Executive functions & story retelling in aphasia (Dutta et al., 2024)

Purpose: Although individuals with aphasia commonly exhibit challenges in executive functioning (EF) and spoken discourse, there is limited research exploring connections between these abilities within this specific population. Therefore, this study investigated the relationship between verbal and nonverbal EF and narrative productions in aphasia using a multilevel linguistic approach.

Method: Participants included 22 persons with aphasia (PWA) and 24 age- and education-matched, neurologically healthy controls (NHC). All participants completed assessments for EF and a story retelling task. Narrative samples were analyzed for microlinguistic (productivity, lexical and syntactic features, semantic content, word and sentence errors) and macrolinguistic (coherence, informational content, organization, and language use) characteristics. Correlational analyses were employed to explore the relationships among narrative variables. EF factors, extracted from principal component analysis, were used as predictive variables in hierarchical stepwise regression analyses to evaluate their role in predicting narrative performances of PWA and NHC.

Results: Relative to NHC, PWA exhibited impaired narrative performance affecting both microlinguistic and macrolinguistic levels. Breakdowns at the structural level (i.e., reduced productivity, syntax, lexical retrieval, and diversity) correlated with impaired story completeness, organization, and connectedness; this relationship was more prominent for PWA. Three EF factors representing (1) verbal EF, (2) verbal and nonverbal fluency, and (3) nonverbal EF were extracted. Factors 1 and 2 largely predicted narrative performance, whereas Factor 3 (i.e., nonverbal EF) contributed prominently to predicting macrolinguistic discourse performance in both groups although accounting for less variance in the data. Overall, lower EF scores, particularly verbal EF variables, predicted poor narrative performance in both groups.

Conclusions: Our results indicate that both linguistic and extralinguistic cognitive abilities play a role in story retelling performances among PWA. Notably, both verbal and nonverbal EF skills were found to be correlated with narrative abilities. However, the extent of their contributions varied depending on the discourse levels assessed. These findings provide a significant contribution to our understanding of the cognitive factors associated with breakdowns in discourse among PWA and highlight the importance of comprehensive assessment of EF and discourse within this population.