Amanda Hampton Wray

Early childhood stuttering and electrophysiological indices of language processing.

UNLABELLED We examined neural activity mediating semantic and syntactic processing in 27 preschool-age children who stutter (CWS) and 27 preschool-age children who do not stutter (CWNS) matched for age, nonverbal IQ and language abilities. All participants displayed language abilities and nonverbal IQ within the normal range. Event-related brain potentials (ERPs) were elicited while participants watched a cartoon video and heard naturally spoken sentences that were either correct or contained semantic or syntactic (phrase structure) violations. ERPs in CWS, compared to CWNS, were characterized by longer N400 peak latencies elicited by semantic processing. In the CWS, syntactic violations elicited greater negative amplitudes for the early time window (150-350 ms) over medial sites compared to CWNS. Additionally, the amplitude of the P600 elicited by syntactic violations relative to control words was significant over the left hemisphere for the CWNS but showed the reverse pattern in CWS, a robust effect only over the right hemisphere. Both groups of preschoolage children demonstrated marked and differential effects for neural processes elicited by semantic and phrase structure violations; however, a significant proportion of young CWS exhibit differences in the neural functions mediating language processing compared to CWNS despite normal language abilities. These results are the first to show that differences in event-related brain potentials reflecting language processing occur as early as the preschool years in CWS and provide the first evidence that atypical lateralization of hemispheric speech/language functions previously observed in the brains of adults who stutter begin to emerge near the onset of developmental stuttering. EDUCATIONAL OBJECTIVES The reader will be able to: (1) describe the role of language processing in current theoretical models of developmental stuttering; (2) summarize current evidence regarding language processing differences between individuals who do and do not stutter; (3) describe typical changes in neural indices of semantic and syntactic processing across development; (4) discuss the potential implications of the current findings in relation to theories of developmental stuttering.

Electrophysiological Correlates of Rapid Auditory and Linguistic Processing in Adolescents with Specific Language Impairment

Brief tonal stimuli and spoken sentences were utilized to examine whether adolescents (aged 14;3-18;1) with specific language impairments (SLI) exhibit atypical neural activity for rapid auditory processing of non-linguistic stimuli and linguistic processing of verb-agreement and semantic constraints. Further, we examined whether the behavioral and electrophysiological indices for rapid auditory processing were correlated with those for linguistic processing. Fifteen adolescents with SLI and 15 adolescents with normal language met strict criteria for displaying consistent diagnoses from kindergarten through the eighth grade. The findings provide evidence that auditory processing for non-linguistic stimuli is atypical in a significant number of adolescents with SLI compared to peers with normal language and indicate that reduced efficiency in auditory processing in SLI is more vulnerable to rapid rates (200ms ISI) of stimuli presentation (indexed by reduced accuracy, a tendency for longer RTs, reduced N100 over right anterior sites, and reduced amplitude P300). Many adolescents with SLI displayed reduced behavioral accuracy for detecting verb-agreement violations and semantic anomalies, along with less robust P600s elicited by verb-agreement violations. The results indicate that ERPs elicited by morphosyntactic aspects of language processing are atypical in many adolescents with SLI. Additionally, correlational analyses between behavioral and electrophysiological indices of processing non-linguistic stimuli and verb-agreement violations suggest that the integrity of neural functions for auditory processing may only account for a small proportion of the variance in morphosyntactic processing in some adolescents.

Non-Linguistic Auditory Processing and Working Memory Update in Pre-School Children Who Stutter: An Electrophysiological Study

Non-linguistic auditory processing and working memory update were examined with event-related potentials (ERPs) in 18 children who stutter (CWS) and 18 children who do not stutter (CWNS). Children heard frequent 1 kHz tones interspersed with rare 2 kHz tones. The two groups did not differ on any measure of the P1 and N1 components, strongly suggesting that early auditory processing of pure tones is unimpaired in CWS. However, as a group, only CWNS exhibited a P3 component to rare tones, suggesting that developmental stuttering may be associated with a less efficient attentional allocation and working memory update in response to auditory change.

Specific aspects of cognitive and language proficiency account for variability in neural indices of semantic and syntactic processing in children.

The neural activity mediating language processing in young children is characterized by large individual variability that is likely related in part to individual strengths and weakness across various cognitive abilities. The current study addresses the following question: How does proficiency in specific cognitive and language functions impact neural indices mediating language processing in children? Thirty typically developing seven- and eight-year-olds were divided into high-normal and low-normal proficiency groups based on performance on nonverbal IQ, auditory word recall, and grammatical morphology tests. Event-related brain potentials (ERPs) were elicited by semantic anomalies and phrase structure violations in naturally spoken sentences. The proficiency for each of the specific cognitive and language tasks uniquely contributed to specific aspects (e.g., timing and/or resource allocation) of neural indices underlying semantic (N400) and syntactic (P600) processing. These results suggest that distinct aptitudes within broader domains of cognition and language, even within the normal range, influence the neural signatures of semantic and syntactic processing. Furthermore, the current findings have important implications for the design and interpretation of developmental studies of ERPs indexing language processing, and they highlight the need to take into account cognitive abilities both within and outside the classic language domain.

Development of selective attention in preschool-age children from lower socioeconomic status backgrounds

Highlights • We assessed selective attention in 4-year-olds from lower & higher SES backgrounds.• Development of selective attention over one year was evaluated in the LSES group.• At age four, only the HSES group showed enhanced neural responses with attention.• The LSES group developed an effect of attention on neural processing by age five.• The LSES group showed persistent attenuation of distractor suppression at age five.

5-HTTLPR polymorphism is linked to neural mechanisms of selective attention in preschoolers from lower socioeconomic status backgrounds

Highlights • We investigated associations between 5-HTTLPR genotypes and selective attention.• Lower SES children aged 3–5 completed an ERP selective attention task.• Children with at least one short 5-HTTLPR allele had larger ERP attention effects.• The short allele is linked to enhanced neural mechanisms of attention in children.• This lays the groundwork for gene-by-environment studies involving cognitive skills.

Neuroplasticity of selective attention: Research foundations and preliminary evidence for a gene by intervention interaction

Significance Selective attention is the ability to select and preferentially process specific information while simultaneously suppressing the processing of irrelevant, competing distractors. It is a fundamental ability linked to various cognitive skills and academic achievement. We describe the foundations and history of our research program, which spans from basic research on neural mechanisms and neuroplasticity of selective attention to translational research aimed at designing interventions to improve selective attention. We also present preliminary evidence for gene × intervention interactions in neural mechanisms of selective attention in children from lower socioeconomic status backgrounds. This program of research demonstrates the marked malleability of neural systems for selective attention and highlights the potential for changes in selective attention as a function of intervention. This article reviews the trajectory of our research program on selective attention, which has moved from basic research on the neural processes underlying selective attention to translational studies using selective attention as a neurobiological target for evidence-based interventions. We use this background to present a promising preliminary investigation of how genetic and experiential factors interact during development (i.e., gene × intervention interactions). Our findings provide evidence on how exposure to a family-based training can modify the associations between genotype (5-HTTLPR) and the neural mechanisms of selective attention in preschool children from lower socioeconomic status backgrounds.

Neural Indices of Semantic Processing in Early Childhood Distinguish Eventual Stuttering Persistence and Recovery

Purpose Maturation of neural processes for language may lag in some children who stutter (CWS), and event-related potentials (ERPs) distinguish CWS who have recovered from those who have persisted. The current study explores whether ERPs indexing semantic processing may distinguish children who will eventually persist in stuttering (CWS-ePersisted) from those who will recover from stuttering (CWS-eRecovered). Method Fifty-six 5-year-old children with normal receptive language listened to naturally spoken sentences in a story context. ERP components elicited for semantic processing (N400, late positive component [LPC]) were compared for CWS-ePersisted, CWS-eRecovered, and children who do not stutter (CWNS). Results The N400 elicited by semantic violations had a more focal scalp distribution (left lateralized and less anterior) in the CWS-eRecovered compared with CWS-ePersisted. Although the LPC elicited in CWS-eRecovered and CWNS did not differ, the LPC elicited in the CWS-ePersisted was smaller in amplitude compared with that in CWNS. Conclusions ERPs elicited in 5-year-old CWS-eRecovered compared with CWS-ePersisted suggest that future recovery from stuttering may be associated with earlier maturation of semantic processes in the preschool years. Subtle differences in ERP indices offer a window into neural maturation processes for language and may help distinguish the course of stuttering development.

Creating Connections Between Researchers and Educators

ABSTRACT Translational research involving the development, implementation, and assessment of evidence-based interventions has shown promise in improving outcomes for children from lower socioeconomic-status backgrounds. One such approach involves 2-generation interventions, which target both children and their parents/caregivers. Here we traced the evolution of a 15-year partnership between researchers from the University of Oregon Brain Development Lab and educators from Head Start of Lane County, with a primary goal of developing, implementing, and evaluating a 2-generation intervention. The partnership has produced a successful 2-generation intervention, with current efforts focused on the development of a scaled-up delivery model that can be implemented by Head Start staff and integrated into existing Head Start structure classrooms. Taking a “lessons-learned” approach and including the perspectives of researchers and educators, we highlight 4 key themes that emerged from this partnership and may be useful to other researchers collaborating with educators to develop evidence-based interventions: 1) employ smaller-scale studies that trade ecological validity for experimental control to establish a proof of concept, 2) adapt to real-world constraints when scaling for broader implementation, 3) consider theoretical insights from smaller-scale studies when developing scalable delivery models, and 4) work together to find novel solutions to common problems. We close with results from a survey of teachers involved in the project, a broad reflection on successes of the collaboration, and a discussion on focusing efforts to sustain the intervention in the future.