Date of Completion

Spring 5-1-2020

Thesis Advisor(s)

Letitia Naigles

Honors Major

Biological Sciences


The goal of this project was to observe relationships between auditory brainstem response (ABR) and sentence comprehension in college students, answering the question: does complex sentence comprehension show a link with brainstem processing? This project addresses the need to study subcortical contributions to language comprehension in order to fully understand language processing, as most studies revolve around the cortex. Sentence comprehension was tested through completion of a task in which participants hear a sentence before being prompted to choose the correct match between two pictures. Twenty total sentences of four variously-complex types were randomly presented. Participants were monolingual English-speaking adults between ages 18 to 27 with normal hearing. They completed a hearing screening, the timed-sentence comprehension task, and a standardized vocabulary test. ABRs of each participant were recorded as they heard one-syllable sounds. Different components were analyzed to assess participants’ wave repeatability in response to hearing the same sound and the ability to differentiate sounds. These measures were statistically tested along with participants’ accuracy and reaction times in the timed-sentence comprehension task for correlations. Easier sentences resulted in higher scores and faster reaction times, with reaction time related to how well the brainstem processes different complex speech stimuli. By observing and quantifying individual variation, the findings demonstrate involvement of the brainstem in neural language encoding. This project informs future endeavors of the relationships between ABR measures and complex sentence comprehension. Moving forward, researchers can use subcortical assessments to study various aspects of language in different populations.