Disambiguating Semantic Processing and Executive Function in Post-Stroke Aphasia

Poster Session E - Monday, March 31, 2025, 2:30 – 4:30 pm EDT, Back Bay Ballroom/Republic Ballroom

Ryan Dixon¹ (rldixon@email.sc.edu), Dirk Den Ouden¹, Julius Fridriksson¹, Rutvik Desai², William Matchin¹; ¹Department of Communication Sciences and Disorders, University of South Carolina, ²Department of Psychology, University of South Carolina

Semantic processing, the ability to access or apply conceptual knowledge, can be impaired in neuropsychological populations and is commonly assessed with standard non-linguistic picture verification measures such as the Pyramids and Palm Trees Test (PPT) and Kissing and Dancing Test (KDT). However, prior research suggests these measures have substantial executive function demands. We aimed to assess this claim in 79 post-stroke aphasia patients. First, we assessed whether the PPT and KDT have significant convergent validity with semantic processing as assessed through the Western Aphasia Battery (WAB) comprehension subscore and the Northwestern Assessment of Verbs and Sentences (NAVS) verb and sentence comprehension tests, including the Wechsler Adult Intelligence Scale (WAIS) matrices test as a control for executive function demands. Second, we assessed whether these measures predict damage to areas widely implicated in conceptual-semantic processing. The results revealed that the PPT and KDT significantly correlated with performance on the WAB-R and NAVS comprehension measures, but this relationship disappeared when WAIS matrices was included as a covariate, suggesting the convergent validity of the PPT and KDT may be driven by a shared executive function component. After controlling for multiple comparisons, the PPT only significantly related to damage to the posterior cingulate gyrus and the KDT did not significantly relate to damage to any semantics-related brain regions, unlike the linguistic comprehension measures which significantly related to several of these regions. These results indicate that the PPT and KDT may have limited utility in assessing conceptual-semantic deficits in left-hemisphere chronic stroke survivors.

Topic Area: LANGUAGE: Semantic