Between-Session Intraindividual Variability in Phonological, Lexical, and Semantic Processing in Post-Stroke Aphasia: a Pilot Study

EasyChair Preprint 6526

Abstract

Neurolinguistics and cognitive neuropsychology have a long-standing tradition to focus on mean-level performance measures such as accuracy and mean reaction times (RTs). However, recent studies suggest that intraindividual variability (IIV) – within-person variations in performance over time – can further complement our understanding of the pattern of behavior. Despite the common clinical observation that people with aphasia often produce marked variations in their day-to-day performance on a variety of tasks, to the best of our knowledge, no study has systematically investigated IIV in language (i.e., phonological, lexical, and semantic processing) and the relationship between IIV in language processing and performance on standard measures of language in post-stroke aphasia. In this study, 13 people with stroke-aphasia (PWA) were assessed on four consecutive days using the same set of six auditory experiments on each day. The experiments tested phonological, lexical, and semantic processing with and without WM demand (PHON, PHON-WM, LEX, LEX-WM, SEM, SEM-WM, respectively). In addition, the Western Aphasia Battery (WAB) and the Comprehensive Aphasia Test-Hungarian (CAT-H) were administered to assess aphasia severity and language profile. To examine IIV across days, we calculated two coefficients of variation (COV) for each task – one for accuracy (ACC-COV) and one for RTs (RT-COV). ACC-COV in PHON showed a significant negative correlation with the CAT-H and a marginally significant correlation with the WAB AQ. ACC-COV in SEM showed a significant negative correlation with both tests. RT-COV in PHON and LEX showed non-significant positive correlations with the CAT-H and the WAB. These results indicate that (1) PWA show IIV in language processing across days, (2) greater IIV in accuracy may be associated with more severe aphasia in post-stroke aphasia, and (3) IIV in accuracy and RTs may be driven by different underlying mechanisms.

Keyphrases: RT variability, between-session variability, consistency, intraindividual variability, language, post-stroke aphasia

@booklet{EasyChair:6526,
  author    = {Lilla Zakariás and Ágnes Lukács},
  title     = {Between-Session Intraindividual Variability in Phonological, Lexical, and Semantic Processing in Post-Stroke Aphasia: a Pilot Study},
  howpublished = {EasyChair Preprint 6526},
  year      = {EasyChair, 2021}}