What Factors Facilitate Resilience in Developmental Dyslexia? Examining Protective and Compensatory Mechanisms Across the Neurodevelopmental Trajectory

Longitudinal trajectories of brain development from infancy to school age and their relationship to literacy development

Reading is one of the most complex skills that we utilize daily, and it involves the early development and interaction of various lower-level subskills, including phonological processing and oral language. These subskills recruit brain structures, which begin to develop long before the skill manifests and exhibit rapid development during infancy. However, how longitudinal trajectories of early brain development in these structures support long-term acquisition of literacy subskills and subsequent reading is unclear. Children underwent structural and diffusion MRI scanning at multiple timepoints between infancy and second grade and were tested for literacy subskills in preschool and decoding and word reading in early elementary school. We developed and implemented a reproducible pipeline to generate longitudinal trajectories of early brain development to examine associations between these trajectories and literacy (sub)skills. Furthermore, we examined whether familial risk of reading difficulty and children's home literacy environments, two common literacy-related covariates, influenced those trajectories. Results showed that individual differences in curve features (e.g., intercepts and slopes) for longitudinal trajectories of volumetric, surface-based, and white matter organization measures were linked directly to phonological processing and indirectly to first-grade decoding and word reading skills via phonological processing. Altogether, these findings suggest that the brain bases of phonological processing, previously identified as the strongest behavioral predictor of reading and decoding skills, may already begin to develop by birth but undergo further refinement between infancy and preschool. The present study underscores the importance of considering academic skill acquisition from the very beginning of life.

The role of formal schooling in the development of children's reading and arithmetic white matter networks

Children's white matter development is driven by experience, yet it remains poorly understood how it is shaped by attending formal education. A small number of studies compared children before and after the start of formal schooling to understand this, yet they do not allow to separate maturational effects from schooling-related effects. A clever way to (quasi-)experimentally address this issue is the longitudinal school cut-off design, which compares children who are similar in age but differ in schooling (because they are born right before or after the cut-off date for school entry). We used for the first time such a longitudinal school cut-off design to experimentally investigate the effect of schooling on children's white matter networks. We compared "young" first graders (schooling group, n = 34; Mage = 68 months; 20 girls) and "old" preschoolers (non-schooling group, n = 33; Mage = 66 months; 18 girls) that were similar in age but differed in the amount of formal instruction they received. Our study revealed that changes in fractional anisotropy and mean diffusivity in five a priori selected white matter tracts during the transition from preschool to primary school were predominantly driven by age-related maturation. We did not find specific schooling effects on white matter, despite their strong presence for early reading and early arithmetic skills. The present study is the first to disentangle the effects of age-related maturation and schooling on white matter within a longitudinal cohort of 5-year-old preschoolers. RESEARCH HIGHLIGHTS: White matter tracts that have been associated with reading and arithmetic may be susceptible to experience-dependent neuroplasticity when children learn to read and calculate. This longitudinal study used the school cut-off design to isolate schooling-induced from coinciding maturational influences on children's white matter development. White matter changes during the transition from preschool to primary school are predominantly driven by age-related maturation and not by schooling effects. Strong effects of schooling on behavior were shown for early reading and early arithmetic, but not for verbal ability and spatial ability.

Cortical Structure in Pre-Readers at Cognitive Risk for Dyslexia: Baseline Differences and Response to Intervention

Early childhood is a critical period for structural brain development as well as an important window for the identification and remediation of reading difficulties. Recent research supports the implementation of interventions in at-risk populations as early as kindergarten or first grade, yet the neurocognitive mechanisms following such interventions remain understudied. To address this, we investigated cortical structure by means of anatomical MRI before and after a 12-week tablet-based intervention in: (1) at-risk children receiving phonics-based training (n = 29; n = 16 complete pre-post datasets), (2) at-risk children engaging with AC training (n = 24; n = 15 complete pre-post datasets) and (3) typically developing children (n = 25; n = 14 complete pre-post datasets) receiving no intervention. At baseline, we found higher surface area of the right supramarginal gyrus in at-risk children compared to typically developing peers, extending previous evidence that early anatomical differences exist in children who may later develop dyslexia. Our longitudinal analysis revealed significant post-intervention thickening of the left supramarginal gyrus, present exclusively in the intervention group but not the active control or typical control groups. Altogether, this study contributes new knowledge to our understanding of the brain morphology associated with cognitive risk for dyslexia and response to early intervention, which in turn raises new questions on how early anatomy and plasticity may shape the trajectories of long-term literacy development.

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.

Longitudinal Predictors of Word Reading for Children with Williams Syndrome

We examined the cognitive, language, and instructional predictors of early word-reading ability in a sample of children with Williams syndrome longitudinally. At Time 1, sixty-nine 6-7-year-olds (mean age = 6.53 years) completed standardized measures of phonological awareness, visual-spatial perception, vocabulary, and overall intellectual ability. Word-reading instruction type was classified as (systematic) Phonics (n = 35) or Other (n = 34). At Time 2, approximately three years later (mean age = 9.47 years), children completed a standardized assessment of single-word reading ability. Reading ability at Time 2 varied considerably, from inability to read any words to word-reading ability slightly above the level expected for age. The results of a multiple regression indicated that Time 1 word-reading instruction type, phonological awareness, and visual-spatial perception (as assessed by a matching letter-like forms measure) each explained significant unique variance in word reading at Time 2. A systematic phonics approach was associated with significantly better performance than other reading-instruction approaches. Exploratory analyses suggested that the relations between these factors were complex. Considered together, these findings strongly suggest that, in line with the Cumulative Risk and Resilience Model of reading disability, word-reading (dis)ability in Williams syndrome is probabilistic in nature, resulting from the interaction of multiple individual and environmental risk and protective factors. The results also have educational implications: Early word-reading instruction for children with Williams syndrome should combine systematic phonics and phonological awareness training while also incorporating letter discrimination instruction highlighting the visual-spatial differences between similar-appearing letters.

Preliteracy Skills Mediate the Relation Between Early Speech Sound Production and Subsequent Reading Outcomes

PURPOSE

Learning to read is a complex, multifaceted process that relies on several speech and language-related subskills. Individual differences in word reading outcomes are indicated among children with inaccurate speech sound productions, with some of these children developing later reading difficulties. There are inconsistent reports as to whether phonological deficits and/or weaknesses in oral language explain these subsequent reading difficulties. Thus, it remains unclear how variability in speech production accuracy in early childhood may impact reading development. Therefore, the present longitudinal study seeks to clarify the relation between speech sound production accuracy in kindergarten and subsequent reading outcomes with a focus on additional potential mediating factors.

METHOD

Speech accuracy, core preliteracy skills (phonological awareness, rapid naming, and letter-name knowledge), and additional potential mediators (phonological memory and oral language abilities) were characterized at the start of formal reading instruction. Word reading, decoding, reading fluency, and comprehension were assessed at the end of second grade. Mediation analyses were conducted to examine factors that mediate the relation between speech accuracy in kindergarten and subsequent reading outcomes.

RESULTS

Initial associations between early speech sound production accuracy and subsequent reading outcomes were indicated; however, mediation effects of preliteracy skills (phonological awareness and letter-name knowledge) were identified for word reading, decoding, and reading fluency outcomes. For reading comprehension, mediation effects of preliteracy and vocabulary skills were observed.

CONCLUSIONS

The relation between speech sound production accuracy and subsequent word reading, decoding, reading fluency, and comprehension was observed to be mediated by preliteracy skills, specifically phonological awareness and letter-name knowledge. For reading comprehension only, vocabulary knowledge were of additional importance.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.23671491.

Examining Shared Reading and White Matter Organization in Kindergarten in Relation to Subsequent Language and Reading Abilities: A Longitudinal Investigation

Parent-child language interaction in early childhood carries long-term implications for children's language and reading development. Conversational interaction, in particular, has been linked to white matter organization of neural pathways critical for language and reading. However, shared book reading serves an important role for language interaction as it exposes children to sophisticated vocabulary and syntax. Despite this, it remains unclear whether shared reading also relates to white matter characteristics subserving language and reading development. If so, to what extent do these environmentally associated changes in white matter organization relate to subsequent reading outcomes? This longitudinal study examined shared reading and white matter organization in kindergarten in relation to subsequent language and reading outcomes among 77 typically developing children. Findings reveal positive associations between the number of hours children are read to weekly (shared reading time) and the fractional anisotropy of the left arcuate fasciculus, as well as left lateralization of the superior longitudinal fasciculus (SLF). Furthermore, left lateralization of the SLF in these kindergarteners is associated with subsequent reading abilities in second grade. Mediation analyses reveal that left lateralization of the SLF fully mediates the relationship between shared reading time and second-grade reading abilities. Results are significant when controlling for age and socioeconomic status. This is the first evidence demonstrating how white matter structure, in relation to shared reading in kindergarten, is associated with school-age reading outcomes. Results illuminate shared reading as a key proxy for the home language and literacy environment and further our understanding of how language interaction may support neurocognitive development.

Risk and resilience correlates of reading among adolescents with language-based learning disabilities during COVID-19

Students with language-based learning disabilities (LBLD) can face elevated socio-emotional well-being challenges in addition to literacy challenges. We examined the prevalence of risk and resilience factors among adolescents with LBLD (N = 93), ages 16-18, and the association with reading performance during the COVID-19 pandemic. Data were collected at the start and end of the first fully remote academic year of COVID-19 (2020-2021). Participants completed standardized word and text reading measures, as well as self-report surveys of executive functions (EF), and socio-emotional skills associated with resilience (grit, growth mindset, self-management, self-efficacy, and social awareness) or risk (anxiety, depression, COVID-19 related PTSD, and perceived COVID-19 impact). Survey data at the start of the school year (Time 1) captured three underlying factors associated with socioemotional risk, socioemotional resilience, and regulation (i.e., EF). Path analyses revealed that students' Time 2 oral reading scores were significantly and uniquely predicted by socioemotional resilience, even when controlling for word-level reading at Time 1. Socioemotional risk, EF, and perceived COVID-19 impact were not directly related to Time 2 oral reading scores; however, students' resilience mediated the associations between risk and reading outcomes. These results demonstrate that adolescents' mental health concerns, self-regulatory ability, and socioemotional resilience were all associated with their experiences of the COVID-19-related stress. However, despite the high-risk context of the pandemic, and socio-emotional challenges faced by students with LBLD, our findings indicate that resilience directly predicts end-of-year reading outcomes and mediates the impact of socioemotional risk on achievement.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11145-022-10361-8.

Patterns of Neural Functional Connectivity in Infants at Familial Risk of Developmental Dyslexia

Importance

Developmental dyslexia is a heritable learning disability affecting 7% to 10% of the general population and can have detrimental impacts on mental health and vocational potential. Individuals with dyslexia show altered functional organization of the language and reading neural networks; however, it remains unknown how early in life these neural network alterations might emerge.

Objective

To determine whether the early emergence of large-scale neural functional connectivity (FC) underlying long-term language and reading development is altered in infants with a familial history of dyslexia (FHD).

Design, Setting, and Participants

This cohort study included infants recruited at Boston Children's Hospital between May 2011 and February 2019. Participants underwent structural and resting-state functional magnetic resonance imaging in the Department of Radiology at Boston Children's Hospital. Infants with FHD were matched with infants without FHD based on age and sex. Data were analyzed from April 2019 to June 2021.

Exposures

FHD was defined as having at least 1 first-degree relative with a dyslexia diagnosis or documented reading difficulties.

Main Outcomes and Measures

Whole-brain FC patterns associated with 20 predefined cerebral regions important for long-term language and reading development were computed for each infant. Multivariate pattern analyses were applied to identify specific FC patterns that differentiated between infants with vs without FHD. For classification performance estimates, 99% CIs were calculated as the classification accuracy minus chance level.

Results

A total of 98 infants (mean [SD] age, 8.5 [2.3] months; 51 [52.0%] girls) were analyzed, including 35 infants with FHD and 63 infants without FHD. Multivariate pattern analyses identified distinct FC patterns between infants with vs without FHD in the left fusiform gyrus (classification accuracy, 0.55 [99% CI, 0.046-0.062]; corrected P < .001; Cohen d = 0.76). Connections linking left fusiform gyrus to regions in the frontal and parietal language and attention networks were among the paths with the highest contributions to the classification performance.

Conclusions and Relevance

These findings suggest that on the group level, FHD was associated with an early onset of atypical FC of regions important for subsequent word form recognition during reading acquisition. Longitudinal studies linking the atypical functional network and school-age reading abilities will be essential to further elucidate the ontogenetic mechanisms underlying the development of dyslexia.

A Cumulative Risk and Resilience Model of Dyslexia

Considerable attention and legislation are currently focused on developmental dyslexia. A major challenge to these efforts is how to define and operationalize dyslexia. In this article, we argue that rather than defining dyslexia on the basis of an underlying condition, dyslexia is best viewed as a label for an unexpected reading disability. This view fits well with a preventive approach in which risk for reading disability is identified and addressed prior to children experiencing reading failure. A risk-resilience model is introduced that proposes that dyslexia is due to the cumulative effects of risk and resilience factors. Evidence for the multifactorial causal basis of dyslexia is reviewed and potential factors that may offset this risk are considered. The implications of a cumulative risk and resilience model for early identification and intervention is discussed.

Association between urinary dialkylphosphate metabolites and dyslexia among children from three cities of China: The READ program

Exposure to organophosphate (OP) insecticides has been found to be related to neurodevelopmental disorders in children. However, no study has examined the association between OP insecticide exposure and the risk of dyslexia among children. We aimed to explore the association between OP insecticide exposure, indicated by urinary dialkylphosphate metabolites (DAPs), and the risk of dyslexia among Chinese Han children from three cities. A total of 845 children (422 dyslexics and 423 non-dyslexics) from Tongji Reading Environment and Dyslexia research program were included in the current case-control study. We measured six DAPs in urine samples, collected from November 2017 to December 2020. Logistic regression models were used to estimate odds ratios (ORs) for the association between DAPs and dyslexia risk, adjusting for potential confounders. The detection frequencies of DAPs were above 97.5%, except for diethyldithiophosphate and dimethyldithiophosphate. Diethyl phosphate metabolites (DEs) were significantly associated with the risk of dyslexia. Compared with the lowest quartile, the adjusted ORs of dyslexia risk for the highest quartile of urinary diethylthiophosphate (DETP) and diethylphosphate (DEP) were 1.82 (1.04, 3.20) and 1.85 (1.08, 3.17), respectively. In addition, the adjusted ORs for dyslexia per 10-fold of urinary DEP, DETP, and ∑DEs concentration were 1.87 (1.12, 3.13), 1.55 (1.03, 2.35), and 1.91 (1.13, 3.21), respectively. Analyses stratified by gender indicated that such associations were more significant among boys. This study suggested that exposure to OP insecticides may be related to dyslexia among Chinese Han children from the three studied cities. However, our results should be interpreted with caution because of the case-control design and the fact that only one-spot urine sample was collected from the children. More studies with children living in China are necessary concerning the relatively high levels of urinary OP metabolites in our study.

Students with dyslexia between school and university: Post-diploma choices and the reasons that determine them. An Italian study

Although the number of students with dyslexia enrolled in Italian universities is constantly growing, their presence remains relatively limited. The aim of this study was therefore to investigate the choices made by students with dyslexia in relation to university studies, and the underlying reasons for their choices. This study also compares these choices for students with and without dyslexia. In all, 440 high school students and their families agreed to take part in this project. Socio-demographic data was collected for the 47 students with dyslexia and 47 class-matched students without dyslexia, along with information on their current schools and their future educational plans. A specially developed questionnaire was used for the students, in combination with structured interviews with their families. The results show significant differences between these groups regarding both choices for university studies and the underlying motivations for these choices. Furthermore, certain psychological and emotional factors are implicated here in the decisions of the students with dyslexia regarding both university studies and their underlying reasons. Future research is needed to further investigate these factors in the educational choices of students with dyslexia.

Direct and Indirect Effects of Blood Levels of Omega-3 and Omega-6 Fatty Acids on Reading and Writing (Dis)abilities

The purpose of the present study was to investigate whether there are associations between polyunsaturated fatty acid (PUFA) blood levels, reading/writing performance and performance in neuropsychological tasks. Moderate to strong correlations were found between PUFA levels (specific omega-6/omega-3 ratios) and reading/writing abilities, and the former and neuropsychological test scores. Mediation models analyzing the direct and indirect effects of PUFA on reading and writing scores showed that the effects of fatty acids on learning measures appear to be direct rather than mediated by the investigated visual and auditory neuropsychological mechanisms. The only significant indirect effect was found for the difference in accuracy between the left and right visual fields in visual-spatial cueing tasks, acting as a mediator for the effect of PUFA ratios on writing accuracy. Regression analyses, by contrast, confirmed the roles of phonological awareness and other visual attentional factors as predictors of reading and writing skills. Such results confirm the crucial role of visual-spatial attention mechanisms in reading and writing, and suggest that visual low-level mechanisms may be more sensitive to the effects of favorable conditions related to the presence of higher omega-3 blood levels.

Reading intervention and neuroplasticity: A systematic review and meta-analysis of brain changes associated with reading intervention

Behavioral research supports the efficacy of intervention for reading disability, but the brain mechanisms underlying improvement in reading are not well understood. Here, we review 39 neuroimaging studies of reading intervention to characterize links between reading improvement and changes in the brain. We report evidence of changes in activation, connectivity, and structure within the reading network, and right hemisphere, frontal and sub-cortical regions. Our meta-analysis of changes in brain activation from pre- to post- reading intervention in eight studies did not yield any significant effects. Methodological heterogeneity among studies may contribute to the lack of significant meta-analytic findings. Based on our qualitative synthesis, we propose that brain changes in response to intervention should be considered in terms of interactions among distributed cognitive, linguistic and sensory systems, rather than via a "normalized" vs. "compensatory" dichotomy. Further empirical research is needed to identify effects of moderating factors such as features of intervention programs, neuroimaging tasks, and individual differences among participants.

The Prevalence and Associated Risk Factors of Children With Reading Disabilities in a Multiethnic City: A Cross-Sectional Study

Numerous studies have been conducted to explore the risk factors for reading disabilities (RDs) among children. Based on these studies, factors such as gender, socioeconomic status, and the home literacy environment have been widely found to be associated with children who have RDs. However, children from a multiethnic city are seldom investigated. This study aimed to explore the prevalence of RDs and the potential environmental risk factors in Shihezi, Xinjiang, where people of multiple ethnicities, including Han and ethnic minority children, live and study together. A cross-sectional study was conducted in the city of Shihezi. A two-stage sampling strategy was applied to randomly select six primary schools in the city. In total, 6,539 students in grades two to six participated in this study. There were 6,065 valid questionnaires obtained for further analyses. We used the Dyslexia Checklist for Chinese Children and the Pupil Rating Scale to screen for the children with RDs. The χ² test and multivariate logistic regression were employed to reveal the potential risk factors of RDs. The prevalence of children with RDs was 3.38% in Shihezi City and was significantly different between Han (3.28%) and Uighur (7.42%) children (P < 0.05). There was no significant difference in the prevalence of RDs between Han and Hui children. Among these children with RDs, the gender ratio of boys to girls was nearly 2:1. Multiple logistic regression analysis showed that gender (P < 0.01), learning habits (P < 0.01), and the home literacy environment (P < 0.01) were associated with RD. The results may be useful in the early identification and intervention of children with RDs, especially among ethnic minorities.

How Learning to Read Changes the Listening Brain

Reading acquisition reorganizes existing brain networks for speech and visual processing to form novel audio-visual language representations. This requires substantial cortical plasticity that is reflected in changes in brain activation and functional as well as structural connectivity between brain areas. The extent to which a child's brain can accommodate these changes may underlie the high variability in reading outcome in both typical and dyslexic readers. In this review, we focus on reading-induced functional changes of the dorsal speech network in particular and discuss how its reciprocal interactions with the ventral reading network contributes to reading outcome. We discuss how the dynamic and intertwined development of both reading networks may be best captured by approaching reading from a skill learning perspective, using audio-visual learning paradigms and longitudinal designs to follow neuro-behavioral changes while children's reading skills unfold.

Kindergarten screening tools filled out by parents and teachers targeting dyslexia. Predictions and developmental trajectories from age 5 to age 15 years

The concept of early 'efforts' has led to discussions for and against introducing language assessment for all kindergarten children. Evidence-based kindergarten screening tools completed by close caregivers could solve this controversy as the children themselves would only be indirectly involved. The aim of this study was to see whether the scores of such early screening tools aiming at developmental dyslexia could predict school marks of literacy competence 10 years later, and to see whether these screening tools would reveal different dyslexia trajectories. The study is part of the Bergen Longitudinal Dyslexia Study, and the results from individual testing are reported elsewhere. Here, the caregivers' views isolated from the rest of the study are focused. Three tools were used: the RI-5, a questionnaire assessing the risk of dyslexia; the TRAS, a non-standardized observation tool of children's communication skills; and the CCC-2, a questionnaire assessing Developmental Language Disorders. Screening was performed at age 5 (TP1), age 11, (TP2) and age 15 (TP3). At TP2, when dyslexia was identified, 13 children formed the dyslexia group, and the rest formed the control group. At TP3, the RI-5 and CCC-2 turned out to be predictive of literacy competence as measured by school marks. Developmental trajectories were seen through the regroupings and scorings into a persistent group, a late onset group and a resolving group. Evidence-based preschool screening tools filled out by close caregivers offer valid information on later literacy developmental trajectories.

The neurocognitive basis of skilled reading in prelingually and profoundly deaf adults

Deaf individuals have unique sensory and linguistic experiences that influence how they read and become skilled readers. This review presents our current understanding of the neurocognitive underpinnings of reading skill in deaf adults. Key behavioural and neuroimaging studies are integrated to build a profile of skilled adult deaf readers and to examine how changes in visual attention and reduced access to auditory input and phonology shape how they read both words and sentences. Crucially, the behaviours, processes, and neural circuity of deaf readers are compared to those of hearing readers with similar reading ability to help identify alternative pathways to reading success. Overall, sensitivity to orthographic and semantic information is comparable for skilled deaf and hearing readers, but deaf readers rely less on phonology and show greater engagement of the right hemisphere in visual word processing. During sentence reading, deaf readers process visual word forms more efficiently and may have a greater reliance on and altered connectivity to semantic information compared to their hearing peers. These findings highlight the plasticity of the reading system and point to alternative pathways to reading success.

Multifactorial pathways facilitate resilience among kindergarteners at risk for dyslexia: A longitudinal behavioral and neuroimaging study

Recent efforts have focused on screening methods to identify children at risk for dyslexia as early as preschool/kindergarten. Unfortunately, while low sensitivity leads to under-identification of at-risk children, low specificity can lead to over-identification, resulting in inaccurate allocation of limited educational resources. The present study focused on children identified as at-risk in kindergarten who do not subsequently develop poor reading skills to specify factors associated with better reading outcomes among at-risk children. Early screening was conducted in kindergarten and a subset of children was tracked longitudinally until second grade. Potential protective factors were evaluated at cognitive-linguistic, environmental, and neural levels. Relative to at-risk kindergarteners with subsequent poor reading, those with typical reading outcomes were characterized by significantly higher socioeconomic status (SES), speech production accuracy, and structural organization of the posterior right-hemispheric superior longitudinal fasciculus (SLF). A positive association between structural organization of the right SLF and subsequent decoding skills was found to be specific to at-risk children and not observed among typical controls. Among at-risk children, several kindergarten-age factors were found to significantly contribute to the prediction of subsequent decoding skills: white matter organization in the posterior right SLF, age, gender, SES, and phonological awareness. These findings suggest that putative compensatory mechanisms are already present by the start of kindergarten. The right SLF, in conjunction with the cognitive-linguistic and socioeconomic factors identified, may play an important role in facilitating reading development among at-risk children. This study has important implications for approaches to early screening, and assessment strategies for at-risk children.

In Search of Cognitive Promotive and Protective Factors for Word Reading

This study examined whether strong cognitive skills (i.e. vocabulary, rapid naming, verbal working memory [VWM], and processing speed [PS]) contributed to resilience in single-word reading skills in children at risk for reading difficulties because of low phonological awareness scores (PA). Promotive factors were identified by main effects and protective factors through PA x cognition interactions. This study included 1,807 children ages 8-16. As predicted, all cognitive skills were significantly related to reading, consistent with promotive effects. A significant, but small effect PA x vocabulary interaction (R2 change=.002, p=.00038) was detected but its form was not consistent with a classic protective effect. Rather, the PA x vocabulary interaction was consistent with a "skill-enhancement" pattern, such that children with strong PA and vocabulary skills had better than expected reading. This study provides a framework for reading resilience research and directs attention to promotive mechanisms underlying reading success.

Putative protective neural mechanisms in prereaders with a family history of dyslexia who subsequently develop typical reading skills

Developmental dyslexia affects 40-60% of children with a familial risk (FHD+) compared to a general prevalence of 5-10%. Despite the increased risk, about half of FHD+ children develop typical reading abilities (FHD+Typical). Yet the underlying neural characteristics of favorable reading outcomes in at-risk children remain unknown. Utilizing a retrospective, longitudinal approach, this study examined whether putative protective neural mechanisms can be observed in FHD+Typical at the prereading stage. Functional and structural brain characteristics were examined in 47 FHD+ prereaders who subsequently developed typical (n = 35) or impaired (n = 12) reading abilities and 34 controls (FHD-Typical). Searchlight-based multivariate pattern analyses identified distinct activation patterns during phonological processing between FHD+Typical and FHD-Typical in right inferior frontal gyrus (RIFG) and left temporo-parietal cortex (LTPC) regions. Follow-up analyses on group-specific classification patterns demonstrated LTPC hypoactivation in FHD+Typical compared to FHD-Typical, suggesting this neural characteristic as an FHD+ phenotype. In contrast, RIFG showed hyperactivation in FHD+Typical than FHD-Typical, and its activation pattern was positively correlated with subsequent reading abilities in FHD+ but not controls (FHD-Typical). RIFG hyperactivation in FHD+Typical was further associated with increased interhemispheric functional and structural connectivity. These results suggest that some protective neural mechanisms are already established in FHD+Typical prereaders supporting their typical reading development.

Exploring the Overlap Between Dyslexia and Speech Sound Production Deficits

Purpose

Children with dyslexia have speech production deficits in a variety of spoken language contexts. In this article, we discuss the nature of speech production errors in children with dyslexia, including those who have a history of speech sound disorder and those who do not, to familiarize speech-language pathologists with speech production-specific risk factors that may help predict or identify dyslexia in young children.

Method

In this tutorial, we discuss the role of a phonological deficit in children with dyslexia and how this may manifest as speech production errors, sometimes in conjunction with a speech sound disorder but sometimes not. We also briefly review other factors outside the realm of phonology that may alert the speech-language pathologist to possible dyslexia.

Results

Speech-language pathologists possess unique knowledge that directly contributes to the identification and remediation of children with dyslexia. We present several clinical recommendations related to speech production deficits in children with dyslexia. We also review what is known about how and when children with speech sound disorder are most at risk for dyslexia.

Conclusion

Speech-language pathologists have a unique opportunity to assist in the identification of young children who are at risk for dyslexia.

Comorbidity of reading disabilities and ADHD: Structural and functional brain characteristics

Reading disabilities (RD) and attention-deficit/hyperactivity disorder (ADHD) are two of the most common developmental disorders. RD and ADHD frequently co-occur, which raises questions about how the disorders interact and to what extent they can be differentiated. To date, the underlying neural mechanisms leading to RD-ADHD comorbidity (COM) are not understood. In this study, structural and functional magnetic resonance imaging (fMRI) were combined with comprehensive behavioral testing in order to characterize the behavior, brain structure, and neural correlates of executive function, phonological processing and reading fluency in 60 children with clinical diagnoses of RD, ADHD, or COM, and controls. Whole-brain analyses of variance were performed on cortical thickness values and on the data of the three fMRI tasks to investigate overall group differences. To validate these findings, a region of interest analysis was performed in regions that have previously been shown to exhibit group differences in children with RD or ADHD using the same paradigms. The neuroimaging results demonstrated structural and functional atypicalities for COM in regions that are frequently associated with deficits in children with isolated ADHD or RD. A combination of shared and distinctive brain alterations between the clinical groups was identified, supporting the multiple deficit model for ADHD, RD, and its comorbidity.

Neural correlates of phonological processing: Disrupted in children with dyslexia and enhanced in musically trained children

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First fMRI investigation of phonological processing in musically trained children.

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Greater bilateral activation with music training in regions disrupted in dyslexia.

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Implications for music training to support compensatory neural network in dyslexia.

Phonological processing has been postulated as a core area of deficit among children with dyslexia. Reduced brain activation during phonological processing in children with dyslexia has been observed in left-hemispheric temporoparietal regions. Musical training has shown positive associations with phonological processing abilities, but the neural mechanisms underlying this relationship remain unspecified. The present research aims to distinguish neural correlates of phonological processing in school-age typically developing musically trained children, musically untrained children, and musically untrained children with dyslexia utilizing fMRI. A whole-brain ANCOVA, accounting for gender and nonverbal cognitive abilities, identified a main effect of group in bilateral temporoparietal regions. Subsequent region-of-interest analyses replicated temporoparietal hypoactivation in children with dyslexia relative to typically developing children. By contrast, musically trained children showed greater bilateral activation in temporoparietal regions when compared to each musically untrained group. Therefore, musical training shows associations with enhanced bilateral activation of left-hemispheric regions known to be important for reading. Findings suggest that engagement of these regions through musical training may underlie the putative positive effects of music on reading development. This supports the hypothesis that musical training may facilitate the development of a bilateral compensatory neural network, which aids children with atypical function in left-hemispheric temporoparietal regions.