Working memory and speech in Parkinson’s disease (Dragicevic et al., 2024)
Purpose: The purpose of this study was to determine the effect of a concurrent working memory task on acoustic measures of speech in individuals with Parkinson’s disease (PD).
Method: Individuals with PD and age- and sex-matched controls performed a speaking task with and without a Stroop-like concurrent working memory task. Cepstral peak prominence, low-to-high spectral energy ratio, fundamental frequency (fo) standard deviation, articulation rate, pause duration, articulatory–acoustic vowel space, relative fo, mean voice onset time (VOT), and VOT variability were calculated for each condition. Mixed-model analyses of variance were performed to determine the effects of group, condition (presence of the concurrent working memory task), and their interaction on the acoustic measures.
Results: All measures except for VOT variability, mean pause duration, and relative fo offset differed between people with and without PD. Cepstral peak prominence, articulation rate, and relative fo offset differed as a function of condition. However, no measures indicated disparate effects of condition as a function of group.
Conclusion: Although differentially impactful on limb motor function in PD, here a concurrent working memory task was not found to be differentially disruptive to speech acoustics in PD.
Supplemental Material S1. ANOVA results.
Figure S1-1. Mean and 95% confidence interval for cepstral peak prominence (CPP) for people with Parkinson’s disease (PD) and controls (CT) under both the congruent (C) and incongruent (I) task conditions.
Figure S1-2. Mean and 95% confidence interval for low-to-high spectral energy ratio (L/H Ratio) for people with Parkinson’s disease (PD) and controls (CT) under both the congruent (C) and incongruent (I) task conditions.
Figure S1-3. Mean and 95% confidence interval for relative fundamental frequency (RFF) in semitones (ST) for people with Parkinson’s disease (PD) and controls (CT) under both the congruent (C) and incongruent (I) task conditions.
Figure S1-4. Mean and 95% confidence interval for fundamental frequency standard deviation (fo SD) for people with Parkinson’s disease (PD) and controls (CT) under both the congruent (C) and incongruent (I) task conditions.
Figure S1-5. Mean and 95% confidence interval for articulation rate for people with Parkinson’s disease (PD) and controls (CT) under both the congruent (C) and incongruent (I) task conditions.
Figure S1-6. Mean and 95% confidence interval for pause duration for people with Parkinson’s disease (PD) and controls (CT) under both the congruent (C) and incongruent (I) task conditions.
Figure S1-7. Mean and 95% confidence interval for Articulatory Acoustic Vowel Space (AAVS) for people with Parkinson’s disease (PD) and controls (CT) under both the congruent (C) and incongruent (I) task conditions.
Figure S1-8. Mean and 95% confidence interval for mean voice onset time (Mean VOT) for people with Parkinson’s disease (PD) and controls (CT) under both the congruent (C) and incongruent (I) task conditions.
Figure S1-9. Mean and 95% confidence interval for voice onset time (VOT) variability (standard deviation) for people with Parkinson’s disease (PD) and controls (CT) under both the congruent (C) and incongruent (I) task conditions.
Dragicevic, D. A., Dahl, K. L., Perkins, Z., Abur, D., & Stepp, C. E. (2024). Effects of a concurrent working memory task on speech acoustics in Parkinson’s disease. American Journal of Speech-Language Pathology, 33(1), 418–434. https://doi.org/10.1044/2023_AJSLP-23-00214