The production of contrastive stress in people with Parkinson's disease
Abstract
Purpose: The purpose of this study was twofold: To determine what acoustic cues people with Parkinson's disease (PD) used to mark contrastive stress and to determine how those cues differed from healthy controls. Methods: Twenty six participants were studied, 13 with a diagnosis of Parkinson's Disease and 13 age and sex-matched controls. Participants read a sentence on a computer monitor and were asked to produce it once neutrally, then contrastively in response to examiners' questions. Acoustic cues (frequency, duration, and intensity) were measured to determine how the participants produced contrastive stress, and perceived stress ratings of each utterance were also collected from ten untrained listeners. Results: Both groups were found to use similar patterns of vowel durations, frequency, and intensity across sentence positions and word stress patterns. However, raters judged people with PD as significantly more likely than controls to place stress on the wrong word/not stress any words in a given utterance. Conclusion: Contrary to previous literature, these data suugest that individuals with PD can produce changes in frequency, duration, and intensity in a contrastive stress context. However, similar to previous findings, individuals with PD were perceived as less effective at marking contrastive stress. Future research should examine what acoustic cues contribute to the perceptual differences between individuals with PD and control participants.
Degree
M.S.
Advisors
Huber, Purdue University.
Subject Area
Speech therapy
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