Rhyming abilities in young children who stutter: Behavioral and electrophysiological evidence

Christine B Rothermel, Purdue University

Abstract

Empirical evidence suggests that phonological processing disorders and stuttering may have a high rate of co-occurrence in children, leading to the hypothesis that the two interact in some way. While the results of some studies provide evidence that supports this idea, findings from other studies refute this hypothesis (Nippold, 2002). Nippold, based on a meta-analysis of the extant data, concluded that previous studies linking phonological processing to stuttering failed to exclude children with phonological language impairments, creating a false association (Nippold, 2001). Using event-related brain potentials (ERPs), the current study aims to further investigate the relationship between stuttering and neural mechanisms for phonological processing in young children who stutter (CWS). Importantly, this study employed strict inclusion criteria for behavioral performance measures for both CWS and children with normal fluency (CWNF), ensuring that all children had overall language, phonological, and working memory abilities within normal limits. Thirty-two children, ages 5;11 to 6;11, participated in this study. Sixteen participants (13 males, 12 right-handed) were CWS and 16 children (11 males, 11 right-handed) were CWNF. Each child completed the following experimental behavioral assessments: the Dollaghan Nonword Repetition Task (Dollaghan & Campbell, 1998), the rhyming portion of The Phonological Awareness Test (PAT; Robertson & Salter, 1997), and a nonword rhyming task created such that the difficulty and length of nonwords matched that of the PAT. ERPs were elicited by nonword pairs in an auditory rhyme judgment paradigm (stimuli from Coch, Grossi, Skendzel & Neville, 2005). Although the groups performed with similar accuracy in making rhyme judgments, neural indices of phonological processing (CNV and N400) were subtly different in CWS. Reduced amplitude in the early CNV interval and less reliable facilitation of the onset of the N400 for rhyming targets in CWS suggested that the stages of phonological processing, working memory updates, and rime comparison processes for making the rhyme judgments functioned less efficiently. These results suggest that neural processes mediating the rhyme judgment may operate atypically in CWS, even when phonological and auditory working memory abilities are age appropriate and matched between the two groups. Therefore, the results of this study provide support that the development of stuttering affects widespread processes in the brain related to many aspects of language processing.

Degree

M.S.

Advisors

Weber-Fox, Purdue University.

Subject Area

Speech therapy|Cognitive psychology

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