Core-Lexicon and Main-Concept Production During Picture-Sequence Description in Adults Without Brain Damage and Adults With Aphasia

Abstract

Purpose We sought to identify the core lexicon of a picture-description task using transcripts from the AphasiaBank database and to determine differences in core-lexicon usage between control speakers and persons with aphasia (PWAs). We also investigated the relationship between core lexicon and an established discourse measure, main-concept analysis. Method A core lexicon was developed by identifying lemmas produced by 92 control speakers. Transcripts were scored—165 control transcripts and 238 PWA transcripts—using the core lexicon and a recently developed main-concept list. Median tests examined differences between controls, PWAs, and aphasia subtypes. Spearman's correlations assessed the relationship between core-lexicon and main-concept performance. Results A 24-item core lexicon was identified. Significant differences were found between control speakers and PWAs, and between aphasia subtypes, for core-lexicon and main-concept scores. Core-lexicon and main-concept performance was significantly and positively correlated for all groups. Conclusions We report the development of a core lexicon, differences in core-lexicon usage between speakers, and the relationship between core-lexicon and main-concept scores. Research is needed to determine the clinical utility and psychometric properties of these discourse measures and their potential contribution to multilevel discourse analysis of functional communication.