Orofacial Movements Associated With Fluent Speech in Persons Who Stutter

Abstract

This study was intended to replicate and extend previous findings that (a) during fluent speech persons who stutter (PS) and those who do not (NS) differ in their vocal tract closing movements (L. Max, A. J. Caruso, and V. L. Gracco, 2003) and (b) ratios relating lip and tongue speed to jaw speed increase with stuttering severity (M. D. McClean and C. R. Runyan, 2000). An electromagnetic system was used to record movements of the upper lip, lower lip, tongue, and jaw of 43 NS and 37 PS during productions of a nonsense phrase and a sentence. Measurement and analysis of movement speeds, durations, and ratios of lip and tongue speed to jaw speed were performed on fluent productions of a nonsense phrase and sentence. Statistical comparisons were made between PS with low and high stuttering severity levels (LPS and HPS) and NS. Significant variations across groups in movement speed and duration were observed, but the pattern of these effects was complex and did not replicate the results of the two earlier studies. In the nonsense phrase, significant reductions in lower lip closing duration, jaw closing duration, and jaw closing speed were seen in PS. In the sentence task, HPS showed elevated tongue opening and closing durations. For tongue opening in the sentence, LPS showed elevated speeds and HPS showed reduced speeds. The elevated speeds for LPS are interpreted as a contributing factor to speech disfluency, whereas the reduced speeds and increased durations in HPS are attributed to adaptive behavior intended to facilitate fluent speech. Significant group effects were not seen for the speed ratio measures. Results are discussed in relation to multivariate analyses intended to identify subgroups of PS.

Speech motor control in fluent and dysfluent speech production of an individual with apraxia of speech and Broca's aphasia

“…If AOS represents a basic neurological dysfunction in speech motor control, it seems logical to assume that its influence should always be present, even during the production of perceptually fluent speech (see McClean, Tasko, & Runyan, 2004, for a similar argument with respect to stuttering). If so, it seems also reasonable to suggest that individuals with AOS when they speak fluent must apply compensatory motor control strategies to overcome this problem (e.g.…”

A Lag in Speech Motor Coordination During Sentence Production Is Associated With Stuttering Persistence in Young Children

“…Stuttering has long been described as a disorder of speech motor discoordination and instability, with intervals of fluency and disfluency not observed as dichotomous phenomena, but instead as events along a continuum of speech motor coordination (Adams & Runyan, 1981;Van Riper, 1982;Zimmermann, Smith, & Hanley, 1981). Even when perceptually fluent, the speech of individuals who stutter has been associated with atypical speech motor coordination (Caruso, Abbs, & Gracco, 1988;McClean, 2004;McClean, Kroll, & Loftus, 1990;Zimmermann, 1980) and increased articulatory variability (Kleinow & Smith, 2000;MacPherson & Smith, 2013;Smith, Goffman, Sasisekaran, & Weber-Fox, 2012) compared to typically fluent controls. Adults who stutter (AWS) have exhibited atypical speech and nonspeech motor performance compared to their typical peers, specifically in coordination tasks between different motor components or effector systems (Forster & Webster, 2001;Zelaznik, Smith, Franz, & Ho, 1997).…”

Articulatory Variability in Cluttering

“…The exclusion criteria in this study differ from comparable studies on stuttering [7,[32][33][34] in that they usually only analysed fluent utterances as judged by speech and language pathologists. We only excluded data when analysis showed incomplete articulatory movements (see below).…”