April 1, 2020

Study to explore TBI’s impact on language processing

Researchers from Vanderbilt University Medical Center and Vanderbilt University have been awarded more than $3.8 million to study the impact of traumatic brain injury (TBI) on one’s ability to process language in everyday settings.

Melissa Duff, PhD, left, and Sarah Brown-Schmidt, PhD, are studying the role of traumatic brain injury in language processing. (photo taken prior to social distancing measures)

by Kelsey Herbers

Researchers from Vanderbilt University Medical Center and Vanderbilt University have been awarded more than $3.8 million to study the impact of traumatic brain injury (TBI) on one’s ability to process language in everyday settings.

The five-year project, led by Melissa Duff, PhD, and Sarah Brown-Schmidt, PhD, suggests that current methods used to identify communication deficits in adults with TBI are too limiting, making it difficult to predict communication outcomes.

Currently, methods used to diagnose language impairments may include asking an individual to name objects, repeat sentences or follow commands. Researchers say these tasks don’t account for the flexible use of language that’s needed to carry on relevant conversations and adapt messages based on contextual cues, such as their relationship to the person with whom they’re speaking or their environment.

Many individuals with TBI can perform decontextualized tasks fine but still have trouble communicating in everyday interactions, making inappropriate or irrelevant comments in normal conversation.

“We know there is tremendous variability in communication outcomes following TBI, but we don’t yet know at the time of injury or during their rehabilitation which individuals will have chronic communication deficits that will interfere with their social, academic or vocational pursuits,” said Duff, associate professor of Hearing and Speech Sciences at VUMC. “The conventional wisdom has been that TBI does not affect basic language processing, but language processing in TBI has never been examined in the moment or in contextual tasks.”

To examine language use in context, Duff and Brown-Schmidt will track the eye gaze of individuals with TBI and their communication partner both in free-form conversation and as they talk about game pieces in a specially designed game. By tracking the individual’s eye movement, researchers can monitor how language production and comprehension unfold in real time and how the context of the game shapes language use.

The project will also test language use in group settings by having participants with TBI play games in groups where some of the individuals are familiar with the game and others are not. Previous work by Brown-Schmidt showed that when talking in a group setting, speakers without TBI were able to tailor how much information they provided based on the overall knowledge of the group. Researchers plan to extend these findings to determine if and how these processes are affected by TBI.

“This research will offer a new and more comprehensive characterization of language deficits in individuals with TBI,” said Brown-Schmidt, associate professor of Psychology and Human Development at Vanderbilt University. “This work is also a critical first step in laying the groundwork for future work developing new assessment tools for earlier identification of language deficits and to develop intervention approaches aimed at improving the communicative lives of individuals with TBI.”

According to the Centers for Disease Control and Prevention (CDC), approximately 2.8 million Americans seek care for TBI each year. Yet despite its prevalence, no significant improvements in outcomes have been documented over the last two decades.

“Communication problems that result from TBI vary from person to person, but currently available assessments often cannot identify some of the subtle language differences that exist in this population. It can be especially difficult to predict the extent of long-term problems in the early days following injury,” said Anne Marie Tharpe, PhD, chair of the Department of Hearing and Speech Sciences and associate director of the Vanderbilt Bill Wilkerson Center.

“The work by Duff and Brown-Schmidt will move us closer to the goal of improved assessment and intervention for these patients.”

This research is supported by the National Institute on Deafness and Other Communication Disorders (grant DC017926).