Name: Rob Ashwill

Master’s Thesis Defense Meeting

Date: Friday, February 14, 2020

Time: 3-5 PM
Location: J.S. Coon Building, Room 150
 
Advisor:
Daniel Spieler, Ph.D. (Georgia Tech)
 
Thesis Committee Members:
Daniel Spieler, Ph.D. (Georgia Tech)
Chris Hertzog, Ph.D. (Georgia Tech)
Thackery Brown, Ph.D. (Georgia Tech)
 
Title: FEATURAL DENSITY IN PICTURE NAMING AMONG COLLEGE AGE AND OLDER ADULTS

Abstract: 

When naming pictures, speakers are slower to name pictures with multiple appropriate labels (e.g., couch/sofa) compared to pictures consistently given a single label. This increased naming time is generally seen as a reflection of the time needed to resolve competition between the competing labels. Older speakers show a greater influence of name agreement that could reflect a specific age-related increase in sensitivity to lexical competition when speaking. The present study examines speakers’ sensitivity to a more pervasive form of lexical competition.

Using normative data in which individuals report features associated with object concepts, it is possible to measure the extent to which concepts share features with other concepts. Pictures matched with concepts with high featural overlap with other concepts should show greater competition during naming than those matched to concepts with lower levels of featural overlap. Initial evidence in younger speakers is consistent with this prediction. Here, we conducted a set of experiments to replicate this result in younger speakers and test the prediction that older speakers will be more sensitive to variations in featural overlap than younger speakers. We observed a marginal negative relationship between featural overlap and response times if participants were not pre-exposed to stimuli. With pre-exposure we saw a significant negative effect of feature overlap and response times in both young and older adults. There was no clear differential effect of featural overlap on semantic competition for young and older adults.