Stuttering is a disorder of speech with a prevalence estimated to be 1% of the world's population. It is often a significant communicative problem for the individual, limiting educational and employment opportunities and social and psychological adjustment. The precise etiology of stuttering is unknown, and treatment strategies and outcomes are highly variable. A major impediment to understanding the etiology of stuttering and to the development of successful therapeutic techniques is the lack of understanding of the physiological bases of the disorder, especially as the disorder emerges in the pre-school years. Stuttering manifests itself as a breakdown in speech motor processes. The complex factors known to affect the occurrence of stuttering must ultimately have an effect on the physiological events necessary for the production of speech. There has been significant progress in understanding the physiological bases of stuttering in adults. Stuttering, however, is a developmental disorder with an average age of onset of 3-years. There is almost no work on the physiology of stuttering in young children to help us understand the developmental physiology and the etiology of the disorder. In our theoretical framework on stuttering, we posit that motor, linguistic, cognitive, psychosocial, and genetic factors play a role in the onset and development of stuttering. Further it seems likely that the influence of these factors changes over the lifespan of the individual who stutters. We elect to focus in this project primarily on motor and linguistic factors in preschool children who are stuttering and their normally fluent peers. We hypothesize that stuttering emerges when a child fails to acquire stable motor control and coordination processes for speech, thus making him or her vulnerable to breakdown in the face of increased processing demands. We test the hypothesis that children who stutter lag their normally fluent peers in developing speech motor control and coordination processes. Furthermore, we assess whether the speech motor systems of children who stutter are exceptionally sensitive to increased linguistic processing demands. We seek to determine if language processing differences detected in the brain activity of adults who stutter are also evident in the early years of stuttering. By employing a longitudinal experimental design, we can determine whether a set of physiological measures related to language and motor functions can discriminate children who will persist in stuttering from those who will recover.

Public Health Relevance

At present, we have no means to predict which preschool children who are stuttering (5% of the preschool population) will develop a chronic stuttering problem and who will recover. Stuttering is not a life-threatening disorder, but it is a life-altering disorder, and educational achievement, psychosocial development, and employment opportunities are often negatively affected in the1% of Americans who persist in stuttering into adulthood. Our goal is to use physiological measures to develop a set of tests that can predict which preschool children who are stuttering are likely to develop a chronic problem, so that early and more successful interventions for stuttering can be developed.

National Institute of Health (NIH)
National Institute on Deafness and Other Communication Disorders (NIDCD)
Research Project (R01)
Project #
Application #
Study Section
Motor Function, Speech and Rehabilitation Study Section (MFSR)
Program Officer
Shekim, Lana O
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Purdue University
Other Health Professions
Schools of Arts and Sciences
West Lafayette
United States
Zip Code
Usler, Evan; Smith, Anne; Weber, Christine (2017) A Lag in Speech Motor Coordination During Sentence Production Is Associated With Stuttering Persistence in Young Children. J Speech Lang Hear Res 60:51-61
Hilger, Allison I; Zelaznik, Howard; Smith, Anne (2016) Evidence That Bimanual Motor Timing Performance Is Not a Significant Factor in Developmental Stuttering. J Speech Lang Hear Res 59:674-85
Smith, Anne; Weber, Christine (2016) Childhood Stuttering: Where Are We and Where Are We Going? Semin Speech Lang 37:291-297
Walsh, Bridget; Mettel, Kathleen Marie; Smith, Anne (2015) Speech motor planning and execution deficits in early childhood stuttering. J Neurodev Disord 7:27
Usler, Evan; Weber-Fox, Christine (2015) Neurodevelopment for syntactic processing distinguishes childhood stuttering recovery versus persistence. J Neurodev Disord 7:4
Mohan, Ranjini; Weber, Christine (2015) Neural systems mediating processing of sound units of language distinguish recovery versus persistence in stuttering. J Neurodev Disord 7:28
Tumanova, Victoria; Zebrowski, Patricia M; Goodman, Shawn S et al. (2015) Motor practice effects and sensorimotor integration in adults who stutter: Evidence from visuomotor tracking performance. J Fluency Disord 45:52-72
Arnold, Hayley S; MacPherson, Megan K; Smith, Anne (2014) Autonomic correlates of speech versus nonspeech tasks in children and adults. J Speech Lang Hear Res 57:1296-307
Spencer, Caroline; Weber-Fox, Christine (2014) Preschool speech articulation and nonword repetition abilities may help predict eventual recovery or persistence of stuttering. J Fluency Disord 41:32-46
MacPherson, Megan K; Smith, Anne (2013) Influences of sentence length and syntactic complexity on the speech motor control of children who stutter. J Speech Lang Hear Res 56:89-102

Showing the most recent 10 out of 55 publications