The role of prosody in the foreign accent syndrome: A single-subject study

Abstract

Foreign accent syndrome (FAS) is an unusual motor speech disorder involving a perceived foreign accent resulting from brain damage. An important question concerning FAS is the role of prosodic deficits, including the extent to which difficulties in stress assignment may contribute to segmental errors. In this study, acoustic analyses were performed on the speech of a 46-year-old female patient who presented with a pseudo-accent described as Swedish. Stop consonant VOT, consonant burst spectra and duration, and vowel formant frequencies and trajectories were analyzed, along with prosodic cues for lexical stress assignment and sentence-level intonation. Results indicated that the patients vowels were centralized and realized with reduced dynamic specifications. There was a strong tendency to realize the English alveolar flap as a full stop, and to produce flaps that had greater-than-normal closure durations. Lexical stress assignment was frequently inaccurate and highly variable, with similar problems noted for non-speech stimuli. Overall, the data suggest that stress assignment deficits were the basis for most of her segmental difficulties. The findings support the view that local prosodic deficits play a critical role in FAS.