Unique associations in hierarchical regression analyses were demonstrated between VWM at age two years and receptive and expressive language skills at age four, and between early processing speed and later receptive language. However, early PSTM did not predict unique variance in language outcomes, as it shared variance with other measures.
These findings confirm previous research positing a strong role for phonological short-term memory in early expressive vocabulary acquisition. They also extend previous research in two ways. First, a unique association between verbal working memory and expressive vocabulary in 2-year-olds was observed. Second, processing speed was not a unique predictor of variance in expressive vocabulary when included alongside measures of working memory.
Purpose
This article first aimed to examine the cognitive (rapid automatized naming, phonological awareness, working memory, nonverbal cognition, and language) correlates of reading difficulty in children with language impairment (LI). Second, we considered whether noncognitive (effortful control, social competence, and behavior problems) correlates offered any explanatory value above that of cognitive factors. Third, we examined whether home environment (specifically household organization and home learning environment) would offer an additional explanatory value.
Method
The sample included 165 children in kindergarten and Grade 1 who were receiving intervention for LI in public schools. Standardized measures along with parent interviews/questionnaires were administered at the end of the school year.
Results
Logistic regression models indicated the noncognitive factors added discriminatory value to that of cognitive factors in predicting reading difficulties, whereas household factors did not. In the final model using all 11 predictors, prediction accuracy was 88.7% for the typical reading group and 54.2% for the reading difficulty group, with an overall accuracy of 76.4%. Only phonological awareness and working memory significantly contributed to predicting reading group membership when measured in kindergarten and Grade 1.
Conclusions
For this sample of children with LI, the most important predictors of reading were cognitive. The child's behavior and social competence improved prediction to a limited but statistically significant degree, whereas home environment did not. Overall classification was low, as only half of the children with reading difficulties were correctly predicted. Important factors differentiating good and poor emergent readers with LI were not captured in this study.
Supplemental Material
https://doi.org/10.23641/asha.12462428
Background: Previous studies have explored the size and word type composition (nouns, predicates, etc.) of expressive vocabularies of preschool children with Down syndrome, both spoken and signed. Separately, overall preferences for modality of expression have also been explored. Aims: To extend previous findings by describing the relationships between expressive vocabulary size and both word type and modality of expression in the preschool period including changes to modality preference over time.
Methods& Procedures: Mothers of 35 children with Down syndrome, aged 36-66 months and attending the same early intervention programme, completed a version -with both spoken word and sign options -of the New Zealand MacArthur-Bates Communicative Development Inventory (CDI): Words and Sentences. Most mothers completed the CDI on multiple occasions across the duration of the study. Completions (n = 114) were analysed cross-sectionally and longitudinally in terms of (1) word type relative to vocabulary size, (2) modality of expression relative to word type and vocabulary size, and (3) individual trajectories in vocabulary size and modality of expression.
Outcomes & Results:(1) Word type relative to vocabulary size was similar to previous studies with a greater proportion of the SOCIAL words being present in the children's vocabularies throughout, followed by NOUNS, PREDICATES and CLOSED class words, with proportions converging as vocabulary sizes increase.(2) An initial spoken word preference for SOCIAL and CLOSED class words and sign preference for NOUNS and PREDICATES was found, with more spoken words in larger vocabularies overall. (3) Individual trajectories were highly variable and also revealed temporary points of regression in overall expressive vocabulary size in some children. Children who shifted from reliance on sign to predominantly spoken word expression did so at different ages and at different vocabulary sizes. At school entry, while most of the children used bothThis is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
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