The current study focused on the semantic dimension of verbs by categorizing verbs based on the semantic weight (heavy vs. light) from a verb fluency task. The purpose of the study is to investigate whether normal elderly adults demonstrated any differentially greater difficulties depending on the verb types compared to the young group.  

A total of 115 Korean-speaking individuals (55 young, 60 elderly) participated in this study. Participants were asked to produce as many verbs as possible within 60 seconds. The performance was analyzed according to semantic weight of verb (heavy vs. light), the number of clusters, mean cluster size and the number of switching. Scores of digit span task were administered as working memory measures. 

Elderly adults demonstrated differentially greater difficulties in generating heavy than light verbs compared to the younger group. Also, elderly adults presented smaller mean cluster size in the heavy than light verb and fewer switching than younger adults. Considering that heavy verbs carry more semantically complex features than light verbs, it is likely that more semantic units need to be activated to retrieve the verbs with heavy semantic weight. Education was the significant predictor that was included into all dependent measures across the board for the heavy verbs. Education is one of the critical factors that are associated with cognitive reserve (Stern, 2006), suggesting that individuals with greater cognitive research are less vulnerable to cognitive decline. The current results indicate that the abilities to retrieve semantically heavy verbs are more vulnerable to aging and education may account for their decreased abilities as a cognitive reserve. Semantic-based analyses can provide additional qualitative analyses of the verbal fluency task to detect the aging effects and their related demographic factors.