Functional connectivity is linked to working memory differences in children with reading learning disability.

Reading learning disability (RLD) is characterized by a specific difficulty in learning to read that is not better explained by an intellectual disability, lack of instruction, psychosocial adversity, or a neurological disorder. According to the domain-general hypothesis, a working memory deficit is the primary problem. Working memory in this population has recently been linked to altered resting-state functional connectivity within the default mode network (DMN), salience network (SN), and frontoparietal network (FPN) compared to that in typically developing individuals. The main purpose of the present study was to compare the within-network functional connectivity of the DMN, SN, FPN, and reading network in two groups of children with RLD: a group with lower-than-average working memory (LWM) and a group with average working memory (AWM). All subjects underwent resting-state functional magnetic resonance imaging (fMRI), and data were analyzed from a network perspective using the network brain statistics framework. The results showed that the LWM group had significantly weaker connectivity in a network that involved brain regions in the DMN, SN, and FPN than the AWM group. Although there was no significant difference between groups in reading network in the present study, other studies have shown relationship of the connectivity of the angular gyrus, supramarginal gyrus, and inferior parietal lobe with the phonological process of reading. The results suggest that although there are significant differences in functional connectivity in the associated networks between children with LWM and AWM, the distinctive cognitive profile has no specific effect on the reading network.

Rapid online assessment of reading and phonological awareness (ROAR-PA).

Phonological awareness (PA) is at the foundation of reading development: PA is introduced before formal reading instruction, predicts reading development, is a target for early intervention, and is a core mechanism in dyslexia. Conventional approaches to assessing PA are time-consuming and resource intensive: assessments are individually administered and scoring verbal responses is challenging and subjective. Therefore, we introduce a rapid, automated, online measure of PA-The Rapid Online Assessment of Reading-Phonological Awareness-that can be implemented at scale without a test administrator. We explored whether this gamified, online task is an accurate and reliable measure of PA and predicts reading development. We found high correlations with standardized measures of PA (CTOPP-2, r = .80) for children from Pre-K through fourth grade and exceptional reliability (α = .96). Validation in 50 first and second grade classrooms showed reliable implementation in a public school setting with predictive value of future reading development.

Mediators of working memory and reading in a sample of children with reading difficulty: The roles of phonemic awareness and rapid automatized naming.

Working memory (WM) has been consistently linked to reading. However, the mechanism(s) linking WM to reading remain unclear. WM may indirectly exert an effect onto reading through mediators such as phonemic awareness (PA) and/or rapid automatized naming (RAN). In a sample of children with reading difficulty (n = 117), separate mediation analyses tested direct and indirect (through PA and RAN) effects of WM on untimed word decoding and recognition (i.e., basic reading skills) and timed word decoding and recognition (i.e., reading fluency). WM exerted a direct effect on basic reading skills and reading fluency. For basic reading skills, there was a significant indirect effect of WM on reading through the mediation of PA (but not through RAN). By contrast, for reading fluency, there was a significant indirect effect of WM on reading through the mediation of RAN (but not through PA). Findings reinforce the importance of WM, PA, and RAN for broad reading skills, while offering a mechanistic explanation for why poor PA and/or RAN may differentially lead to reading difficulty.

Human-specific insights into candidate genes and boosted discoveries of novel loci illuminate roles of neuroglia in reading disorders.

Reading disorders (RD) are human-specific neuropsychological conditions associated with decoding printed words and/or reading comprehension. So far only a handful of candidate genes segregated in families and 42 loci from genome-wide association study (GWAS) have been identified that jointly provided little clues of pathophysiology. Leveraging human-specific genomic information, we critically assessed the RD candidates for the first time and found substantial human-specific features within. The GWAS candidates (i.e., population signals) were distinct from the familial counterparts and were more likely pleiotropic in neuropsychiatric traits and to harbor human-specific regulatory elements (HSREs). Candidate genes associated with human cortical morphology indeed showed human-specific expression in adult brain cortices, particularly in neuroglia likely regulated by HSREs. Expression levels of candidate genes across human brain developmental stages showed a clear pattern of uplifted expression in early brain development crucial to RD development. Following the new insights and loci pleiotropic in cognitive traits, we identified four novel genes from the GWAS sub-significant associations (i.e., FOXO3, MAPT, KMT2E and HTT) and the Semaphorin gene family with functional priors (i.e., SEMA3A, SEMA3E and SEMA5B). These novel genes were related to neuronal plasticity and disorders, mostly conserved the pattern of uplifted expression in early brain development and had evident expression in cortical neuroglial cells. Our findings jointly illuminated the association of RD with neuroglia regulation-an emerging hotspot in studying neurodevelopmental disorders, and highlighted the need of improving RD phenotyping to avoid jeopardizing future genetic studies of RD.

POU6F2, a risk factor for glaucoma, myopia and dyslexia, labels specific populations of retinal ganglion cells.

Pou6f2 is a genetic connection between central corneal thickness (CCT) in the mouse and a risk factor for developing primary open-angle glaucoma. POU6F2 is also a risk factor for several conditions in humans, including glaucoma, myopia, and dyslexia. Recent findings demonstrate that POU6F2-positive retinal ganglion cells (RGCs) comprise a number of RGC subtypes in the mouse, some of which also co-stain for Cdh6 and Hoxd10. These POU6F2-positive RGCs appear to be novel of ON-OFF directionally selective ganglion cells (ooDSGCs) that do not co-stain with CART or SATB2 (typical ooDSGCs markers). These POU6F2-positive cells are sensitive to damage caused by elevated intraocular pressure. In the DBA/2J mouse glaucoma model, heavily-labeled POU6F2 RGCs decrease by 73% at 8 months of age compared to only 22% loss of total RGCs (labeled with RBPMS). Additionally, Pou6f2-/- mice suffer a significant loss of acuity and spatial contrast sensitivity along with an 11.4% loss of total RGCs. In the rhesus macaque retina, POU6F2 labels the large parasol ganglion cells that form the magnocellular (M) pathway. The association of POU6F2 with the M-pathway may reveal in part its role in human glaucoma, myopia, and dyslexia.

Handwriting difficulties in children with dyslexia: Poorer legibility in dictation and alphabet tasks, slowness in the alphabet task.

Several studies have shown that children with dyslexia (DYS), in addition to their reading and spelling deficits, encounter handwriting difficulties that are still poorly understood in terms of their nature and origin. The present study aimed to better understand the handwriting difficulties of children with DYS by comparing their handwriting quality and speed in two tasks, a dictation task and an alphabet task, which required fewer spelling skills than the dictation task. Twenty-nine French-speaking children (Mage = 9.5 years) participated in the study, including 18 children with DYS and nine typically developing (TD) children matched on chronological age. The children performed control tasks, a dictation task with words varying in graphic and orthographic complexity and an alphabet writing task. Accuracy, handwriting quality (legibility), and fluency (speed, writing and pause time) were carefully measured using a digital tablet. GLMM analysis and t tests showed that children with DYS made more aesthetic errors (handwriting quality) in both the dictation and alphabet task than TD children. They also wrote more slowly than TD children in the alphabet task (speed, pause time). These findings suggest that children with DYS present handwriting difficulties, even in a simple alphabet task. In dictation, they seem to favour speed at the expense of handwriting quality.

Investigating low intelligence stereotype threat in adults with developmental dyslexia.

Stereotype threat (ST) is a phenomenon that leads to decreased test performance and occurs when one deals with added pressure of being judged on the basis of stereotyped group membership. The ST effect has been previously investigated in many contexts but not in individuals with dyslexia who are often stereotyped as less intelligent. Prevalent use of intelligence tests in job selection processes and employment gap between people with dyslexia and those without warrants this investigation. Sixty-three participants (30 with dyslexia and 33 without dyslexia; mean age = 33.7; SD = 13.7; 47 F, 13 M, three non-binary) were asked to complete intelligence test typically used in selection processes. All participants were randomly assigned to one of three test instruction conditions: (1) they were told the test was diagnostic of their intelligence (ST triggering instruction); (2) test was a measure of their problem-solving skills (reduced threat); (3) or they were simply asked to take the test (control). Results showed that participants with dyslexia in ST condition performed poorer than those in other conditions and those in the same condition who did not have dyslexia. This study provides preliminary evidence for diminishing effects of ST in individuals with dyslexia.

Motor skills and capacities in developmental dyslexia: A systematic review and meta-analysis.

In recent decades, the connections between academic skills, such as reading, writing, and calculation, and motor skills/capacities have received increasing attention. Many studies provided evidence for motor difficulties in children and adolescents with dyslexia, prompting the need for a meta-analysis to combine these multiple findings. Therefore, we conducted a meta-analysis using PsycINFO, Pubmed, and SportDiscus as scientific databases. A total of 572 studies were analyzed following several stringent inclusion criteria, resulting in the inclusion of 23 peer-reviewed studies in the final analysis. Our results showed that children and adolescents with dyslexia displayed significant different performances in multiple motor tasks and these differences persisted also when the type of motor task was considered as moderator in the analysis. The present findings are in accordance with the literature that supports a close connection between reading disabilities and difficulties in motor skills/capacities.

A systematic review of factors that impact reading comprehension in children with developmental language disorders.

Children with developmental language disorder (DLD) have a high rate of co-occurring reading difficulties. The current study aims to (i) examine which factors within the Active View of Reading (AVR; Duke & Cartwright, 2021) apply to individuals with DLD and (ii) investigate other possible factors that relate to reading comprehension ability in individuals with DLD, outside the components in the AVR. Electronic database search and journal hand-search yielded 5058 studies published before March 2022 related to reading comprehension in children with DLD. 4802 articles were excluded during abstract screening, yielding 256 studies eligible for full-text review. Following full-text review, 44 studies were included and further coded for demographics, language of assessment, description of reported disabilities, behavioral assessment, and reading comprehension assessment. While the results aligned with the AVR model, three additional factors were identified as significantly relating to reading comprehension abilities in children with DLD: expressive language (oral and written), question types of reading assessment, and language disorder history. Specifically, expressive language was positively associated with reading comprehension ability, while resolved DLD showed higher reading comprehension abilities than persistent DLD. Furthermore, children with DLD may face additional difficulties in comprehending inference-based questions. This study provides factors for researchers, educators, and clinical professionals to consider when evaluating the reading comprehension of individuals with DLD. Future research should further explore the relative importance of factors of the AVR to reading comprehension outcomes throughout development.

An executive-functions-based reading training enhances sensory-motor systems integration during reading fluency in children with dyslexia.

The Simple View of Reading model suggests that intact language processing and word decoding lead to proficient reading comprehension, with recent studies pointing at executive functions as an important component contributing to reading proficiency. Here, we aimed to determine the underlying mechanism(s) for these changes. Participants include 120 8- to 12-year-old children (n = 55 with dyslexia, n = 65 typical readers) trained on an executive functions-based reading program, including pre/postfunctional MRI and behavioral data collection. Across groups, improved word reading was related to stronger functional connections within executive functions and sensory networks. In children with dyslexia, faster and more accurate word reading was related to stronger functional connections within and between sensory networks. These results suggest greater synchronization of brain systems after the intervention, consistent with the "neural noise" hypothesis in children with dyslexia and support the consideration of including executive functions as part of the Simple View of Reading model.

Association between urinary BTEX metabolites and dyslexic odds among school-aged children.

Benzene, toluene, ethylbenzene, and xylene (BTEX) are ubiquitous in the environment, and all of them can cause neurotoxicity. However, the association between BTEX exposure and dyslexia, a disorder with language network-related regions in left hemisphere affected, remains unclear. We aimed to assess the relationship between BTEX exposure and dyslexic odds among school-aged children. A case-control study, including 355 dyslexics and 390 controls from three cities in China, was conducted. Six BTEX metabolites were measured in their urine samples. Logistic regression model was used to explore the association between the BTEX metabolites and the dyslexic odds. Urinary trans,trans-muconic acid (MU: a metabolite of benzene) was significantly associated with an increased dyslexic odds [odds ratio (OR) = 1.23, 95% confidence interval (CI): 1.01, 1.50], and the adjusted OR of the dyslexic odds in the third tertile was 1.72 (95% CI: 1.06, 2.77) compared to that in the lowest tertile regarding urinary MU concentration. Furthermore, the association between urinary MU level and the dyslexic odds was more pronounced among children from low-income families based on stratified analyses. Urinary metabolite levels of toluene, ethylbenzene, and xylene were not found to be associated with the dyslexic odds. In summary, elevated MU concentrations may be associated with an increased dyslexic odds. We should take measures to reduce MU related exposure among children, particularly those with low family income.

The informant matters: Differences in bullying victim categorization rates assessed with self- and peer-reports in children with developmental language disorder and reading difficulties.

BACKGROUND: Children with Developmental Language Disorder (DLD) and Reading Difficulties (RD) can show more peer relation problems depending on the informant. AIMS: (1) To explore bullying victims' categorization, evaluated by self- and peer-reports, in children with DLD and RD; and (2) to assess agreement rates between informants. METHOD AND PROCEDURES: Victimization was assessed using a self-report (EBIP-Q) and a peer-report sociogram (CESC) in a sample of 83 participants (9-12 years; 10.5 ± 1.1 years), comprising of DLD (n = 19), RD (n = 32), and Control (n = 32) groups. OUTCOMES AND RESULTS: We found a higher frequency of the rejected sociometric profile in the DLD and RD groups, a higher peer-reported victimization in the DLD group, and more severe self-reported victimization in the DLD and RD groups. Odds of being classified as victimized were higher for self-report except in the DLD group. Informants' agreement was high using the most restrictive EBIP-Q criterion (7 points) for both the Control and the RD groups, being non-significant for the DLD group regardless of the criteria used. CONCLUSIONS AND IMPLICATIONS: We found a higher victimization risk in children with language difficulties, although self-assessment seems to under-detect children with DLD according to the agreement rates, pointing out the need to combine assessments and informants. WHAT DOES THIS PAPER ADD?: Several studies have shown that children with DLD or RD obtain higher scores of victimization and score lower on several scales of social skills with continuous data. Although continuous analyses are usual in research, professional decisions are usually based on cut-off criteria more than how high or low a score is in contrast to another group. This is one of the first works that analyses victimization following the cut-off criteria of self and peer assessments that professionals used in the school settings in children with DLD and RD. Our results will raise awareness among school professionals based on the evidence about the high risk of victimization, especially in children with DLD, and the implications of selecting between several measures of victimization, in this group of children. We think that our results would help to better detect and prevent bullying in schools for children with DLD.

Action video games and posterior parietal cortex neuromodulation enhance both attention and reading in adults with developmental dyslexia.

The impact of action video games on reading performance has been already demonstrated in individuals with and without neurodevelopmental disorders. The combination of action video games and posterior parietal cortex neuromodulation by a transcranial random noise stimulation could enhance brain plasticity, improving attentional control and reading skills also in adults with developmental dyslexia. In a double blind randomized controlled trial, 20 young adult nonaction video game players with developmental dyslexia were trained for 15 h with action video games. Half of the participants were stimulated with bilateral transcranial random noise stimulation on the posterior parietal cortex during the action video game training, whereas the others were in the placebo (i.e. sham) condition. Word text reading, pseudowords decoding, and temporal attention (attentional blink), as well as electroencephalographic activity during the attentional blink, were measured before and after the training. The action video game + transcranial random noise stimulation group showed temporal attention, word text reading, and pseudoword decoding enhancements and P300 amplitude brain potential changes. The enhancement in temporal attention performance was related with the efficiency in pseudoword decoding improvement. Our results demonstrate that the combination of action video game training with parietal neuromodulation increases the efficiency of visual attention deployment, probably reshaping goal-directed and stimulus-driven fronto-parietal attentional networks interplay in young adults with neurodevelopmental conditions.

Developmental dyslexia susceptibility genes DNAAF4, DCDC2, and NRSN1 are associated with brain function in fluently reading adolescents and young adults.

Reading skills and developmental dyslexia, characterized by difficulties in developing reading skills, have been associated with brain anomalies within the language network. Genetic factors contribute to developmental dyslexia risk, but the mechanisms by which these genes influence reading skills remain unclear. In this preregistered study (https://osf.io/7sehx), we explored if developmental dyslexia susceptibility genes DNAAF4, DCDC2, NRSN1, and KIAA0319 are associated with brain function in fluently reading adolescents and young adults. Functional MRI and task performance data were collected during tasks involving written and spoken sentence processing, and DNA sequence variants of developmental dyslexia susceptibility genes previously associated with brain structure anomalies were genotyped. The results revealed that variation in DNAAF4, DCDC2, and NRSN1 is associated with brain activity in key language regions: the left inferior frontal gyrus, middle temporal gyrus, and intraparietal sulcus. Furthermore, NRSN1 was associated with task performance, but KIAA0319 did not yield any significant associations. Our findings suggest that individuals with a genetic predisposition to developmental dyslexia may partly employ compensatory neural and behavioral mechanisms to maintain typical task performance. Our study highlights the relevance of these developmental dyslexia susceptibility genes in language-related brain function, even in individuals without developmental dyslexia, providing valuable insights into the genetic factors influencing language processing.

Evaluation of the multiple-deficit hypothesis among dyslexic Arabic-speaking children.

This study examined the multiple-deficit hypothesis among Arabic-speaking elementary school students. A total of 90 students, divided into three main groups based on their performance on an Arabic word-reading task: dyslexic (n = 30), regular age-matched (n = 30), and 3rd-grade regular students, who were matched to the dyslexic group in regard to their reading proficiency level (n = 30). Participants underwent a nine-domain Arabic reading experiment that measured accuracy and fluency to evaluate general reading proficiency. The performance of Arabic dyslexic students was significantly worse than age-matched controls, but similar to young matched controls based on the reading level of each cognitive task. Moreover, dyslexic students showed deficits in three or more cognitive functions, depending on severity. This study adds to the limited empirical research on the double-deficit hypothesis and its extension to the multiple-domain model among young Arabic students.

Computerized Executive Functions Training: The efficacy on reading performance of children with dyslexia.

This study aimed to test the efficacy of a newly developed computer-based game naming computerized executive functions (CEF) task on the reading ability of children suffering from dyslexia. Forty dyslexic school students from the fourth and fifth grades were randomized to one of the experimental and control groups. Subjects of the experimental group received 12 sessions of Computerized Executive Functions Training (CEFT), while subjects of the control group played a neutral computer game throughout the 12 sessions. All participants responded to the Reading and Dyslexia Test (NEMA) as the pre- and post-test measure. Results revealed a significant improvement in the reading ability of subjects of the experimental group compared to the control group. Subjects of the experimental group indicated a greater improvement in some components of the NEMA scale including word reading, word chains reading, picture naming, text comprehension, word comprehension and letter fluency relative to the control group. CEFT had no significant effect in modifying the category fluency, phoneme elimination and rhyming components of the NEMA scale. Applying CEFT improves the reading performance of children with dyslexia by enforcing their cognitive abilities like working memory, inhibition control and cognitive flexibility which are necessary for normal reading ability.

Technical adequacy of measuring teachers' knowledge of dyslexia.

Given the rapid growth in educational policies targeting educators' knowledge of dyslexia, this study explored the technical adequacy of a common instrument for measuring that knowledge. The responses of 1141 preservice teachers were scored in three ways: polytomously with the original 4-point Likert scale, dichotomously as true-false, and dichotomously as though the options were multiple choice. An exploratory factor analysis suggested at least one-third of the items needed to be removed. Confirmatory factor analyses suggested a one-factor model with polytomous scoring had the best fit to the data, but only six items loaded. All models demonstrated unacceptable internal consistency reliability (<0.70). Because no technically adequate version of the measure was identified, questions remain about basing policy on scores from these instruments. However, the findings indicated ways this type of measure might be improved.

Prismatic adaptation coupled with cognitive training as novel treatment for developmental dyslexia: a randomized controlled trial.

Despite intense and costly treatments, developmental dyslexia (DD) often persists into adulthood. Several brain skills unrelated to speech sound processing (i.e., phonology), including the spatial distribution of visual attention, are abnormal in DD and may represent possible treatment targets. This study explores the efficacy in DD of rightward prismatic adaptation (rPA), a visuomotor adaptation technique that enables visuo-attentive recalibration through shifts in the visual field induced by prismatic goggles. A digital intervention of rPA plus cognitive training was delivered weekly over 10 weeks to adolescents with DD (aged 13-17) assigned either to treatment (N = 35) or waitlist (N = 35) group. Efficacy was evaluated by repeated measures MANOVA assessing changes in working memory index (WMI), processing speed index (PSI), text reading speed, and words/pseudowords reading accuracy. rPA treatment was significantly more effective than waitlist (p ≤ 0.001; ηp2 = 0.815). WMI, PSI, and reading speed increased in the intervention group only (p ≤ 0.001, ηp2 = 0.67; p ≤ 0.001, ηp2 = 0.58; p ≤ 0.001, ηp2 = 0.29, respectively). Although modest change was detected for words and pseudowords accuracy in the waitlist group only (words: p ≤ 0.001, d = 0.17, pseudowords: p = 0.028; d = 0.27), between-group differences were non-significant. rPA-coupled cognitive training enhances cognitive and reading abilities in adolescents with DD. This innovative approach could have implications for early remedial treatment.