Atypical neural functions underlying phonological processing and silent rehearsal in children who stutter

Abstract

Phonological processing was examined in school-age children who stutter (CWS) by assessing their performance and recording event-related brain potentials (ERPs) in a visual rhyming task. CWS had lower accuracy on rhyming judgments, but the cognitive processes that mediate the comparisons of the phonological representations of words, as indexed by the rhyming effect (RE) ERP, were similar for the stuttering and normally fluent groups. Thus the lower behavioral accuracy of rhyming judgments by the CWS could not be attributed to that particular stage of processing. Instead, the neural functions for processes preceding the RE, indexed by the N400 and CNV elicited by the primes and the N400 elicited by the targets, suggest atypical processing that may have resulted in less efficient, less accurate rhyming judgment for the CWS. Based on the present results, it seems likely that the neural processes related to phonological rehearsal and target word anticipation, as indexed by the CNV, are distinctive for CWS at this age. Further, it is likely that the relative contributions of the left and right hemispheres differ in CWS in the stage of processing when linguistic integration occurs, as indexed by the N400. Taken together, these results suggest that CWS may be less able to form and retain a stable neural representation of the prime onset and rime as they anticipate the target presentation, which may lead to lower rhyming judgment accuracy.

Effects of word frequency and phonological neighborhood characteristics on confrontation naming in children who stutter and normally fluent peers

“…For example, AWS have also shown slower RTs on tasks requiring monitoring of phonological structure (such as judging whether stimuli rhyme) and lexical analysis (making semantic category judgments; Bosshardt, 1993Bosshardt, , 1994Weber-Fox, Spruill, Spencer, & Smith, 2008), as well as while monitoring for particular phonemes (Sasisekaran, De Nil, Smyth, & Johnson, 2006). Some of these effects are exacerbated under conditions of increased cognitive load (Weber-Fox et al, 2004) Weber-Fox and colleagues noted that the data to date are "consistent with the hypothesis that underlying neural processes mediating lexical access may operate atypically in adults who stutter in the absence of overt speech" (Weber-Fox et al, 2004, p. 1246.…”

How Stuttering Develops: The Multifactorial Dynamic Pathways Theory

“…ERPs are sensitive indicators of language proficiency in children and adults even when the range of participants' proficiencies is within normal limits Pakulak & Neville, 2010). In a series of studies from our laboratory, we have used paradigms that elicit well-known languagerelated ERP components (e.g., N400, P600) to determine if and how neural activity patterns mediating semantic, syntactic, and phonological processing differ for AWS and CWS compared with their fluent peers (e.g., Cuadrado & WeberFox, 2003;Mohan & Weber, 2015;Usler & Weber-Fox, 2015;Weber-Fox, 2001;Weber-Fox & Hampton, 2008;Weber-Fox, Hampton Wray, & Arnold, 2013;Weber-Fox, Spencer, Spruill, & Smith, 2004;Weber-Fox, Spruill, Spencer, & Smith, 2008). The N400 component reflects the identification, retrieval, and integration of semantic meaning (Kutas & Federmeier, 2011), and the P600 is thought to index reanalysis and repair processes, often for violations of syntax or grammar or garden path sentences (Gouvea et al, 2010).…”

Atypical central auditory speech-sound discrimination in children who stutter as indexed by the mismatch negativity

“…To the best of our knowledge, only a few studies have examined the neural correlates of stuttering in children (Beal et al, 2011;Beal, 2010;Chang et al, 2008;Kaganovich et al, 2010;Sato et al, 2011;Weber-Fox, Spruill, Spencer, & Smith, 2008;Weber-Fox, Hampton Wray, & Arnold, 2013). Neuroanatomical studies conducted by Chang et al (2008) and Beal (2010) showed reduced gray matter volume in children who stutter (CWS) in the left inferior frontal gyrus, and in temporal regions, compared to typically developing children with fluent speech.…”