Verb Production in Aphasia: Testing the Division of Labor between Syntax and Semantics.

Some individuals with aphasia preferably use semantically general light verbs, whereas others prefer semantically specific heavy verbs. This study aimed to test Gordon and Dell's "division of labor" hypothesis that light versus heavy verb usage depends on syntactic and semantic processes, respectively. In a retrospective analysis of data from the AphasiaBank corpus, narrative language of neurologically healthy individuals and individuals with aphasia was analyzed for the proportion of light verbs used, and its relationship with narrative measures of syntactic and semantic sophistication and verb naming scores was examined. In individuals with aphasia, light verb usage was positively correlated with a syntactic measure (developmental sentence score) and negatively associated with two semantic measures (idea density and verb naming). For healthy individuals, the number of verbs per utterance, which is a measure of syntactic complexity, predicted light verb use. These findings suggest that light verb usage in aphasia observes an inverse relationship with syntactic and semantic abilities, supporting the division of labor hypothesis.