Shortened Nonword Repetition Task (NWR-S): A Simple, Quick, and Less Expensive Outcome to Identify Children With Combined Specific Language and Reading Impairment

Using Nonword Repetition to Identify Developmental Language Disorder in Monolingual and Bilingual Children: A Systematic Review and Meta-Analysis

Purpose A wealth of studies has assessed the diagnostic value of the nonword repetition task (NWRT) for the detection of developmental language disorder (DLD) in the clinical context of speech and language therapy, first in monolingual children and, more recently, in bilingual children. This review article reviews this literature systematically and conducts a meta-analysis on the discriminative power of this type of task in both populations. Method Three databases were used to select articles based on keyword combinations, which were then reviewed for relevance and methodological rigor based on internationally recognized checklists. From an initial pool of 488 studies, 46 studies were selected for inclusion in the systematic review, and 35 of these studies could be included in a meta-analysis. Results Most of the articles report significant discrimination between children with and without DLD in both monolingual and bilingual contexts, and the meta-analysis shows a large mean effect size. Three factors (age of the child, linguistic status, and language specificity of the task) yielded enough quantitative data for further exploration. Subgroups analysis shows variance in effect sizes, but none of the three factors, neither their interactions, were significant in a metaregression. We discuss how other, less explored factors (e.g., nature of the stimuli, scoring methods) could also contribute to differences in results. Sensitivity and specificity analyses reported in 33 studies confirmed that, despite possible effect size differences, the diagnostic accuracy of the NWRT is generally near thresholds considered to be discriminatory. It generally increases when it is combined with other tasks (e.g., parental questionnaire). Conclusions This review indicates that the NWRT is a promising diagnostic tool to identify children with DLD in monolingual and bilingual contexts with a large mean effect size. However, it seems necessary to choose the precise NWRT materials based on the children's language background and to complement the assessment sessions with other tools in order to ensure diagnosis and to obtain complete language profile of the child. Supplemental Material https://doi.org/10.23641/asha.15152370.

The contribution of individual differences in statistical learning to reading and spelling performance in children with and without dyslexia

Using an individual differences approach in children with and without dyslexia, this study investigated the hypothesized relationship between statistical learning ability and literacy (reading and spelling) skills. We examined the clinical relevance of statistical learning (serial reaction time and visual statistical learning tasks) by controlling for potential confounds at the participant level (e.g., non-verbal reasoning, attention and phonological skills including rapid automatized naming and phonological short-term memory). A 100 Dutch-speaking 8- to 11-year-old children with and without dyslexia participated (50 per group), see also van Witteloostuijn et al. (2019) for a study with the same participants. No evidence of a relationship between statistical learning and literacy skills is found above and beyond participant-level variables. Suggestions from the literature that the link between statistical learning and literacy attainment, and therefore its clinical relevance, might be small and strongly influenced by methodological differences between studies are not contradicted by our findings.

Developmental Language Disorder and Uninhibited Primitive Reflexes in Young Children

Purpose Developmental language disorder (DLD) is a developmental disorder where children fail to acquire language in the absence of a clear cause. Many studies have reported general motor deficits in children with DLD, but no studies have uncovered a cure. The purpose of our study is to better understand the underlying motor deficits in DLD, starting from uninhibited primary reflexes-which are the most basic stage of motor development. Knowledge of this motor-language relationship should lead to earlier and more targeted interventions in young children with DLD. Method Children with DLD (n = 75, age range: 4-10 years) and 99 age-matched typically developing (TD) children completed a nonword repetition test to assess DLD and six other tests to assess primitive reflexes. Results Children with DLD demonstrated higher levels of persistent primitive reflexes compared to TD children. As the scores for neuromotor immaturity increased, nonword repetition test scores decreased (r = -.44, p < .01). Results indicated that TD children exhibited lower neuromotor immaturity (M = 7.63, SD = 3.75) compared to children with DLD (M = 13.51, SD = 4.47). All primitive reflexes (the Moro reflex, the symmetrical tonic neck reflex in flexion and in extension, the asymmetrical tonic neck reflex, the tonic labyrinthine reflex, and the Galant reflex) turned out to be statistically significantly different for the TD and DLD groups (p < .001). We also observed some differences between sexes. Conclusions Children with impaired language development underwent slower neuromotor development. However, further research is needed to determine whether motor intervention programs that inhibit primitive reflexes are helpful for children with DLD.

Identifying interactive biological pathways associated with reading disability

INTRODUCTION

Past research has suggested that reading disability is a complex disorder involving genetic and environment contributions, as well as gene-gene and gene-environment interaction, but to date little is known about the underlying mechanisms.

METHOD

Using the Avon Longitudinal Study of Parents and Children, we assessed the contributions of genetic, demographic, and environmental variables on case-control status using machine learning. We investigated the functional interactions between genes using pathway and network analysis.

RESULTS

Our results support a systems approach to studying the etiology of reading disability with many genes (e.g., RAPGEF2, KIAA0319, DLC1) and biological pathways (e.g., neuron migration, positive regulation of dendrite regulation, nervous system development) interacting with each other. We found that single nucleotide variants within genes often had opposite effects and that enriched biological pathways were mediated by neuron migration. We also identified behavioral (i.e., receptive language, nonverbal intelligence, and vocabulary), demographic (i.e., mother's highest education), and environmental (i.e., birthweight) factors that influenced case-control status when accounting for genetic information.

DISCUSSION

The behavioral and demographic factors were suggested to be protective against reading disability status, while birthweight conveyed risk. We provided supporting evidence that reading disability has a complex biological and environmental etiology and that there may be a shared genetic and neurobiological architecture for reading (dis)ability.