Alignment following left and right hemisphere damage

Abstract

Background: Patients with fluent aphasia have been reported to exhibit abnormal timing of some linguistic units, but the basis of this deficit is unclear. It has been hypothesised that these patients have impaired ability to control temporal information stored in lexical items, but timing at the level of intonation phrase (IP) is intact for them. One aspect of temporal control at the level of IP is alignment, the relative timing of events in fundamental frequency (F0) contours associated with intonation and events in the segmental string. I am grateful to Hugh Buckingham and an anonymous reviewer for their comments and suggestions on a draft of this paper. This research was supported by NIH (NIDCD) grant 5R03DC004955‐03. Aim: The present study sought to determine whether patients with fluent aphasia have intact ability for alignment. Methods & Procedures: Absolute and relative measures of intervals between F0 peaks and valleys, as well as syllable duration were evaluated in sentences produced by patients with fluent aphasia, nonfluent aphasia, right hemisphere damage (RHD), and a group of neurologically normal individuals. The productions were evaluated perceptually by five neurologically normal native speakers. Outcomes & Results: The patients with fluent aphasia performed poorly on absolute and relative measures of alignment. Their nonfluent counterparts exhibited abnormally long absolute durations on all measures including final syllable length, and the RHD performed comparably with the control participants on both absolute and relative measures of alignment and syllable duration. All groups were perceptually indistinguishable. Conclusion: The data for all three groups of patients are consistent with previous reports on speech timing following brain damage. The performance of the patients with fluent aphasia on alignment does not support the view that these patients have intact ability for speech timing at the level of IP.