Genome-wide 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 fundamental human capacity. Individual differences in reading- and language-related skills are influenced by genetic variation, with twin-based heritability estimates of 30 to 80% depending on the trait. The genetic architecture is complex, heterogeneous, and multifactorial, but investigations of contributions of single-nucleotide polymorphisms (SNPs) were thus far underpowered. 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) in samples of 13,633 to 33,959 participants aged 5 to 26 y. We identified genome-wide significant association with word reading (rs11208009, P = 1.098 × 10-8) at a locus that has not been associated with intelligence or educational attainment. All five reading-/language-related traits showed robust SNP heritability, accounting for 13 to 26% of trait variability. Genomic structural equation modeling revealed a shared genetic factor explaining most of the variation in word/nonword reading, spelling, and phoneme awareness, which only partially overlapped with genetic variation contributing to nonword repetition, intelligence, and educational attainment. A multivariate GWAS of word/nonword reading, spelling, and phoneme awareness maximized power for follow-up investigation. Genetic correlation analysis with neuroimaging traits identified an association with the surface area of the banks of the left superior temporal sulcus, a brain region linked to the processing of spoken and written language. Heritability was enriched for genomic elements regulating gene expression in the fetal brain and in chromosomal regions that are depleted of Neanderthal variants. Together, these results provide avenues for deciphering the biological underpinnings of uniquely human traits.

Presentation matters: Surface text features and text quality in written narratives of Dutch high school students with and without dyslexia.

Presentation features such as spelling, punctuation and handwriting can influence the evaluation of general text quality. High school students with dyslexia might therefore be at a disadvantage, as at least their spelling performance is typically poor(er). Furthermore, these students might show less sophisticated linguistic features of texts, such as word length and sentence complexity, that might also be related to text quality. We compared narratives written by Dutch high school students (mean age 13.7 years) with (n = 28) and without (n = 29) dyslexia. Students with dyslexia's texts contained more spelling errors and poorer handwriting quality, but not more punctuation errors. Teacher-rated general text quality was lower for the texts of students with dyslexia in uncorrected versions. When spelling and punctuation errors were corrected, no teacher-rated text quality differences emerged. No differences in linguistic text features were found. Furthermore, spelling, punctuation and, to a lesser extent, number of words per sentence clause were related to ratings of text quality across participants. These results confirm the influence of presentation features on text quality rating. They encourage teachers to be aware of this effect and emphasize the importance of spelling and writing support and interventions for students with dyslexia throughout education.

A stitch in time : Comparing late-identified, late-emerging and early-identified dyslexia.

When dyslexia is diagnosed late, the question is whether this is due to late-emerging (LE) or late-identified (LI) problems. In a random selection of dyslexia-diagnosis case files we distinguished early-diagnosed (Grade 1-3, n = 116) and late-diagnosed (Grade 4-6) dyslexia. The late-diagnosed files were divided into LE (n = 54) and LI dyslexia (n = 45). The LE group consisted of children whose national-curriculum literacy outcomes did not warrant referral for dyslexia diagnosis in Grades 1-2; the LI group of children whose literacy outcomes did, but who were referred for diagnostic assessment after Grade 3. At the time of diagnosis, the percentage of poor performers on word-level literacy measures generally did not differ between the groups. Only the LE group contained fewer poor performers than the early-diagnosed and LI group on some word-reading measures. All groups showed similar distributions of phonological difficulties. There were no indications of compensation through vocabulary, memory or IQ in either late-diagnosed group. Our diagnosis-based study confirms and extends previous research-based studies on LE dyslexia. Moreover, it shows that LI dyslexia exists, which can be regarded as the existence of instructional casualties. The findings speak to issues of identification, diagnosis and compensation and call for further efforts to improve the early identification of dyslexia.

The relation of visual attention span with serial and discrete rapid automatized naming and reading.

Visual attention span (VAS) has been shown to make a unique contribution to reading skills over and above phonological awareness and rapid automatized naming (RAN). In the current study, we examined the nature of this unique relationship. In particular, we tested whether VAS reflects the retrieval of a verbal code, serial processing, or parallel multi-element processing. To this end, we presented 180 third graders with tasks for VAS, discrete RAN, and serial RAN as well as serial and discrete reading of short words, pseudowords, and long words. VAS was found to correlate with serial RAN but not with discrete RAN. More important, similar relations were found for VAS with serial and discrete reading, which clearly differed from the format-specific relations between RAN and reading. Together, these findings suggest that VAS and serial RAN are related but are associated with reading for different reasons. Serial RAN appears to reflect serial interword reading processes, whereas the unique contribution of VAS mainly involves the parallel processing of orthographic units within words.

Reading and Spelling Development Across Languages Varying in Orthographic Consistency: Do Their Paths Cross?

We examined the cross-lagged relations between reading and spelling in five alphabetic orthographies varying in consistency (English, French, Dutch, German, and Greek). Nine hundred and forty-one children were followed from Grade 1 to Grade 2 and were tested on word and pseudoword reading fluency and on spelling to dictation. Results indicated that the relations across languages were unidirectional: Earlier reading predicted subsequent spelling. However, we also found significant differences between languages in the strength of the effects of earlier reading on subsequent spelling. These findings suggest that, once children master decoding, the observed differences between languages are not related to the direction of the effects but to the strength of the effects from reading to spelling. Theoretical and practical implications are discussed.

Early and late diagnosed dyslexia in secondary school: Performance on literacy skills and cognitive correlates.

Although a diagnosis of dyslexia is often made during elementary school, severe and persistent literacy difficulties of a considerable group of students are only noticed during secondary school. The question arises whether the literacy(-related) deficits of these late identified students with dyslexia differ from those of early diagnosed students. To address this question, 10th Grade Dutch secondary school students with early (n = 35) and late (n = 19) identified dyslexia and their peers with average to good literacy abilities (n = 24) were compared on literacy skills and underlying cognitive skills. At the group level, both students with an early and late diagnosis performed more poorly than their typical peers, but they did not differ from each other on (pseudo-)word reading, spelling and underlying cognitive correlates (phonemic awareness, rapid automatized naming and visual attention span). The early and late group contained comparable percentages of students performing poorly on most measures. There were, however, more students in the early group who showed deficits in phonemic awareness. Our results indicate that students with early and late diagnosed dyslexia are highly comparable. Suggestions for fitting interventions are discussed.

Pathways Into Literacy: The Role of Early Oral Language Abilities and Family Risk for Dyslexia.

The present study investigated the role of early oral language and family risk for dyslexia in the two developmental pathways toward reading comprehension, through word reading and through oral language abilities. The sample contained 237 children (164 at family risk for dyslexia) from the Dutch Dyslexia Program. Longitudinal data were obtained on seven occasions when children were between 4 and 12 years old. The relationship between early oral language ability and reading comprehension at the age of 12 years was mediated by preliteracy skills and word-decoding ability for the first pathway and by later language abilities for the second pathway. Family risk influenced literacy development through its subsequent relations with preliteracy skills, word decoding, and reading comprehension. Although performance on language measures was often lower for the family-risk group than for the no-family-risk group, family risk did not have a specific relation with either early or later oral language abilities.

Development of verbal short-term memory and working memory in children with epilepsy: Developmental delay and impact of time-related variables. A cross-sectional study.

While short-term memory (STM) and working memory (WM) are understood as being crucial for learning, and children with epilepsy often experience learning difficulties, little is known about the age-related development of memory span tasks in children with epilepsy. Short-term memory and WM, operationalized as digit span forwards (DSF) or digit span backwards (DSB), respectively, were studied. Participants were 314 children with epilepsy and 327 typically developing children in ages between 5 and 15years and full scale intelligence quotient (FS-IQ)≥75. Cross-sectional analyses of the data were done with analyses of variance and analyses of covariance ((M)ANCOVAs) and generalized linear analyses. The analyses revealed that STM problems in epilepsy were mediated by age-related gains in WM as well as by differences in IQ. Working memory developed at a quick pace in the younger children, the pace slowed down to some extent in the later primary school years and resumed again later on. Working memory problems prevailed in epilepsy, independent of IQ and development of STM. Timing of the epilepsy in terms of age at onset and duration determined memory development. The youngest children with epilepsy showed age-appropriate development in STM but were the most vulnerable in terms of WM development. Later in the course of the epilepsy, the WM problems of the young children attenuated. In later onset epilepsy, WM problems were smaller but persisted over time.

Naming of short words is (almost) the same as naming of alphanumeric symbols: Evidence from two orthographies.

Throughout reading development, a gradual shift is seen in the processes underlying word identification from serial decoding toward parallel processing or sight word reading. It has been argued that this shift can be detected in the correlations between serial and discrete naming of alphanumeric symbols (digits and letters) and words. In the current study, we examined the relations between alphanumeric symbol naming and reading of monosyllabic and multisyllabic words and nonwords in two languages that differ in orthographic consistency: English and Dutch. A sample of 92 English-speaking Canadian children and 101 Dutch children, all in Grade 5, were assessed on discrete and serial naming of digits and letters and on serial and discrete naming of monosyllabic and multisyllabic words and nonwords. Results showed that discrete naming of alphanumeric symbols closely resembled discrete reading of monosyllabic words, suggesting that these words are processed in parallel in both languages. Both serial and parallel reading processes were found to underlie identification of multisyllabic words as well as monosyllabic nonwords. However, differences between the two languages emerged when processing multisyllabic nonwords. Whereas English-speaking children relied more on parallel reading processes to read multisyllabic nonwords, Dutch-speaking children processed these items serially. Theoretical implications of these findings are discussed.

Pediatric epilepsy and comorbid reading disorders, math disorders, or autism spectrum disorders: Impact of epilepsy on cognitive patterns.

INTRODUCTION: In pediatric epilepsy, comorbidities are reported to be frequent. The present study focusedon the cognitive patterns of children with isolated epilepsy, children with isolated neurodevelopmental disorders (reading disorders, math disorders, autism spectrum disorders), and children with epilepsy and these neurodevelopmental disorders as comorbidities. METHODS: Based on two samples of referred children, one with epilepsy, reading disorders, math disorders, or ASDs occurring in "isolation" (n=117) and one with reading disorders, math disorders, and ASDs occurring comorbid with epilepsy (n=171), cognitive patterns were compared. The patterns displayed by verbal and nonverbal abilities from the WISC series were studied with repeated measures ANOVA. Thereafter, an exploratory 2∗3∗2 factorial analysis was done to study the independent contribution of the type of comorbidity and of the presence or absence of epilepsy to the VIQ-PIQ pattern. RESULTS: In isolated epilepsy, a VIQ>PIQ pattern was found, which was not seen in the other disorders. When epilepsy and another disorder co-occurred, patterns were altered. They resembled partly the pattern seen in isolated epilepsy and partly the pattern seen in the isolated neurodevelopmental disorder. In comorbid reading disorders, the VIQ>PIQ pattern was mitigated; in comorbid math disorders, it was exacerbated. In comorbid ASDs, no clear pattern emerged. In the presence of epilepsy, patterns characteristic of isolated disorders appeared systematically shifted toward relatively lowered performance abilities or relatively spared verbal abilities. The similar "impact" exerted by epilepsy on the patterns of the various conditions suggested shared mechanisms.

Density and length in the neighborhood: Explaining cross-linguistic differences in learning to read in English and Dutch.

Two experiments examined underlying cognitive processes that may explain why it is harder to learn to read in English than in more transparent orthographies such as German and Dutch. Participants were English and Dutch readers from Grades 3 and 4. Experiment 1 probed the transition from serial to more parallel processing, as measured by the word length effect for words and pseudowords. English children took longer to make the transition to more parallel reading strategies for words than Dutch children. In contrast, Dutch children continued to use more serial reading strategies for pseudowords. Experiment 2 investigated children's sensitivity to the orthographic overlap between words, as measured by the size of orthographic neighborhood effects for words and pseudowords. Children reading Dutch showed greater sensitivity to the overlap between both words and pseudowords than English children. Cross-linguistic differences in the transition from serial to parallel reading strategies are discussed within the framework offered by the self-teaching hypothesis and the orthographic depth hypothesis. Finally, it is argued that differences between the two languages in the effect of orthographic neighborhood size are a result of cross-linguistic differences in orthographic density and not cross-linguistic differences in orthographic transparency.

Underlying skills of oral and silent reading.

Many studies have examined reading and reading development. The majority of these studies, however, focused on oral reading rather than on the more dominant silent reading mode. Similarly, it is common practice to assess oral reading abilities rather than silent reading abilities in schools and in diagnosis of reading impairments. More important, insights gained through examinations of oral reading tend to be generalized to silent reading. In the current study, we examined whether such generalizations are justified. We directly compared oral and silent reading fluency by examining whether these reading modes relate to the same underlying skills. In total, 132 fourth graders read words, sentences, and text orally, and 123 classmates read the same material silently. As underlying skills, we considered phonological awareness, rapid naming, and visual attention span. All skills correlated significantly with both reading modes. Phonological awareness contributed equally to oral and silent reading. Rapid naming, however, correlated more strongly with oral reading than with silent reading. Visual attention span correlated equally strongly with both reading modes but showed a significant unique contribution only to silent reading. In short, we showed that oral and silent reading indeed are fairly similar reading modes, based on the relations with reading-related cognitive skills. However, we also found differences that warrant caution in generalizing findings across reading modes.

The relational side of teachers' self-efficacy: Assimilation and contrast effects of classroom relational climate on teachers' self-efficacy.

Although much is known about the sources of teachers' self-efficacy (TSE), less attention has been paid to the social-contextual specificity of TSE and the processes influencing the relevance of TSE information sources. This study investigated both dyad-level relationships and the classroom relational climate as predictors of TSE at the student and classroom level. Additionally, we explored two competing hypotheses-assimilation and contrast-articulating how teachers use information conveyed by classroom relationship experiences as a heuristic to interpret relationship experiences with individual students as a TSE source. Elementary school teachers (N = 86; 72.05% female) completed the Student-Teacher Relationship Scale and Student-Specific Teacher Self-Efficacy Scale for randomly selected children (N = 687, 50.1% girls, Grades 3-6) from their classes. Doubly latent multilevel structural equation modeling was used to test for associations of Closeness and Conflict with TSE at both the student (L1) and classroom level (L2). Contextual effects, corresponding to associations of classroom-level Closeness and Conflict with TSE above the same associations at the student level, were calculated to test assimilation and contrast hypotheses. At L1, results indicated positive associations between Closeness and TSE and negative associations between Conflict and TSE. At L2, only Conflict was negatively associated with TSE. Consistent with the contrast hypothesis, the contextual effect of Closeness, but not Conflict, was negative and significant. Hence, teachers' judgments of a relatively close classroom relational climate may lead them to perceive relational closeness with individual students in a more negative light, resulting in lower levels of TSE toward these students.

Dissociating crossmodal and verbal demands in paired associate learning (PAL): what drives the PAL-reading relationship?

Recent research suggests that visual-verbal paired associate learning (PAL) may tap a crossmodal associative learning mechanism that plays a distinct role in reading development. However, evidence from children with dyslexia indicates that deficits in visual-verbal PAL are strongly linked to the verbal demands of the task. The primary aim of this study was to disassociate the role of modality and verbal demand in driving the PAL-reading relationship. To do so, we compared performance across four PAL mapping conditions: visual-verbal, verbal-verbal, visual-visual and verbal-visual. We reasoned that if crossmodal mapping demand accounts for the PAL-reading relationship, both visual-verbal PAL and verbal-visual PAL should exhibit significant relationships with reading ability. The results were incompatible with the crossmodal hypothesis. Only tasks requiring verbal output (visual-verbal PAL and verbal-verbal PAL) significantly correlated with reading ability. In addition, visual-verbal PAL and verbal-verbal PAL were well represented by a latent "verbal output PAL" factor. Structural equation modeling showed that this factor fully accounted for the PAL-reading relationship; visual-verbal PAL did not add anything to the prediction of reading above and beyond this latent factor. The results are interpreted according to an alternative verbal account of the PAL-reading relationship.

Perceived negative consequences of dyslexia: the influence of person and environmental factors.

Perceived negative consequences of dyslexia entail the degree to which an individual perceives negative outcomes, such as low academic achievement or feelings of anxiety and depression, and attributes these experiences to the disorder. In the current study, we examined how perceived consequences of dyslexia are influenced by person and environmental factors. Perceived consequences were evaluated for the academic domain and the domain of mental health (depression, anxiety). Participants were 123 Dutch students with dyslexia. Cognitive person factors (literacy skills and verbal IQ), socio-emotional person factors (self-perceived literacy skills and coping ability), and environmental factors (literacy demands, support from the institution, reactions of teachers and peers) were included as predictors. Results indicated that perceived negative consequences were not related to cognitive person factors. In contrast, better self-perceived literacy skills were associated with less perceived negative consequences in all domains (academic, depression, anxiety) and coping contributed to depression consequences. With respect to environmental factors, negative reactions in the academic environment contributed to perceived negative consequences of depression and anxiety. As such, findings indicate that individuals with dyslexia perceive negative consequences in the academic, anxiety, and depression domains which cannot be fully accounted for by their objective reading and writing problems. These factors should feature more prominently in future studies on dyslexia and should be addressed in treatment of dyslexia as well.

Child and parental literacy levels within families with a history of dyslexia.

BACKGROUND: The present study concerns literacy and its underlying cognitive skills in Dutch children who differ in familial risk (FR) for dyslexia. Previous studies with FR-children were inconclusive regarding the performance of FR-children without dyslexia as compared to the controls. Moreover, van Bergen et al. (2011) recently showed that FR-children with and without dyslexia differed in parental reading skills, suggesting that those who go on to develop dyslexia have a higher liability. The current study concerned 1) the comparison of three groups of children at the end of second grade and 2) the intergenerational transfer of reading and its underlying cognitive skills from parent to child. METHOD: Three groups of children were studied at the end of second grade: FR-dyslexia (n = 42), FR-no-dyslexia (n = 99), and control children (n = 66). Parents and children were measured on naming, phonology, spelling, and word and pseudoword reading. RESULTS: The FR-dyslexia children were severely impaired across all tasks. The FR-no-dyslexia children performed better than the FR-dyslexia children, but still below the level of the controls on all tasks; the only exception was rapid naming (RAN), on which they were as fast as the controls. Focusing on the FR subsample, parental reading and RAN were related to their offspring's reading status. CONCLUSIONS: We replicated and extended van Bergen et al.'s study in showing that the FR-children who develop dyslexia are likely to have a higher liability. Both the group comparisons and the parent-child relations highlight the importance of good RAN skills for reading acquisition.

Parent-child conflict during homeschooling in times of the COVID-19 pandemic: A key role for mothers' self-efficacy in teaching.

To contain the COVID-19 pandemic schools have been closed in many countries. Children stayed at home and were assisted by their parents with their schoolwork. Evidently, homeschooling puts extra demands on parents. We presumed that parents' sense of efficacy in teaching would play a key role in how they cope with this extra task of homeschooling. In particular, we hypothesized that parental characteristics (level of parental education and stress) and social contextual factors (household chaos and school support) would contribute to parents' teaching self-efficacy and that, in turn, a lower efficacy would result in more parent-child conflict during home schooling. Participants were 173 mothers of children in kindergarten or early elementary schools, who provided information for one of their children about interpersonal conflicts around schoolwork before and during school closure. Additionally, they reported on their self-efficacy in teaching, perceived stress during lockdown, home chaos, and school support. Path analyses indicated that mothers' perceived stress and household chaos were associated with a lower sense of efficacy in teaching, whereas school support, but not level of parental education, was related to a higher level of teaching self-efficacy. Higher levels of self-efficacy beliefs, in turn, were associated with a lower degree of mother-child conflict during schoolwork, even after controlling for prior levels of conflict. We discuss how the results of this study might be used to foster parents' self-efficacy in teaching and thereby decrease the amount of parent-child conflict during parents' support with schoolwork.

Lexicality effects on orthographic learning in beginning and advanced readers of Dutch: An eye-tracking study.

Orthographic learning is the topic of many recent studies about reading, but much is still unknown about conditions that affect orthographic learning and their influence on reading fluency development over time. This study investigated lexicality effects on orthographic learning in beginning and relatively advanced readers of Dutch. Eye movements of 131 children in Grades 2 and 5 were monitored during an orthographic learning task. Children read sentences containing pseudowords or low-frequency real words that varied in number of exposures. We examined both offline learning outcomes (i.e., orthographic choice and spelling dictation) of target items and online gaze durations on target words. The results showed general effects of exposure, lexicality, and reading-skill level. Also, a two-way interaction was found between the number of exposures and lexicality when detailed orthographic representations were required, consistent with a larger overall effect of exposure on learning the spellings of pseudowords. Moreover, lexicality and reading-skill level were found to affect the learning rate across exposures based on a decrease in gaze durations, indicating a larger learning effect for pseudowords in Grade 5 children. Yet, further interactions between exposure and reading-skill level were not present, indicating largely similar learning curves for beginning and advanced readers. We concluded that the reading system of more advanced readers may cope somewhat better with words varying in lexicality, but is not more efficient than that of beginning readers in building up orthographic knowledge of specific words across repeated exposures.

Orthographic context and the acquisition of orthographic knowledge in normal and dyslexic readers.

We tested the hypothesis that the acquisition of orthographic knowledge of novel words that are presented in an indistinct context, that is a context with many orthographically similar words, would be more difficult for dyslexic than for normal readers. Participants were 19 Dutch dyslexic children (mean age 10;9 years), 20 age-matched and 20 reading-age-matched normal readers. During training the children repeatedly read a series of nonwords in a distinct (KWOG with KWES and SNAR) and an indistinct (KWOG with KWOS and KROG) orthographic context. At posttest, the dyslexic children were slower but more accurate in the reading of nonwords if these had been acquired in an indistinct than in a distinct training context. In normal readers context did not have an effect. We argue that dyslexic children's sensitivity to orthographic context is due to their problems in the acquisition of fully specified orthographic representations causing interference by similar words.

Dutch children at family risk of dyslexia: precursors, reading development, and parental effects.

The study concerns reading development and its precursors in a transparent orthography. Dutch children differing in family risk for dyslexia were followed from kindergarten through fifth grade. In fifth grade, at-risk dyslexic (n = 22), at-risk non-dyslexic (n = 45), and control children (n = 12) were distinguished. In kindergarten, the at-risk non-dyslexics performed better than the at-risk dyslexics, but worse than the controls on letter-knowledge and rapid naming. The groups did not differ on phonological awareness. At-risk dyslexics read less fluently from first grade onwards than the other groups. At-risk non-dyslexics' reading fluency was at an intermediate position between the other groups at the start of reading. By fifth grade they had reached a similar level as the controls on word reading, but still lagged behind on pseudoword reading. Results further showed that the parents of the groups of at-risk children differed in educational level and reading skills. Overall, the groups of at-risk children differed on pre-reading skills as well as on reading development. These differences do not seem to stem from differences in intellectual abilities or literacy environment. Instead, the better reading skills of parents of at-risk non-dyslexics suggest that these children might have a lower genetic liability.