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Neurodevelopment for syntactic processing distinguishes childhood stuttering recovery versus persistence.

Usler E, Weber-Fox C - J Neurodev Disord (2015)

Bottom Line: During the comprehension of English sentences, ERP activity mediating semantic and syntactic (phrase structure) processing did not distinguish CWS-Per, CWS-Rec, and CWNS.However, identical phrase structure violations within Jabberwocky sentences elicited a P600 in CWNS and CWS-Rec, but an N400-like effect in CWS-Per.Unlike CWS-Rec and CWNS, the lack of semantic context in Jabberwocky sentences seemed to affect the syntactic processing strategies of CWS-Per, resulting in the elicitation of semantically based N400-like activity during syntactic (phrase structure) violations.

View Article: PubMed Central - PubMed

Affiliation: Department of Speech, Language, and Hearing Sciences, Purdue University, Lyles-Porter Hall, 715 Clinic Drive, West Lafayette, IN 47907 USA.

ABSTRACT

Background: Characterized by the presence of involuntary speech disfluencies, developmental stuttering is a neurodevelopmental disorder of atypical speech-motor coordination. Although the etiology of stuttering is multifactorial, language development during early childhood may influence both the onset of the disorder and the likelihood of recovery. The purpose of this study was to determine whether differences in neural indices mediating language processing are associated with persistence or recovery in school-age children who stutter.

Methods: Event-related brain potentials (ERPs) were obtained from 31 6-7-year-olds, including nine children who do not stutter (CWNS), 11 children who had recovered from stuttering (CWS-Rec), and 11 children who persisted in stuttering (CWS-Per), matched for age, and all with similar socioeconomic status, nonverbal intelligence, and language ability. We examined ERPs elicited by semantic and syntactic (phrase structure) violations within an auditory narrative consisting of English and Jabberwocky sentences. In Jabberwocky sentences, content words were replaced with pseudowords to limit semantic context. A mixed effects repeated measures analysis of variance (ANOVA) was computed for ERP components with four within-subject factors, including condition, hemisphere, anterior/posterior distribution, and laterality.

Results: During the comprehension of English sentences, ERP activity mediating semantic and syntactic (phrase structure) processing did not distinguish CWS-Per, CWS-Rec, and CWNS. Semantic violations elicited a qualitatively similar N400 component across groups. Phrase structure violations within English sentences also elicited a similar P600 component in all groups. However, identical phrase structure violations within Jabberwocky sentences elicited a P600 in CWNS and CWS-Rec, but an N400-like effect in CWS-Per.

Conclusions: The distinguishing neural patterns mediating syntactic, but not semantic, processing provide evidence that specific brain functions for some aspects of language processing may be associated with stuttering persistence. Unlike CWS-Rec and CWNS, the lack of semantic context in Jabberwocky sentences seemed to affect the syntactic processing strategies of CWS-Per, resulting in the elicitation of semantically based N400-like activity during syntactic (phrase structure) violations. This vulnerability suggests neural mechanisms associated with the processing of syntactic structure may be less mature in 6-7-year-old children whose stuttering persisted compared to their fluent or recovered peers.

No MeSH data available.


Related in: MedlinePlus

N400-like mean amplitude for the Jabberwocky syntactic condition. Group mean amplitude (μV) (600–900 ms) elicited by syntactic (phrase structure) violations within Jabberwocky sentences. Averaged across central-parietal electrodes (C3, CP3, P3, CZ, CPZ, PZ, C4, CP4, and P4), only CWS-Per show a larger negativity (N400-like effect) elicited by phrase structure violations relative to the canonical (negative plotted up).
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Fig5: N400-like mean amplitude for the Jabberwocky syntactic condition. Group mean amplitude (μV) (600–900 ms) elicited by syntactic (phrase structure) violations within Jabberwocky sentences. Averaged across central-parietal electrodes (C3, CP3, P3, CZ, CPZ, PZ, C4, CP4, and P4), only CWS-Per show a larger negativity (N400-like effect) elicited by phrase structure violations relative to the canonical (negative plotted up).

Mentions: There was no condition effect for the later (600–900 ms) negativity at medial/lateral electrodes [F(1,28) = .93, p = .34] nor at midline electrodes [F(1,28) = .00, p = .99]. However, a group × condition effect, as graphed in Figure 3, revealed differences between groups in the elicitation of a later negativity (600–900 ms) at lateral/medial electrodes [F(2,28) = 6.45, p = .01], but not midline electrodes [F(2,28) = 1.88, p = .17]. Step-down ANOVAs revealed differences between CWNS and CWS-Per [F(1,18) = 11.16, p = .004] and between CWS-Rec and CWS-Per [F(1,20) = 9.19, p = .01], but not between CWNS and CWS-Rec [F(1,18) = .01, p = .94]. Figure 5 displays a group N400-like mean amplitude averaged across central-parietal electrodes. Relative to the canonical condition, phrase structure violations elicited a negativity only for CWS-Per. However, as graphed on Figure 6, significant overlap exists in ERP elicitation across participants. This reveals considerable individual differences in neural patterns, including N400-like activity, elicited over central-parietal sites. Still, no positive activity over 5 microvolts (μV) was elicited by phrase structure violations for any of the CWS-Per participants, unlike numerous CWNS and CWS-Rec participants.Figure 5


Neurodevelopment for syntactic processing distinguishes childhood stuttering recovery versus persistence.

Usler E, Weber-Fox C - J Neurodev Disord (2015)

N400-like mean amplitude for the Jabberwocky syntactic condition. Group mean amplitude (μV) (600–900 ms) elicited by syntactic (phrase structure) violations within Jabberwocky sentences. Averaged across central-parietal electrodes (C3, CP3, P3, CZ, CPZ, PZ, C4, CP4, and P4), only CWS-Per show a larger negativity (N400-like effect) elicited by phrase structure violations relative to the canonical (negative plotted up).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4318174&req=5

Fig5: N400-like mean amplitude for the Jabberwocky syntactic condition. Group mean amplitude (μV) (600–900 ms) elicited by syntactic (phrase structure) violations within Jabberwocky sentences. Averaged across central-parietal electrodes (C3, CP3, P3, CZ, CPZ, PZ, C4, CP4, and P4), only CWS-Per show a larger negativity (N400-like effect) elicited by phrase structure violations relative to the canonical (negative plotted up).
Mentions: There was no condition effect for the later (600–900 ms) negativity at medial/lateral electrodes [F(1,28) = .93, p = .34] nor at midline electrodes [F(1,28) = .00, p = .99]. However, a group × condition effect, as graphed in Figure 3, revealed differences between groups in the elicitation of a later negativity (600–900 ms) at lateral/medial electrodes [F(2,28) = 6.45, p = .01], but not midline electrodes [F(2,28) = 1.88, p = .17]. Step-down ANOVAs revealed differences between CWNS and CWS-Per [F(1,18) = 11.16, p = .004] and between CWS-Rec and CWS-Per [F(1,20) = 9.19, p = .01], but not between CWNS and CWS-Rec [F(1,18) = .01, p = .94]. Figure 5 displays a group N400-like mean amplitude averaged across central-parietal electrodes. Relative to the canonical condition, phrase structure violations elicited a negativity only for CWS-Per. However, as graphed on Figure 6, significant overlap exists in ERP elicitation across participants. This reveals considerable individual differences in neural patterns, including N400-like activity, elicited over central-parietal sites. Still, no positive activity over 5 microvolts (μV) was elicited by phrase structure violations for any of the CWS-Per participants, unlike numerous CWNS and CWS-Rec participants.Figure 5

Bottom Line: During the comprehension of English sentences, ERP activity mediating semantic and syntactic (phrase structure) processing did not distinguish CWS-Per, CWS-Rec, and CWNS.However, identical phrase structure violations within Jabberwocky sentences elicited a P600 in CWNS and CWS-Rec, but an N400-like effect in CWS-Per.Unlike CWS-Rec and CWNS, the lack of semantic context in Jabberwocky sentences seemed to affect the syntactic processing strategies of CWS-Per, resulting in the elicitation of semantically based N400-like activity during syntactic (phrase structure) violations.

View Article: PubMed Central - PubMed

Affiliation: Department of Speech, Language, and Hearing Sciences, Purdue University, Lyles-Porter Hall, 715 Clinic Drive, West Lafayette, IN 47907 USA.

ABSTRACT

Background: Characterized by the presence of involuntary speech disfluencies, developmental stuttering is a neurodevelopmental disorder of atypical speech-motor coordination. Although the etiology of stuttering is multifactorial, language development during early childhood may influence both the onset of the disorder and the likelihood of recovery. The purpose of this study was to determine whether differences in neural indices mediating language processing are associated with persistence or recovery in school-age children who stutter.

Methods: Event-related brain potentials (ERPs) were obtained from 31 6-7-year-olds, including nine children who do not stutter (CWNS), 11 children who had recovered from stuttering (CWS-Rec), and 11 children who persisted in stuttering (CWS-Per), matched for age, and all with similar socioeconomic status, nonverbal intelligence, and language ability. We examined ERPs elicited by semantic and syntactic (phrase structure) violations within an auditory narrative consisting of English and Jabberwocky sentences. In Jabberwocky sentences, content words were replaced with pseudowords to limit semantic context. A mixed effects repeated measures analysis of variance (ANOVA) was computed for ERP components with four within-subject factors, including condition, hemisphere, anterior/posterior distribution, and laterality.

Results: During the comprehension of English sentences, ERP activity mediating semantic and syntactic (phrase structure) processing did not distinguish CWS-Per, CWS-Rec, and CWNS. Semantic violations elicited a qualitatively similar N400 component across groups. Phrase structure violations within English sentences also elicited a similar P600 component in all groups. However, identical phrase structure violations within Jabberwocky sentences elicited a P600 in CWNS and CWS-Rec, but an N400-like effect in CWS-Per.

Conclusions: The distinguishing neural patterns mediating syntactic, but not semantic, processing provide evidence that specific brain functions for some aspects of language processing may be associated with stuttering persistence. Unlike CWS-Rec and CWNS, the lack of semantic context in Jabberwocky sentences seemed to affect the syntactic processing strategies of CWS-Per, resulting in the elicitation of semantically based N400-like activity during syntactic (phrase structure) violations. This vulnerability suggests neural mechanisms associated with the processing of syntactic structure may be less mature in 6-7-year-old children whose stuttering persisted compared to their fluent or recovered peers.

No MeSH data available.


Related in: MedlinePlus