Research Projects
Our primary research focus is in the onset and development of stuttering in early childhood. Currently, we are conducting two studies to achieve our research goals.

Physiological Correlates of Stuttering
This research project is designed to investigate the movements (for example. jaw and lips) produced during speech by 4-6 year-old children who do and do not stutter, and relate them to how speech and language are processed. Our hope is that this study will further our understanding of the neural processes underlying the organization of movement in speech, and how they relate to the neural systems involved in language processing. This study will provide baseline information that may help us to understand how language processing and speech movements co-develop in children, and how children with speech and language disorders differ from normal speakers.

The children who participate visit our laboratory once each year over a three year period. Each visit consists of six sessions that are scheduled over a period of several weeks. During the first session of each visit, a series of standardized speech, language, and hearing tests are administered to ensure that each child is within the normal range for his/her chronological age. During the second session of each visit, the child participates in three tasks. The first involves the tracking of hand movements during a series of clapping tasks. The second involves the tracking of jaw and lip movement and muscle activity while the child says a series of words and sentences. The third task involves recording of brain activity while the child listens to sounds, words, sentences and stories, and is asked to make simple manual or verbal responses. The recording of brain activity is accomplished through the use of a special cap that has sensors sewn into it. All of the sensing devises used in this study are non-invasive (in other words, they are applied to the surface of the skin, or in the case of those used to record brain activity, the sensors are sewn into a cap that the child wears on his/her head) and are non-intrusive (i.e. they in no way interfere with talking or movement).

This study is supported by the National Institute on Deafness and Other Communication Disorders (R01# DC000559, "Physiological Correlates of Stuttering"). Iowa works in collaboration with Purdue University on this research.

Subtypes and Risk Factors in Childhood Stuttering
Presently, we are in the fourth year of a National Institutes of Deafness and Other Communicative Disorders (NIDCD) grant entitled "Subtypes and Risk Factors in Childhood Stuttering" (R01# DC05210). The general objective of this multi-site (University of Illinois, Northern Illinois University, and University of Wisconsin-Milwaukee) project is to study variations in the onset and subsequent developmental course of stuttering in children under age six. We are interested in finding out why and how some children develop more chronic and severe symptoms shortly after onset, while others recover without treatment. Specific goals are to:

• Determine variations in onset of stuttering and how they might relate to the future course of the problem
  
• Obtain measures of both the magnitude and timing of natural recovery
  
• Identify key factors that influence recovery, as well as those that may predict chronic stuttering
  
• Isolate subtypes of stuttering

This project involves the recording and testing of young children close to the onset of stuttering, as reported by parents or primary caregivers. Testing includes speech, language, hearing, motor skills, temperament and perception of self. In addition, parents or caregivers will be asked to provide background information regarding the child's overall development and relevant family history. After the initial testing we will provide follow-ups every six months for a period of several years. This close monitoring will allow us to document the course of either recovery or persistence, and the factors that are likely predictors of each.

The following PowerPoint presentations by Dr. Zebrowski are available in ppt format:

Why Stuttering Therapy Works: The “Common Factors” along with the complete reference list.

Beyond Technique: What Makes Therapy Work? and reference list from the 2007 Council on Academic Programs in Communication Sciences and Disorders (CAPCSD) meeting.

Friends 2007 Convention in St. Louis, given on July 6, 2007.

2007 SID-IV Conference presentation.

2007 ASHA Poster: Phonetically Governed Voicing Onset and Offset in Children Who Stutter

Coping with Stuttering from the 2007 Friends Day at The University of Iowa

Forming Alliances, also from the 2007 Friends Day at UI

2008 National Stuttering Association meeting: PowerPoint presentation | Reference list (pdf)

Purdue University Crossroads Conference (10/08): PowerPoint presentation | Reference list (pdf)

ASHA Meeting (November 2008 in Chicago): PowerPoint presentation | Reference list (doc)

(back to top)