New windows on the onset of stuttering

By Anne Smith, Ph.D.,
Purdue University

In July of this year, I was honored to be a keynote speaker at the?ÿmeeting of International Fluency Association in the wonderful city of?ÿDublin, Ireland. In my talk, ƒ??Physiological Indices of Speech and?ÿLanguage Processes: New Windows on the Onset of Stuttering in Young?ÿChildren,ƒ?? I reviewed some of the accomplishments of the Purdue?ÿStuttering Project and outlined our ongoing research studies. Here?ÿare some of the highlights from that talk:

First, to let you know our point of view about stuttering ƒ?? Despite?ÿthe diversity of the disorder in different people who stutter, all?ÿindividuals who stutter exhibit breakdowns in the motor processes?ÿnecessary for speaking. The factors that influence these breakdowns?ÿin speech are complex.?ÿ We have proposed that a complete model of?ÿstuttering must incorporate motor, linguistic, cognitive,?ÿpsychosocial, and genetic factors, and that the model must explain?ÿhow these factors interact during childhood to produce the?ÿdisruptions in speech that makes one a person who stutters.

What we know from studies of adults who stutter ƒ?? Much of our?ÿearlier work on the Purdue Stuttering Project was focused on adults?ÿwho stutter.?ÿ These studies were essential to establish what the?ÿphysiological bases of the disorder are in individuals with chronic?ÿstuttering. Our findings, in addition to those from many other?ÿresearch groups, mapped the differences in speech movement and muscle?ÿactivity that occur during disfluent speech in the face, voice, and?ÿbreathing areas. We also looked at language processing in adults who?ÿstutter when they are not speaking. One surprising finding was that?ÿwhen adults who stutter are reading, their brains are processing some?ÿaspects of language very differently compared to control participants?ÿwho do not stutter.

What we are doing now ƒ?? We all know that stuttering starts in very?ÿyoung children. Over the past five years, we have been developing?ÿways to gather the same physiological measures from young children.?ÿBy adapting our methods and making them kid friendly, we have been?ÿable to test children as young as four. In the current phase of the?ÿPurdue Stuttering Project, we are bringing in a group of 50 children?ÿwho stutter ages 4-5 years. We plan to test these children and a?ÿmatched group of non-stuttering children over a five-year period?ÿ(please note that the NIH, because of budget restraints, only gave us?ÿ3 years of funding , and we hope to get them to support the later?ÿyears!).

We know from earlier research that approximately half of the?ÿchildren who are stuttering at 4-5 years, will persist and have a?ÿchronic stuttering problem, while approximately half of these?ÿchildren will recover. By using new experimental windows on how young?ÿbrains are developing speech, we hope to develop methods by which we?ÿcan predict which children are likely to have a chronic stuttering?ÿproblem. In addition we will attempt to determine the factors that?ÿplay a critical role in the development of chronic stuttering so that?ÿbetter therapies for young children will be available.

Thanks to the National Institute on Deafness and Other Communicative?ÿDisorders and to the Malcolm Fraser Foundation for their support of?ÿthe Purdue Stuttering Project, which is co-directed by Anne Smith,?ÿPh.D., and Christine Weber-Fox, Ph.D. It has been exploring new?ÿfrontiers in the physiology of stuttering since 1989.?ÿ