The Home Literacy Environment as a Predictor of the Early Literacy Development of Children at Family-Risk of Dyslexia

The home literacy environment (HLE) predicts language and reading development in typically developing children; relatively little is known about its association with literacy development in children at family-risk of dyslexia. We assessed the HLE at age 4 years, precursor literacy skills at age 5, and literacy outcomes at age 6, in a sample of children at family-risk of dyslexia (n = 116) and children with no known risk (n = 72). Developmental relationships between the HLE and literacy were comparable between the groups; an additional effect of storybook exposure on phoneme awareness was observed in the family-risk group only. The effects of socioeconomic status on literacy were partially mediated by variations in the HLE; in turn, effects of the HLE on literacy were mediated by precursor skills (oral language, phoneme awareness, and emergent decoding) in both groups. Findings are discussed in terms of possible gene–environment correlation mechanisms underpinning atypical literacy development

Language impairment from 4 to 12 years : : prediction and etiology

PURPOSE The authors of this article examined the etiology of developmental language impairment (LI) at 4 and 12 years of age, as well as the relationship between the 2. METHOD Phenotypic and quantitative genetic analyses using longitudinal data from the Twins Early Development Study (Oliver & Plomin, 2007) were conducted. A total of 2,923 pairs of twins (1,075 monozygotic [MZ]; 975 dizygotic same sex [DZss]; and 873 dizygotic opposite sex [DZos]) provided data at 4 and 12 years. At 4 years, (a) psychometric LI was defined on the basis of a low parent-reported expressive vocabulary score (-1.25 SDs; 226 MZ and 115 DZss probands for genetic analysis); and (b) parent referral was defined as having seen a medical professional or speech-language pathologist following parental concern (112 MZ and 104 DZss probands). The 12-year language measure was a composite of 4 web-administered receptive language tests. RESULTS (a) Psychometric LI at 4 years is more predictive than parent referral of poor language performance at age 12 years, and (b) parent referral is substantially and significantly more heritable than psychometric LI. CONCLUSIONS Parents' concern about their child's language development seems to be the marker of a more heritable disorder than poor expressive language skills alone. However, the language difficulties that arouse parental concern in preschool children, although more heritable, are not predictive of language difficulties in early adolescence. Rather, poor expressive language skills at age 4 years, psychometrically defined, are a better predictor than parent referral of continuing language difficulties at age 12 years

Shared storybook reading with children at family risk of dyslexia

Background: Shared storybook reading is an important context for language learning and often constitutes young children's first encounter with the printed word. The quality of early shared reading interactions is a known predictor of language and reading development, but few studies have examined these interactions in children at family risk of dyslexia. Methods: This exploratory study describes the quality of shared storybook reading between mothers and their 3- to 4-year-old children at family risk of dyslexia (FR; n = 18) in comparison with dyads with no known risk (no-FR; n = 13). Mother–child interactions while sharing a familiar and an unfamiliar storybook were coded for type of extra-textual talk (meaning-related talk at the concrete and abstract levels; print-related talk) and affective quality. Maternal and child language and literacy skills were considered as potential correlates of shared reading quality. Results: The linguistic and affective quality of shared reading was broadly comparable across FR and no-FR dyads, particularly when sharing a book they knew well, with large within-group variation. Mothers contributed more concrete meaning-related talk when introducing an unfamiliar book to their children; children contributed more extra-textual talk overall when sharing a familiar book. Maternal language, but not reading, skills were related to the linguistic quality of shared reading. The affective quality of reading interactions was rated more highly in dyads where mothers and children had stronger language skills. Conclusions: These results suggest that the quality of shared reading does not vary systematically as a function of children's risk of dyslexia but is related to maternal language skills. This finding needs to be replicated in a larger sample in order to better understand the risk and protective factors associated with dyslexia. Highlights: What is already known about this topic The quality of extra-textual talk during shared reading between parents and preschoolers predicts later language and literacy outcomes in typically developing children. The affective quality of early shared reading predicts children's motivation to read independently in later childhood. Children at family risk of dyslexia are more likely than their peers with no family risk to have difficulty learning to read and may show weaknesses in oral language skills. What this paper adds. The linguistic and affective quality of shared reading between mothers and preschool children is broadly similar when children are at family risk of dyslexia compared with no family risk. The type and quantity of extra-textual talk contributed by mothers and children appears to differ according to the familiarity of the storybook, but replication of the findings in a larger sample is required. The linguistic and affective quality of shared reading is related to maternal language skills. Implications for theory, policy or practice. Shared storybook reading offers rich language learning opportunities for children at family risk of dyslexia. Maternal language skills may be an important determinant of the interactional quality of shared reading. The linguistic and affective quality of shared reading is not clearly associated with maternal reading difficulties

Limited Evidence of an Association Between Language, Literacy, and Procedural Learning in Typical and Atypical Development : A Meta-Analysis

The ability to extract patterns from sensory input across time and space is thought to underlie the development and acquisition of language and literacy skills, particularly the subdomains marked by the learning of probabilistic knowledge. Thus, impairments in procedural learning are hypothesized to underlie neurodevelopmental disorders, such as dyslexia and developmental language disorder. In the present meta-analysis, comprising 2396 participants from 39 independent studies, the continuous relationship between language, literacy, and procedural learning on the Serial Reaction Time task (SRTT) was assessed across children and adults with typical development (TD), dyslexia, and Developmental Language Disorder (DLD). Despite a significant, but very small, relationship between procedural learning and overall language and literacy measures, this pattern was not observed at the group-level when examining TD, dyslexic, and DLD groups separately. Based on the procedural/declarative model, a positive relationship was expected between procedural learning and language and literacy measures for the typically developing group; however, no such relationship was observed. This was also the case for the disordered groups (ps > .05). Also counter to expectations, the magnitude of the relationship between procedural learning and grammar and phonology did not differ between TD and DLD (ps > .05), nor between the TD and dyslexic group on reading, spelling, and phonology (ps > .05). While lending little support to the procedural/declarative model, we consider that these results may be the consequence of poor psychometric properties of the SRTT as a measure of procedural learning

The reliability of the serial reaction time task : meta-analysis of test-retest correlations

The Serial Reaction Time task, one of the most widely used tasks to index procedural memory, has been increasingly employed in individual differences research examining the role of procedural memory in language and other cognitive abilities. Yet, despite consistently producing robust procedural learning effects at the group level (i.e. faster responses to sequenced/probable trials versus random/improbable trials), these effects have recently been found to have poor reliability. In this meta-analysis ( N = 7), comprising 719 participants ( M = 20.81, s.d. = 7.13), we confirm this 'reliability paradox'. The overall retest reliability of the robust procedural learning effect elicited by the SRTT was found to be well below acceptable psychometric standards ( r < 0.40). However, split-half reliability within a session is better, with an overall estimate of 0.66. There were no significant effects of sampling (participants' age), methodology (e.g. number of trials, sequence type) and analytical decisions (whether all trials were included when computing the procedural learning scores; using different indexes of procedural learning). Thus, despite producing robust effects at the group-level, until we have a better understanding of the factors that improve the reliability of this task using the SRTT for individual differences research should be done with caution

Genome-wide association study of receptive language ability of 12 year olds

Purpose: We have previously shown that individual differences in measures of receptive language ability at age 12 are highly heritable. The current study attempted to identify some of the genes responsible for the heritability of receptive language ability using a genome-wide association (GWA) approach. Method: We administered four internet-based measures of receptive language (vocabulary, semantics, syntax, and pragmatics) to a sample of 2329 12-year-olds for whom DNA and genome-wide genotyping were available. Nearly 700,000 single-nucleotide polymorphisms (SNPs) and one million imputed SNPs were included in a GWA analysis of receptive language composite scores. Results: No SNP associations met the demanding criterion of genome-wide significance that corrects for multiple testing across the genome (p < 5 ×10-8). The strongest SNP association did not replicate in an additional sample of 2639 12-year-olds. Conclusion: These results indicate that individual differences in receptive language ability in the general population do not reflect common genetic variants that account for >3% of the phenotypic variance. The search for genetic variants associated with language skill will require larger samples and additional methods to identify and functionally characterize the full spectrum of risk variants

Disentangling genetic and environmental influences on early language development: The interplay of genetic propensity for negative emotionality and surgency, and parenting behavior effects on early language skills in an adoption study

Parenting and children's temperament are important influences on language development. However, temperament may reflect prior parenting, and parenting effects may reflect genes common to parents and children. In 561 U.S. adoptees (57% male) and their birth and rearing parents (70% and 92% White, 13% and 4% African American, and 7% and 2% Latinx, respectively), this study demonstrated how genetic propensity for temperament affects language development, and how this relates to parenting. Genetic propensity for negative emotionality inversely predicted language at 27 months (β = −.15) and evoked greater maternal warmth (β = .12), whereas propensity for surgency positively predicted language at 4.5 years (β = .20), especially when warmth was low. Parental warmth (β = .15) and sensitivity (β = .19) further contributed to language development, controlling for common gene effects

Language and reading impairments are associated with increased prevalence of non-right handedness

Funding: Royal Society - UF150663, RGF\EA\180141; Wellcome Trust - 217065/Z/19/Z; H2020 European Research Council - 694189; NWO - 451-15-017; National Health and Medical Research Council - 1173896; Canadian Institute for Health Research - MOP-133440.Handedness has been studied for association with language-related disorders because of its link with language hemispheric dominance. No clear pattern has emerged, possibly because of small samples, publication bias, and heterogeneous criteria across studies. Non-right-handedness (NRH) frequency was assessed in N = 2503 cases with reading and/or language impairment and N = 4316 sex-matched controls identified from 10 distinct cohorts (age range 6–19 years old; European ethnicity) using a priori set criteria. A meta-analysis (Ncases = 1994) showed elevated NRH % in individuals with language/reading impairment compared with controls (OR = 1.21, CI = 1.06–1.39, p = .01). The association between reading/language impairments and NRH could result from shared pathways underlying brain lateralization, handedness, and cognitive functions.Publisher PDFPeer reviewe

Further evidence for a parent-of-origin effect at the NOP9 locus on language-related phenotypes

Background - Specific language impairment (SLI) is a common neurodevelopmental disorder, observed in 5–10 % of children. Family and twin studies suggest a strong genetic component, but relatively few candidate genes have been reported to date. A recent genome-wide association study (GWAS) described the first statistically significant association specifically for a SLI cohort between a missense variant (rs4280164) in the NOP9 gene and language-related phenotypes under a parent-of-origin model. Replications of these findings are particularly challenging because the availability of parental DNA is required. Methods - We used two independent family-based cohorts characterised with reading- and language-related traits: a longitudinal cohort (n = 106 informative families) including children with language and reading difficulties and a nuclear family cohort (n = 264 families) selected for dyslexia. Results - We observed association with language-related measures when modelling for parent-of-origin effects at the NOP9 locus in both cohorts: minimum P = 0.001 for phonological awareness with a paternal effect in the first cohort and minimum P = 0.0004 for irregular word reading with a maternal effect in the second cohort. Allelic and parental trends were not consistent when compared to the original study. Conclusions - A parent-of-origin effect at this locus was detected in both cohorts, albeit with different trends. These findings contribute in interpreting the original GWAS report and support further investigations of the NOP9 locus and its role in language-related traits. A systematic evaluation of parent-of-origin effects in genetic association studies has the potential to reveal novel mechanisms underlying complex traits

Language and reading impairments are associated with increased prevalence of non‐right‐handedness

Handedness has been studied for association with language‐related disorders because of its link with language hemispheric dominance. No clear pattern has emerged, possibly because of small samples, publication bias, and heterogeneous criteria across studies. Non‐right‐handedness (NRH) frequency was assessed in N = 2503 cases with reading and/or language impairment and N = 4316 sex‐matched controls identified from 10 distinct cohorts (age range 6–19 years old; European ethnicity) using a priori set criteria. A meta‐analysis (Ncases = 1994) showed elevated NRH % in individuals with language/reading impairment compared with controls (OR = 1.21, CI = 1.06–1.39, p = .01). The association between reading/language impairments and NRH could result from shared pathways underlying brain lateralization, handedness, and cognitive functions