the effects of viewing audio-visual presentations of stuttered relative to fluent speech samples on the ocular reactions of participants. Ten adults, 5 males and 5 females, aged 18-55 who had a negative history of any speech, language and hearing disorders participated in the study. Participants were shown three 30 second audio-visual recordings of stuttered speech, and three 30 second audio-visual recordings of fluent speech, with a three second break (black screen) between the presentation of each video.
All three individuals who stutter were rated as ‘severe’ (SSI-3, Riley, 1994), exhibiting high levels of struggle filled with overt stuttering behaviors such as repetitions, prolongations and silent postural fixations on speech sounds, in addition to tension-filled secondary behaviors such as head jerks, lip protrusion, and facial grimaces. During stuttered and fluent conditions, ocular behaviors of the viewers including pupillary movement, fixation time, eye-blink, and relative changes in pupil diameter were recorded using the Arrington ViewPoint Eye-Tracker infrared camera and the system’s data analysis software (e.g., Wong & Cronin-Colomb & Neargarder, 2005) via a 2.8GHz Dell Optiplex GX270 computer. For all ocular measures except fixation time, there were significant (p<.05) differences for stuttered relative to fluent speech. There was an increase in the number of pupillary movements, blinks, and relative change in pupil diameter and a decrease in time fixated when viewing stuttered relative to fluent speech samples. While not significant, participants fixated or directed their attention for less time during stuttered than fluent conditions, indicating decreased attention overall during stuttered speech samples. Increases in eye-blink data and pupil-dilation data were also significant. Because both eye-blink, as a measure of the startle reflex, and pupil-dilation are resistant to voluntary control or are completely under the control of the autonomic nervous system, significant increases in both for stuttered relative to fluent speech indicate a visceral reaction to stuttering.
Bowers IV, Andrew Lee, "Eye-to-face Gaze in Stuttered Versus Fluent Speech. " Master's Thesis, University of Tennessee, 2007.