The Purdue Stuttering Project

The PURDUE STUTTERING PROJECT is no longer recruiting new participants as we are in the final stages of data analyses and working on final publications describing our research.

Some History.

The project was founded in the late 1980s by Professor Anne Smith in the Department of Speech, Language, and Hearing Sciences at Purdue University. Dr. Smith received support for her research from the NIH’s National Institute on Deafness and Other Communicative Disorders for the project , "Physiological Correlates of Stuttering.” She, with many colleagues and students, completed experiments examining the physiological processes, for example patterns of speech muscle activity and movements that occur in adults when they are speaking fluently and when they experience stuttering breakdowns. Along with the results from other labs, their findings established that adults who stutter, even when they are speaking fluently, have continuously present instabilities in their speech motor systems. Surprisingly, Dr. Weber's research on brain activity during reading and listening tasks showed that adults who stutter also have unusual patterns of brain activity when they process verbal material without speaking. Thus we know that the effects of stuttering are ever present, not just at the moments when stuttering disfluencies are heard.

Research on Development of Stuttering in Young Children.

Of course, stuttering usually begins when children are 3-5 years old. So Drs. Smith and Weber (Co-Directors of the PSP) worked diligently to "translate" all of their experimental methods into "kid friendly" protocols. In the final years of the project, the PSP researchers did groundbreaking work studying the early physiological components of stuttering. For example, they showed that in preschoolers who are stuttering, there are signs that their speech motor systems are developing differently and they show atypical patterns of brain activity when they are listening to speech. However, they also found that many of these children would "catch up" and become normally fluent speakers. This work helped us to understand that stuttering is a neurodevelopmental disorder. This means that it arises when the brain does not form the typical circuits needed to develop highly stable, fluent speech production systems during later childhood and adolescence. This group also identified some clinical and physiological measures that can help predict whether a 4-5 year old child who stutters will eventually recover or persist.  Drs. Smith and Weber summarized our current understanding of the onset and development of stuttering in the 2017 article, “How Stuttering Develops: The Multifactorial Dynamic Pathways Theory.” 

The Team.

Over the years, the team of collaborators on the PSP changed and grew in many different ways. The team was always multidisciplinary. Early collaborators were biomedical engineers and exercise scientists. As the team evolved to focus on children, collaborators with expertise in child language development and social behavioral development came onboard. One very exciting development in the final years of the project was the addition of Dr. Bridget Walsh, who established a new laboratory to use functional near infrared spectroscopy (fNIRS) to record brain activity patterns during speaking. She is continuing this work at Michigan State University and directs the Developmental Speech laboratory. Dr. Weber continues her work at Purdue with a focus on stuttering and child language disorders. Dr. Smith has retired and lives in Oregon.

Speech, Language, & Hearing Sciences, Lyles-Porter Hall, 715 Clinic Drive, West Lafayette, IN 47907-2122, PH: (765) 494-3789

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