Dr. Mandy Maguire has an article slated for publication in the journal Brain and Cognition which provides a clearer understanding of how response inhibition develops in children.
Maguire, an assistant professor in the School of Behavioral and Brain Sciences, investigates child development. She is interested in how the inhibitory process differs as tasks become more difficult because inhibition is necessary in many higher order cognitive tasks throughout childhood.
For this study, she monitored the behaviors and brain responses of children in two groups—7 to 8 year olds and 10 to 11 year olds—in three fast tasks where children had to press a button 80% of the time and inhibit a button press response 20% of the time. The tasks differed in difficulty.
By comparing across the three tasks she found that although the two groups had similar reaction times and error rates, the brain responses showed that they were using different strategies. Younger children were focused on when to press a button, but older children were using an adult-like strategy of looking for when not to press the button.
"The results are important to our understanding of the developmental changes in inhibition that occur in middle-childhood or the ages of 6 to 11," Maguire said. "This may be of particular interest in studying children with inhibitory deficits such as attention-deficit disorder."
Dr. William Katz, a professor in the School of Behavioral and Brain Sciences, is the lead author in a study on foreign accent syndrome (FAS), a rare disorder characterized by the emergency of a perceived foreign accent following brain damage.
In this case study, researchers obtained functional magnetic resonance images (fMRI) of the brain during a speech task for an American English-speaking patient who presented with FAS without a known cause and was thought to sound "Swedish" or "Eastern European." Katz and his team used fMRI during a picture-naming task designed to broadly engage the speech motor network. The results suggested substantial brain reorganization for speech motor control.
Testing of more patients who present with similar characteristics will be needed in order to better understand the neural bases of this disorder, both for patients of unknown etiology and for individuals who acquire FAS as the result of stroke or traumatic brain injury. This case study is scheduled to be published in the journal Neurocase.
Article: "Neural Bases of the Foreign Accent Syndrome: A Functional Magnetic Resonance Imaging Case Study"
Dr. Noah Sasson, an assistant professor in the School of Brain and Behavioral Sciences, is the lead author of an article detailing the benefits of comparing autism and schizophrenia for revealing mechanisms of social cognitive impairment.
The article, published in the June print edition of the Journal of Neurodevelopmental Disorders, argues that direct comparison of social cognitive impairment can highlight shared and divergent mechanisms underlying pathways to social dysfunction. The process may provide significant clinical benefit by informing the development of tailored treatment efforts.
While autism and schizophrenia share a long history of diagnostic confusion because of their overlap in social abnormalities, Dr. Sasson writes that “the goal of direct comparisons is not to conflate once again, but rather to reveal distinctions that illuminate disorder-specific mechanisms and pathways that contribute to social cognitive impairment.”
Dr. Sasson is currently conducting additional studies at the Callier Center that examine social cognition in adults with autism and adults with schizophrenia.
Article: "The benefit of directly comparing autism and schizophrenia for revealing mechanisms of social cognitive impairment"
Dr. Christine Dollaghan is the lead author in one of the first meta-analysis studies to examine the accuracy of tests currently being used to diagnose language impairments in the large and growing number of bilingual Spanish-English children in the U.S. The study, currently in press, can be accessed online in the Journal of Speech, Language, and Hearing Research. Dollaghan co-authored the study withUT Dallas graduate student Elizabeth Horner.
"Children with language impairments have an increased risk of reading and academic difficulties, so it's important to diagnose them as early as possible," Dr. Dollaghan said.
Dollaghan, a professor in the School of Behavioral and Brain Sciences, and Horner found that evidence on accuracy could be located in 17 measures of language skill; ranging from standardized tests to professional observations to parent questionnaires.
Although no measure was found to be definitive for diagnosing language impairments in this population, the majority yielded suggestive results. The study concluded with several suggestions for strengthening future research on diagnostic accuracy.
Article: "Bilingual Language Assessment: A Meta-analysis of Diagnostic Accuracy"
Dr. Emily Tobey, professor and Nelle C. Johnston Chair in the School of Behavioral and Brain Sciences, is the author of several studies and the co-author of an editorial about the long-term outcomes of cochlear implantation in early childhood. The studies are all featured in a special peer-reviewed supplement of Ear and Hearing, the official journal of the American Auditory Society.
Tobey is the lead author in a study in the special issue titled "Factors Influencing Speech Production in Elementary and High School-Aged Cochlear Implant Users." UT Dallas adjunct professor Dr. Ann Geers and graduate students Madhu Sundarrajan and Sujin Shin also are co-authors on the study.
Tobey and her colleagues evaluated the changes in speech eligibility in 110 adolescent users of cochlear implants who were first assessed in elementary school and later in high school and examined factors influencing speech intelligibility performance.
They found that speech intelligibility continued to improve from elementary through the high school years. Speech intelligibility also was strongly associated with exposure to environments where speaking and listening were included as integral pieces of the therapeutic regime.
Article: "Factors Influencing Speech Production in Elementary and High School-Aged Cochlear Implant Users"
Dr. Anne van Kleeck and her colleagues Dr. Alissa Lange and doctoral student Amy Louise Schwarz have a study in press examining the influence of race (African American and European American) and maternal education level on children's retells of a story that is widely used clinically and in research for determining children's language abilities.
By randomly drawing very small ranges of maternal education from a sample of 1305 children, the researchers were able to far more carefully control the level maternal education than has been accomplished in previous research.
Van Kleeck, professor in the School of Behavioral and Brain Sciences, and her colleagues found that there were systematic effects of maternal education on children's performance on all four test subscores, while African American children performed significantly more poorly than European American children on just one subscore. That one subscore, however, is the one most widely used in research and clinical practice.
The results indicate that using this standardized, norm-referenced story retell assessment will likely over-identify children from low socioeconomic backgrounds and those who are African American as having language impairments. The study will be published in the fall in the Journal of Speech, Language, and Hearing Research.
Article: "The Effects of Race and Maternal Education Level on Children's Retells of the Renfrew Bus Story – North American Edition"
