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Global coherence and cognition in PD (Rogalski et al., 2022)

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posted on 2022-08-05, 18:24 authored by Yvonne Rogalski, Sarah E. Key-DeLyria, Audrey Hazamy, Lori J. P. Altmann

Purpose: This study compared global coherence (GC) in individuals with Parkinson’s disease (PD) to a healthy older adult (HOA) group during single (sitting) and dual (stationary cycling) tasks. Additionally, it explored the relationship between GC and cognition in PD.

Method: Thirty-seven individuals with PD and 19 HOAs participated in the prospective, cross-sectional study. Participants completed discourse monologues elicited using published prompts while seated and while pedaling a stationary bicycle. Four rating levels of GC were analyzed (GC1 = no relationship to the topic, GC2 = remote relationship, GC3 = conditional relationship, and GC4 = complete relationship) using a published protocol with good interrater reliability and test–retest stability. Participants completed a battery of cognitive tasks, from which four latent factors were extracted: processing speed, working memory, inhibition, and updating.

Results: Linear mixed modeling identified significant effects of GC level and GC level interactions with group, processing speed, and inhibition. The Group × GC Level interaction reflected that the PD group had a higher proportion of GC2 and GC1 utterances and fewer GC4 utterances than the HOA group. No differences between single and dual task conditions were found. Faster speed of processing predicted more GC4 utterances, whereas slower speed of processing predicted more G1 utterances. Better inhibition predicted fewer GC2 utterances. Group also predicted GC4 and GC2 proportions.

Conclusions: Individuals with PD experienced greater difficulties with GC than HOAs. Processing speed and inhibition contributed significantly to GC across groups. Analysis of GC should be considered an informative addition to assessment of communicative effectiveness in PD.

Supplemental Material S1. Scored discourse sample from a participant with PD.

Supplemental Material S2. Factor loadings from the principal components analysis of cognitive test scores.

Supplemental Material S3. Results of the best model from the linear mixed model analysis.

Rogalski, Y., Key-DeLyria, S. E., Hazamy, A., & Altmann, L. J. P. (2022). Global coherence and cognition in Parkinson's disease. Journal of Speech, Language, and Hearing Research. Advance online publication.


Research reported in this publication was partially supported by the National Institute of Aging of the National Institutes of Health under award number R21AG033284. Participant recruitment, data collection, and initial transcriptions were funded by the National Institutes of Health (NIH), approximately 60% of the project, while the remainder of the project was funded by the National Parkinson Foundation Center of Excellence, the Inform Research Database at the University of Florida, and the home institutions of the authors, which funded the authors’ time.