Poster D21, Wednesday, August 21, 2019, 5:15 – 7:00 pm, Restaurant Hall
No selective action verb impairment in Parkinson’s disease: evidence from Danish patients reading naturalistic texts
Andreas Højlund1, Marie Louise Holm Møller1,2, Sabine Grene Thomsen1,2, Karen Østergaard1,3, Mikkel Wallentin1,2;1Center of Functionally Integrative Neuroscience (CFIN), Aarhus University, 2Department of Linguistics, Cognitive Science and Semiotics, Aarhus University, 3Department of Neurology, Aarhus University Hospital
The present study investigates whether Parkinson’s disease (PD) patients are impaired in their processing of action-related verbs when reading naturalistic stories. Previous research suggests that PD patients exhibit difficulties in naming, producing, remembering and identifying action verbs. García et al. (2018) recently found that this specific deficit for PD patients seems to be present even when reading naturalistic stories (in Spanish) rather than isolated words or sentences. The present study is a replication of García et al.’s study (2018) with Danish-speaking PD patients and texts in Danish, while at the same time also an extension of the original study by including a crucial new contrast with both action and non-action verbs embedded in the same text. To this end, we constructed 2 x 2 naturalistic stories in Danish, with each pair of stories closely matched on several linguistic factors (e.g. word frequency and readability) similarly to García et al.’s stimuli. The first pair of texts, closely mirroring García et al.’s design, included one text with a high degree of action-content and one with a high degree of non-action content, while the second pair of texts integrated action and non-action content in both texts. With the extension of the second pair of texts, we sought to investigate whether the specific deficit for action content found in García et al.’s study could be due to a substantial build-up of action content over the course of one text compared to the other. 28 PD patients and 28 age- and gender-matched controls read the four stories and answered questions about situational (mainly time and place), action-related and non-action-related content. This allowed us to investigate the hypothesis that PD patients would perform worse on action content than on situational and non-action content compared to controls. Results showed no significant differences in performance between PD patients and controls. In fact, for several contrasts, equivalence tests showed no practical difference between the two groups’ performances. However, we did see a significant main effect of verb type as both groups generally performed worse on non-action-related questions compared to action-related and situational questions, suggesting that non-action content may be generally harder to remember (also when embedded in naturalistic stories). Our finding that Danish-speaking PD patients do not seem to be specifically impaired in their action language processing underlines the importance of testing such claims in cross-linguistic and cross-cultural designs. Further research is needed to properly delineate whether typological differences between Spanish and Danish may affect PD patients’ language processing differently or whether the originally reported effects are not replicable. In broader terms, research within the field of action language processing in PD patients is still in its early stages and it is thus still unclear whether action verb impairment is a sui generis deficit in PD.
Themes: Disorders: Acquired, Meaning: Lexical Semantics
Method: Behavioral