title: Core-Lexicon and Main-Concept Production During Picture-Sequence Description in Adults Without Brain Damage and Adults With Aphasia.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
authors.forename: Sarah Grace
authors.initials: SG
authors.lastname: Dalton
authors.forename: Jessica D
authors.initials: JD
authors.lastname: Richardson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001037:Aphasia / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual; D011594:Psychometrics; D012016:Reference Values; D012660:Semantics; D014705:Verbal Behavior; D014825:Vocabulary