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Dissertation defense for Bradley White

  • Date: July 16, 2019
  • Time: 10:00 AM
  • Location: College Hall Lyceum (room 318)
Description

To:      Students, Faculty and Staff

From:  Gaurav Mathur, Ph.D., Dean of the Graduate School

Re:       Dissertation Defense for Bradley White

It is my pleasure to announce that Bradley E. White, a candidate in the Ph.D. in Educational Neuroscience (PEN) Program, will defend his dissertation on “The role of auditory experience in the neurocognitive systems for everyday and effortful listening” on Tuesday, July 16 at 10 a.m. in College Hall Lyceum (room 318). The first forty minutes of the dissertation defense are open to the Gallaudet community.

Current models of auditory cognition suggest that cognitive resources for processing challenging acoustic and linguistic information are limited, creating a trade-off between effort and comprehension. Indeed, everyday listening frequently occurs under a wide range of inescapable suboptimal and adverse conditions, challenges which are exacerbated by reduced hearing acuity and the use of imperfect hearing amplification and prosthetic devices. Using an assessment battery of hearing, listening, health status, intelligence, and language in combination with optical neuroimaging during a plausibility judgment task, Mr. White’s study assesses: (a) the effects of early-life sensitive periods on the neurocognitive mechanisms of everyday and effortful speech and language processing in response to early, life-long exposure to undegraded and acoustically-degraded speech and (b) the strength and nature of the relationships between physiological changes in hemodynamic activity in brain regions mediating effortful online speech and language processing and behavioral changes in task performance and perceived levels of expended mental effort for different listening conditions and cognitive demands. To advance these areas of scientific inquiry, he tested two competing hypotheses, the (a) adaptive listening and (b) effortful listening hypotheses. Using a combination of behavioral and neuroimaging analyses, he observed support for the effortful listening hypothesis. Findings reveal modulated online processing of everyday and effortful speech and language in hearing aid and cochlear implant users and suggests: (a) greater initial and persistent contributions of cognitive executive functions than listeners with typical hearing, (b) modulated selectivity for effortful speech and language processing in the brain, and (c) stronger brain-behavior correlations dissimilar to listeners with typical hearing that indicate the use of different attentional mechanisms. Ultimately, this work advances several scientific and societal questions regarding the role of deafness mediated by hearing technologies in certain cognitive functions, specifically online speech and language processing. These advancements could improve overall spoken language outcomes in those with hearing loss.

 

The members of Mr. White’s dissertation committee are Dr. Clifton Langdon, Ph.D. Program in Educational Neuroscience, chair of the dissertation committee; Dr. Lorna Quandt, Ph.D. Program in Educational Neuroscience; Dr. Poorna Kushalnagar, Department of Psychology; and Professor Josef Rauschecker, Department of Neuroscience, Georgetown University Medical Center.

Since joining the Ph.D. in Educational Neuroscience Program in Fall 2015, Mr. White has been a Doctoral Research Fellow in Dr. Clifton Langdon’s Language and Educational Neuroscience Laboratory and a Student Scholar in the National Science Foundation’s Science of Learning Center on Visual Language and Visual Learning. Broadly speaking, Mr. White’s research program focuses on the neurocognitive, neurobiological, and neurochemical systems for everyday and effortful listening. This work advances our understanding of language perception and comprehension in children and adults, especially those who use hearing aids and cochlear implants. He is certified in magnetic resonance imaging (MRI) and near-infrared spectroscopy (NIRS), has first-authored more than 12 national and international peer-reviewed scientific presentations, has published award-winning research-based translational products for professionals and families with young d/Deaf and hard-of-hearing children, and has released more than 5 software and coding tools for neuroimaging analysis. Mr. White’s doctoral training and dissertation research were funded in part by a Florence R. Foerderer Fellowship, the Office of Research Support and International Affairs at Gallaudet University, and fellowship support from a National Science Foundation grant to the Science of Learning Center on Visual Language and Visual Learning.

Please join me in extending best wishes to Bradley White for his dissertation defense. 

Posted by Elizabeth Gibbons | Posted June 28, 2019 at 1:30 PM

Gallaudet

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Gallaudet

800 Florida Avenue NE
Washington, DC 20002