Major Department

Speech Pathology and Audiology

College

College of Liberal Arts & Sciences

Degree

BA (Bachelor of Arts)

Session and Year of Graduation

Fall 2019

Honors Major Advisor

Yu-Hsiang Wu

Thesis Mentor

Dr. Bob McMurray

Abstract

Purpose: During speech perception, lexical candidates compete for word recognition. Incorrect candidates are briefly activated and then become suppressed. An aspect of word recognition is the ability to suppress these incorrect candidates especially in noisy environments. Previous work examining lexical inhibition and domain-general cognitive control found no correlation, suggesting cognitive control was not involved in spoken word recognition. Few studies have examined individual characteristics that impact a listener’s ability to process speech in noise. This study aims to understand the role cognitive control when speech is presented in noise.

Methods: We utilized the visual world paradigm (VWP) to measure lexical competition over the time course of word recognition. In the VWP, listeners heard words and clicked on the referent from a screen containing targets, cohorts, rhymes, and unrelated items, while eye-movements are monitored as a measure of lexical competition. Two classic cognitive controls tasks, the Flanker and Simon, were used to measure inhibition, a domain general cognitive mechanism. An experimental task, Temporal Flanker, was used because it simulates how speech unfolding over time.

Results: In the noise condition, listeners waited around 400 ms after the onset of the word to launch eye-movements. They showed slower and reduced activation of the target and increased competition. A significant interaction between Temporal Flanker score and timing of target fixations suggests that individuals who were better at the Temporal Flanker task were quicker to activate the target.

Discussion: The study showed a link between spoken word recognition and cognitive control. It has been well documented that the development of cognitive control is slow in childhood. This could have potential implications for children with Developmental Language Disorder or who use a cochlear implant. The development of cognitive control may be a potential avenue for intervention for language and hearing disorders.

Keywords

cognitive control, inhibition, speech perception

Total Pages

35

Copyright

Copyright © 2019 Sarah Plock

COinS
 

URL

https://ir.uiowa.edu/honors_theses/315