The Department of Communication Sciences and Disorders at the University of Iowa is one of the oldest in the United States. Although originally developed under Psychology around the 1930s, Speech Pathology and Audiology became an independent department in 1956, and moved into its current location in the Wendell Johnson Speech & Hearing building in 1967. This year, we became the Department of Communication Sciences and Disorders. The department has been ranked in the top 2 in the nation by US News and World Report magazine for several years. The Wendell Johnson Speech and Hearing Clinic has a history of excellence in the quality of clinical services provided to individuals with communication disorders and in the quality of clinical education offered to graduate students in speech pathology and audiology. Today the goal at Wendell Johnson Speech and Hearing Center is to build a future worthy of the past. Assessment and therapy are provided by graduate student-clinicians under the direct supervision of certified and licensed speech-language pathologists and audiologists.

Active research programs exist at The University of Iowa in all major areas of speech and hearing. Individual laboratories are maintained in the Wendell Johnson Speech and Hearing Center for the study of auditory physiology, auditory rehabilitation, clinical experimental and medical audiology, language disorders and intervention, neurology of speech and language, psychoacoustics, psycholinguistics, speech physiology, stuttering, and voice acoustics and biomechanics.

Today I will be highlighting four labs focusing on research in speech and language processes: The Neurogenic Language Disorders Lab, the Stuttering Research Lab, the Grammar Acquisition Lab and the Laryngeal Biomechanics and Cell Biology Lab.

The first lab I will describe is the Neurogenic Language Disorders Lab. This lab is run by Dr. Jean Gordon. The focus of her lab is to investigate the processes of language production, particularly word retrieval, and how they can be disrupted by aging and acquired language disorders, especially aphasia. Aphasia is a language impairment, typically caused by a left hemisphere stroke, that affects the use of language in all modalities—speaking, listening, reading and writing. Word retrieval is especially susceptible to both aging and brain damage. She is currently investigating the factors which influence word retrieval (e.g. frequency, length, number of competitors in the lexicon) in adults without any impairment, and in people with aphasia. Both single-word production and single-word recognition are being assessed. In addition, she uses connected speech tasks to examine the effects of context on word retrieval in individuals with fluent and non-fluent aphasia. She has also tested different therapy approaches to improve word retrieval in people with aphasia. In the neurogenics clinic, she provides treatment for people with acquired neurogenic speech-language disorders, in both one-on-one and group settings.

Word retrieval problems generally fit into one of two categories: anomia and agrammatism. In anomia, the patient is able to use the function structures of speech, but has a difficult time expressing specific content, “I went to the place to get some, you know, stuff to eat.” Conversely, agrammatic patients are able to express specific content words, but have more difficulty using the appropriate structures of speech, “I go… in store… uh, food… milk and bread and… eat it.”

Dr. Gordon refers to Connectionist models in her research on aphasia. Here you see different layers corresponding to semantic information, lexical information and phonological information. Hearing the sequence /k/ /æ/ /t/ would activate the lexical representation cat, and the semantic correlates “animal”, “pet”, “meows”. Conversely, if one wishes to discuss animal that is a pet, the lexical representation dog would activate, and then the sequence /d/ /ɑ/ /g/ would be pronounced. If this system degrades due to injury or age, then unintended speech outcomes may occur if misconnections take place.

Dr. Gordon has found that, in people with aphasia, a word that has more phonological neighbors is easier to produce, but more difficult to recognize.

Dr. Gordon also explored two methods of therapy for people with aphasia. She compared outcomes for those persons receiving semantic feature analysis therapy and those who received contextual approach therapy. Semantic Feature Analysis involves asking the client to list semantic features (e.g. What category does it belong to? What’s it used for? Where would you find it? What does it look like?). The contextual approach involved telling a story to the client, using the target word several times, then asking the client to retell the story; So it aims to train the target more implicitly, in a more natural language context. She found that both methods were able to increase word retrieval ability in her subject populations!

Dr. Patricia Zebrowski, who is with us here today, is head of the Stuttering Research Lab at 爱大. Stuttering research lab is probably the oldest in the department of ComSci. In fact, the SHC is named after an important stuttering researcher, Wendell Johnson. The UI Stuttering Lab has been collaborating with Purdue University in Indiana on two projects: one to characterize the subtypes of stuttering and their associated risk factors; the other to examine physiological correlates of stuttering.

Stuttering occurs in 1-5% of the population, and spontaneously recovers in about 70% of those people. Who is at risk for stuttering is still somewhat of a mystery. Finding a single risk factor that predicts stuttering has been rather unsuccessful. Trish’s lab is trying to discover what groups of risk factors may predict certain subgroups of people who stutter – including temperament, language, and speech motor.

Her lab is also looking at motor output characteristics in children who stutter. She is measuring hand movement and lower lip movement as well as recording brain activity as children listen to stimuli. Because this data is being analyzed at Purdue, we do not know anything yet. Stay tuned.

Let’s move now to the Grammar Acquisition Lab. This lab is run by a new faculty member, Dr. Amanda Owen. As you can see, she also works with children. Dr. Owen examines the processes that support grammar acquisition and uses that information to understand individual differences in grammar production and comprehension. Dr. Owen believes that children learn grammar similarly to the way that they learn words, through multiple exposures to similar structures. Children tend to anchor their grammar production around a common verb with broad meaning. For example, in English, young children commonly use the prototype verb “go”. The grammar structure that is invoked by the verb ‘go’ is Subject-Verb-Locative-Object, as in “He is going to school.” When the structure is stable, children then may begin using more specific verbs that follow the same grammar construction, such as “He is walking to school.” A study recently performed by Dr. Owen and her doctoral student Vicki Samelson are looking at whether there is a ratio of prototype verb to extension verb exposure that helped children learn a new grammatical structure. Typically developing children did best with one strong verb and then some exposure to extension verbs. This may be evidence for the child that the structure is non-idiomatic. They are still collecting data on children with language impairment.

Some of you may not be familiar with language impairment. The profile differs across languages, but some patterns are seen across cultures. Often their first word is not spoken until 18 months of age. They do not achieve the 2-word level of speech until between 2 ½ to 3 years old. They also show deficits into school age, especially with the comprehension and production of complex grammatical structures. Some research on Chinese speaking children with language impairment shows special difficulty with verb temporal complements such as 我在看书 or 我看着书. Dr. Owen also looked at how children with language impairment perform on complex and compound sentences with transitive or intransitive second clauses. She found that children with SLI were more accurate on coordinate clauses than subordinate clauses. She also found that children with SLI had a more difficulty time with transitive verbs than normally developing children, but performed similarly on intransitive verbs. This is evidence that complex grammatical structure is more taxing for these children than sentence length.

The final lab I will be discussing today is the Laryngeal Molecular and Cell Biology Lab and it’s sister, the Laryngeal Biomechanics Lab. This lab is headed by Dr. Ingo Titze with much assistance from his research assistant, Dr. Sarah Klemuk. The mission of these researchers is to understand the molecular underpinnings of laryngeal development and response to environmental vibrational stresses; connecting the microscopic to the macroscopic. Most research is done on the vocal folds, as these are subjected to extreme amounts of vibration in humans, as energy from the airstream is exchanged to the vocal folds. In order to study these tissues, the researchers have created a bioreactor. This machine keeps tissue alive while at the same time subjecting it to stresses such as vibration or shearing. The researchers have found that with increased frequency of vibration, physical changes in vocal fold tissue take place, causing an increase in elasticity and viscosity. Dissection demonstrated that the fibers become less organized. Also, molecular changes were noted as well. This slide shows the effect of strain without and with vibration on vocal fold molecules and genes. Future directions of this lab include improving the design of the bioreactor to extend the frequency range, the types of tissue geometries, the duration of testing, and the complexity of vibration.

Thank you for listening to my talk today. I may not be able to answer your questions, but I would be happy to try, as well as to give you any contact information for the labs represented here.