Genome-wide association analyses of individual differences in quantitatively assessed reading- and language-related skills in up to 34,000 people

The use of spoken and written language is a capacity that is unique to humans. Individual differences in reading- and language-related skills are influenced by genetic variation, with twin-based heritability estimates of 30-80%, depending on the trait. The relevant genetic architecture is complex, heterogeneous, and multifactorial, and yet to be investigated with well-powered studies. Here, we present a multicohort genome-wide association study (GWAS) of five traits assessed individually using psychometric measures: word reading, nonword reading, spelling, phoneme awareness, and nonword repetition, with total sample sizes ranging from 13,633 to 33,959 participants aged 5-26 years (12,411 to 27,180 for those with European ancestry, defined by principal component analyses). We identified a genome-wide significant association with word reading (rs11208009, p=1.098 x 10-8) independent of known loci associated with intelligence or educational attainment. All five reading-/language-related traits had robust SNP-heritability estimates (0.13-0.26), and genetic correlations between them were modest to high. Using genomic structural equation modelling, we found evidence for a shared genetic factor explaining the majority of variation in word and nonword reading, spelling, and phoneme awareness, which only partially overlapped with genetic variation contributing to nonword repetition, intelligence and educational attainment. A multivariate GWAS was performed to jointly analyse word and nonword reading, spelling, and phoneme awareness, maximizing power for follow-up investigation. Genetic correlation analysis of multivariate GWAS results with neuroimaging traits identified association with cortical surface area of the banks of the left superior temporal sulcus, a brain region with known links to processing of spoken and written language. Analysis of evolutionary annotations on the lineage that led to modern humans showed enriched heritability in regions depleted of Neanderthal variants. Together, these results provide new avenues for deciphering the biological underpinnings of these uniquely human traits.

Examining the growth trajectories and cognitive predictors of reading in a consistent orthography: Evidence from a 10-year longitudinal study

We examined the growth trajectories of reading in a consistent orthography (Greek) in two developmental periods (from Grade 1 to Grade 4 and from Grade 4 to Grade 10) and what cognitive skills predict the growth patterns. Seventy-five Greek-speaking children were assessed in Grades 1, 2, 4, 6, and 10 on word-, nonword-, and text-reading fluency. In Grades 1 and 4, they were also assessed on phonological awareness, rapid naming, phonological memory, orthographic knowledge, and articulation rate. Results of growth curve modeling showed that during the first developmental period, there was a rapid initial growth from Grade 1 to Grade 2 followed by a less rapid growth from Grade 2 to Grade 4. In the second developmental period, the slow growth continued. In both developmental periods, rapid naming and orthographic knowledge predicted the initial status of all reading outcomes and phonological memory predicted the initial status of nonword-reading fluency. Phonological awareness predicted the initial status of nonword-reading fluency in the first developmental period and the initial status of word- and text-reading fluency in the second developmental period. None of the cognitive skills predicted the growth rate in reading skills. Theoretical and practical implications of these findings are discussed.

Are people consistent when reading nonwords aloud on different occasions?

Tests of nonword reading have been instrumental in adjudicating between theories of reading and in assessing individuals’ reading skill in educational and clinical practice. It is generally assumed that the way in which readers pronounce nonwords reflects their long-term knowledge of spelling–sound correspondences that exist in the writing system. The present study found considerable variability in how the same adults read the same 50 nonwords across five sessions. This variability was not all random: Nonwords that consisted of graphemes that had multiple possible pronunciations in English elicited more intraparticipant variation. Furthermore, over time, shifts in participants’ responses occurred such that some pronunciations became used more frequently, while others were pruned. We discuss possible mechanisms by which session-to-session variability arises and implications that our findings have for interpreting snapshot-based studies of nonword reading. We argue that it is essential to understand mechanisms underpinning this session-to-session variability in order to interpret differences across individuals in how they read nonwords aloud on a single occasion.

NEURAL CORRELATES OF WORD AND NONWORD READING PROCESSES IN TYPICAL AGING: A FNIRS STUDY

Backgroud: Phonological and lexical-semantic processes in the elderly population still needed be investigate specially to understand how neural plasticity and compensatory mechanisms influence these processes. Objective: The functional near-infrared spectroscopy (fNIRS) has been increasingly used in language studies to observe cortical activity. Methods: In the current study, we characterize the performance of this population in naming and reading tasks and explore their neural correlates. 32 healthy elderly adults (age 69.1±5.9) performed word/nonword reading aloud and oral naming tasks, with concomitant fNIRS recording. We compared task condition vs rest blocks in anterior and posterior temporal (ATC, PTC), dorsolateral prefrontal (dlPFC), inferior frontal (IFC) and inferior parietal (IPC) cortices, bilaterally. Results: We found lexicality and regularity effects modulating word reading fluency (p <.001). No difference was observed in naming and nonword fluency. We observed cortical activity only in dlPFC for nonword, in ATC and PTC for irregular words, in dlPFC and PTC for regular words and in dlPFC and IPC for naming (p<.05). No lateralization was observed in any condition. We verified a positive correlation between reading fluency and dlPFC activity (p <.02). Conclusion: Our findings supporting the dual-route models and indicate compensatory neural mechanisms in aging.

Comparing the Effects of Reading Intervention Versus Reading and Mindset Intervention for Upper Elementary Students With Reading Difficulties

The primary purpose of this study was to examine the effects of providing mindset intervention in addition to reading intervention compared with only reading intervention for fourth graders with reading difficulties. Reading intervention was provided daily in 45 min sessions throughout the school year. Mindset intervention occurred in small groups for 24–30 min lessons. Multilevel structural equation modeling (SEM) via n-level SEM was used to account for the latent variable representation of constructs, and the complex nesting and cross-classification structure of the data. Students in the reading intervention plus mindset condition significantly outperformed the business as usual condition on nonword reading ( d = 0.35) as did students in the reading intervention condition ( d = 0.20), who also outperformed the business as usual condition on phonological processing ( d = 0.28). There were no significant differences among students in the three conditions on nonword reading, word reading, phonological processing, reading comprehension, or growth mindset. Initial reading achievement, mindset, and problem behavior did not generally moderate these findings.

A small group intervention for older primary school-aged low-progress readers: Further evidence for efficacy

The aim of the present study was to determine the efficacy of a small-group reading instruction program that was delivered over two school terms to Australian students in Years 3 through 6. A large cohort (n = 239) of primary school children was assessed on their literacy skills before and after receiving ‘MacqLit’, a phonics-based program designed for older struggling readers. Parametric and nonparametric difference tests were used to compare results at pre- and postintervention time points. Statistically significant improvements with large effect sizes were observed on all raw score measures of word reading, nonword reading, passage reading and spelling. Statistically significant improvements were also observed on standard score measures of nonword reading and passage reading, suggesting the gains were greater than what might be expected to have resulted from typical classroom instruction. The results indicate that older middle primary school-aged students may benefit from phonics-based, small-group reading instruction.