Prosodic changes in aphasic speech: timing

Abstract

Controversy remains about the impairment of prosody in aphasia, particularly with regard to speech timing. This paper addresses this topic through an analysis of timing in four sets of a common morphological paradigm. The paradigm consisted of a basic form (stem) and two longer derived forms (e.g. zip, zipper, zippering). Normally, vowel durations are shorter in longer derived forms (e.g. zippering) than in the stem (e.g. zip), due to a process called ‘initial shortening’. Twelve patients with aphasia (four each Broca, Wernicke, and Anomic), and 11 age-matched healthy adults were assessed. Structural (CT) and functional brain imaging (PET) were available for all patients. While all groups showed initial shortening between the stem and the derived forms, the patients with Broca's aphasia presented an inverse pattern between the two derived forms (longer initial vowel in ‘zippering’ than ‘zipper’), and the patients with Wernicke's aphasia produced significantly longer vowel durations overall than the healthy participants. The results are related to radiological information regarding the location of structural and functional brain damage and relative preservation and loss of prosodic features in cerebral damage.

Keywords:

• acoustic analysis
• aphasia
• prosody
• timing

Acknowledgements

This research was supported in part by the Intramural Research Program of the NIH, National Institute on Aging. We appreciate the assistance of Andrew Lanto and John J. Sidtis in statistical consulting. We also thank two anonymous reviewers for their comments and Wayne Hanson for his support on this project.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Notes

1. Age for one healthy adult was not available.