lexical decay rate in young adults with specific language impairment

Open Access
- Author:
- Watkins, Holly Spain
- Area of Honors:
- Communication Sciences and Disorders
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Dr. Carol Anne Miller, Thesis Supervisor
Dr. Carol Anne Miller, Thesis Honors Advisor
Robert Anthony Prosek, Faculty Reader - Keywords:
- specific language impairment
decay - Abstract:
- People with specific language impairment (SLI) experience poor sentence comprehension. It is unclear whether suboptimal maintenance of lexical information contributes to their comprehension problems. This study attempts to gauge the lexical decay rates of young adults with SLI, an understudied age group. Twenty-three young adults with SLI and twenty-three age-matched controls participated in an auditory word detection reaction time (RT) task wherein they heard a target word followed by 500 milliseconds of silence and a sentence containing the target word. We manipulated the time between the initial presentation of the target and the occurrence of the target in the sentence by either playing the sentence at a typical rate or slowing it down by fifty percent. We took the difference in RT between the slowed and typical rate conditions to indicate the degree of lexical decay that took place. To remove the possibility that group differences in RT were due to group differences in the ability to predict the occurrence of the target, we used reaction time on a measure of sentence processing efficiency as a covariate. In the sentence processing efficiency task, participants were presented with an image accompanied by an audio recorded sentence and were asked to press one of two buttons to indicate whether the event in the image matched the event in the sentence. The group with SLI showed a smaller difference in RT between the two conditions, suggesting that the young adults with SLI in our sample had a slower decay rate than their same-age peers.