Developmental Dyslexia

Unraveling Brain Synchronisation Dynamics by Explainable Neural Networks using EEG Signals: Application to Dyslexia Diagnosis

The electrical activity of the neural processes involved in cognitive functions is captured in EEG signals, allowing the exploration of the integration and coordination of neuronal oscillations across multiple spatiotemporal scales. We have proposed a novel approach that combines the transformation of EEG signal into image sequences, considering cross-frequency phase synchronisation (CFS) dynamics involved in low-level auditory processing, with the development of a two-stage deep learning model for the detection of developmental dyslexia (DD). This deep learning model exploits spatial and temporal information preserved in the image sequences to find discriminative patterns of phase synchronisation over time achieving a balanced accuracy of up to 83%. This result supports the existence of differential brain synchronisation dynamics between typical and dyslexic seven-year-old readers. Furthermore, we have obtained interpretable representations using a novel feature mask to link the most relevant regions during classification with the cognitive processes attributed to normal reading and those corresponding to compensatory mechanisms found in dyslexia.

Training rapid automatized naming in children with developmental Dyslexia

The recommended rehabilitation procedures for Developmental Dyslexia (DD) are not well defined, and there is currently a large debate on which therapeutic approaches are shown to be more useful and effective. Among the trainings focused on general dysfunctional cognitive processes associated with a reading disorder, recent studies suggested the efficacy of trainings on Rapid Automatized Naming (RAN) compared to others. The present study was aimed at confirming the effectiveness of RAN training (RANt) to improve the reading performances of children with DD (n = 32) compared to children on a waiting list (WL, n = 25) and to children in different treatment groups, one following a text reading training (RT, n = 26) and the other combining RAN and text reading exercises (RANt+RT, n = 20), through an online platform that allows intensive and self-adaptive activities. Results confirmed the efficacy of RANt in improving reading speed and accuracy compared to the WL group (r2 ranging from small (.16) to medium (.48)) and found the absence of differences with the other active control groups. The single-subject level analysis confirmed the results, a high inter-subject variability in treatment response and pre-post differences were found. Further studies could consider such variability in the functional profile of the DD subjects, but RANt was confirmed to be a valid tool for improving decoding skills.

Contrasting Deficits in the Function of the Phonological Loop Between Children With Attention Deficit Hyperactivity Disorder and Reading Disability

Attention Deficit Hyperactivity Disorder (ADHD) and reading disability (RD) often co-occur. Impairments in the phonological loop of working memory are central to RD, but it is unclear whether this is linked to ADHD, especially in Chinese reading. Two experiments were conducted with Chinese children aged 7 to 12 (Experiment 1, n = 65; Experiment 2, n = 60). Immediate and delayed recognition paradigms were used to assess phonological encoding and rehearsal. Both the RD-only and comorbid (ADHD + RD) groups performed worse than the control and ADHD-only groups in response time and accuracy. Notably, the comorbid group performed similarly to the RD-only group, indicating that phonological loop deficits in comorbid children are likely due to RD, not ADHD. This highlights phonological loop function as the key to distinguishing between ADHD and RD.

The role of sound-to-symbol literacy in phonological awareness: Evidence from Cantonese

Phonological awareness reflects linguistic knowledge related to the sound system of a language. Individual development of phonological awareness is known to progress from larger to smaller sized units and is promoted by the acquisition of literacy, especially in alphabet-based writing systems that are built around sound-to-symbol correspondences. The present study addressed the nature of phonological awareness in speakers of a logographically scripted language. It investigated phonological awareness in adult speakers of Cantonese hailing from Hong Kong who (compared to speakers of other logographically scripted languages) traditionally received little sound-based assistance from tools like Pinyin or Zhu-yin-Fu-Hao when they acquired orthography. The study adopted an individual difference approach, quantifying individually variable levels of experience with a sound-to-symbol writing system and their relationship to phonological awareness. Fifty-seven Hong-Kong speakers of Cantonese took part online, completing rhyme judgment and phoneme monitoring tasks, alongside an extensive background questionnaire. The main prediction that Cantonese speakers who had a relatively high level of experience with sound-to-symbol writing would show an advantage in phonological awareness at the subsyllabic level was largely borne out by the data. The findings of the present study suggest that phonological awareness is a complex set of dissociable skills, shaped by the linguistic and orthographic experience of individual speakers.

Prevalence of developmental dyslexia among primary school children in Arab countries: a systematic review and meta-analysis

BACKGROUND

Dyslexia is one of the most common learning disabilities. It poses challenges in reading skills development and can have a lasting impact in other areas of learning.

AIMS

To investigate the prevalence of developmental dyslexia among primary school children aged 6-13 in Arab countries, and to explore associations with gender and residency.

METHOD

Following the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines, we included studies up to December 2023 that were found in English and Arabic research database searches. Random-effects proportional meta-analyses determined the prevalence of dyslexia in Arab countries, with a direct comparison between girls and boys using odds ratios.

RESULTS

The meta-analysis included 18 studies with 30,243 participants: eight studies (44 %) from Egypt, four (22 %) from Saudi Arabia, and six (34 %) from other Arab countries. The pooled prevalence of dyslexia for children aged 6-13 in these studies was 11 %. The odds ratio for girls vs. boys was 0.85 (95 %). Geographical variations were notable, with eight studies (44 %) from Asia and ten (56 %) from Africa. Eight studies (44 %) were from the Gulf region, while ten (56 %) were from non-Gulf region. Prevalence of dyslexia was significantly higher in Arab countries in Asia (24 %) than in Africa (12 %), and the prevalence in non-Gulf countries was 13 % which was nearly half in comparison to Gulf countries (24 %).

CONCLUSIONS

The prevalence rates of dyslexia in primary school children varies across the Arab world, with higher rates among boys, Arab countries in Asia, and Gulf countries. Further research is needed to include both genders and standardized diagnostics across more Arab countries to understand and address dyslexia effectively.

The neoliberal leaning of the neuroscience discourse when it deals with mental health and learning disorders

Neuroscience attracted increasing attention in mass media during the last decades. Indeed, neuroscience advances raise high expectations in society concerning major societal issues such as mental health and learning difficulties. Unfortunately, according to leading experts, neuroscience advances have not yet benefited patients, students and socially deprived families. Yet, neuroscience findings are widely overstated and misrepresented in the media. Academic studies, briefly described here, showed that most data misrepresentations were already present in the neuroscience literature before spreading in mass media. This triumphalist neuroscience discourse reinforces a neuro-essentialist conception of mental disorders and of learning difficulties. By emphasizing brain plasticity, this discourse fuels the neoliberal ethics that overvalue autonomy, rationality, flexibility and individual responsibility. According to this unrealistic rhetoric, neuroscience-based techniques will soon bring inexpensive private solutions to enduring social problems. When considering the social consequences of this rhetoric, neuroscientists should refrain from overstating the interpretation of their observations in their scientific publications and in their exchanges with journalists.

Brain Laterality in Dyslexia Seen during Literacy Development and Early Training

During the period in which children learn to read and write, a gradual shift from right to left hemisphere dominance for language is typically seen. However, in children with dyslexia, a deviant pattern is described in the literature. As part of a larger longitudinal study (The Bergen Longitudinal Dyslexia Study), the present study aimed to assess this development from an early age before children learn to read and write. Dichotic listening (DL), which is a non-invasive test, was used to assess the development of brain laterality in a Typical group and a Dyslexia group. The participants received yearly sessions of evidence-based literacy training at ages 5 to 7. The Typical group showed increasing ear scores and a shift from no ear advantage in the Pre-literacy stage (age 6), indicative of no hemisphere dominance, to a right ear advantage, indicative of a left hemisphere dominance, in the Emergent literacy stage (age 8) and the Literacy stage (age 11). The Dyslexia group showed a different pattern, with a significant right ear advantage at age 6, indicative of a right hemisphere dominance, and increasing ear scores at ages 8 and 11; however, no ear dominance was observed in the Literacy stage. The results point to an effect of relevant, evidence-based training affecting both right and left hemispheres in dyslexia, which should form a basis for further research.

White matter substrates underlying morphological awareness deficit in Chinese children with developmental dyslexia

BACKGROUND

Morphological awareness (MA) deficit is strongly associated with Chinese developmental dyslexia (DD). However, little is known about the white matter substrates underlying the MA deficit in Chinese children with DD.

METHODS

In the current study, 34 Chinese children with DD and 42 typical developmental (TD) children were recruited to complete a diffusion magnetic resonance imaging scan and cognitive tests for MA. We conducted linear regression to test the correlation between MA and DTI metrics, the structural abnormalities of the tracts related to MA, and the interaction effect of DTI metrics by group on MA.

RESULTS

First, MA was significant related to the right inferior occipito-frontal fascicle (IFO) and inferior longitudinal fsciculus (ILF), the bilateral thalamo-occipital (T_OCC) and the left arcuate fasciculus (AF); second, compared to TD children, Chinese children with DD had lower axial diffusivity (AD) in the right IFO and T_OCC; third, there were significant interactions between metrics (fractional anisotropy (FA) and radial diffusivity (RD)) of the right IFO and MA in groups. The FA and RD of the right IFO were significantly associated with MA in children with DD but not in TD children.

CONCLUSION

In conclusion, compared to TD children, Chinese children with DD had axonal degeneration not only in the ventral tract (the right IFO) but also the visuospatial tract (the right T_OCC) which were associated with their MA deficit. And Chinese MA involved not only the ventral tracts, but also the visuospatial pathway and dorsal tracts.

Shared and task-specific brain functional differences across multiple tasks in children with developmental dyslexia

Different tasks have been used in examining the neural functional differences associated with developmental dyslexia (DD), and consequently, different findings have been reported. However, very few studies have systematically compared multiple tasks in understanding what specific task differences each brain region is associated with. In this study, we employed an auditory rhyming task, a visual rhyming task, and a visual spelling task, in order to investigate shared and task-specific neural differences in Chinese children with DD. First, we found that children with DD had reduced activation in the opercular part of the left inferior frontal gyrus (IFG) only in the two rhyming tasks, suggesting impaired phonological analysis. Children with DD showed functional differences in the right lingual gyrus/inferior occipital gyrus only in the two visual tasks, suggesting deficiency in their visuo-orthographic processing. Moreover, children with DD showed reduced activation in the left dorsal inferior frontal gyrus and increased activation in the right precentral gyrus across all of the three tasks, suggesting neural signatures of DD in Chinese. In summary, our study successfully separated brain regions associated with differences in orthographic processing, phonological processing, and general lexical processing in DD. It advances our understanding about the neural mechanisms of DD.

Telerehabilitation of Developmental Dyslexia: Critical Considerations on Intervention Methods and Their Effectiveness

Paper-based or IT tools can be used in telerehabilitation mode to improve the skills of children with developmental dyslexia (DD), seeking to increase reading speed and reduce errors. Telerehabilitation is the provision of remote treatments in which the patient works autonomously in a familiar environment under the remote monitoring, through telecommunication means, of an expert operator. Through telerehabilitation, children with DD can receive treatments outside the specialist clinic, at home or school, via internet connections, and through advanced technological platforms. These procedures allow adequate communication with the family, intensity of treatment, self-adaptivity of exercises, and child engagement; these factors are crucial for a high intervention efficacy. Recent studies have supported the effectiveness of the telerehabilitation of reading in children with DD, with some studies reporting no differences in efficacy between remote and in-person methods. Nevertheless, many points remain to be clarified about the procedures and methods required by telerehabilitation, the variables linked to its effectiveness (e.g., the impact of the intensity of the training and the neuropsychological profile of the child), and the comparative validity of different tele-treatment paths. These aspects are discussed in the present paper.

Reading skills over time among children with Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is an X-linked progressive neuromuscular disorder with a distinct cognitive profile including decreased verbal span. Children with DMD are also at risk for lower scores on academic achievement tests and increased behavioral problems. Longitudinal analyses generally reveal a stable intellectual profile, although attention and behavioral problems may negatively impact longitudinal IQ scores. To date, no study has reported on reading over time in DMD. Reading performance was assessed longitudinally in children with DMD, examining for potential contributions to the trajectory. Retrospective data analysis on assessments completed at baseline, year 2, and year 4 on 26 boys with DMD and 27 unaffected sibling controls (age at baseline: DMD 8 ± 1.4, controls 9 ± 2.6) indicated that children with DMD performed slightly, yet significantly, worse than controls on reading skills, but the longitudinal trajectory of reading skills for children with DMD and controls was not significantly different. Verbal span at time 1 was uniquely associated with later reading skills in children with DMD. Behavior was not associated with declines. The results confirm that children with DMD underperform on reading tasks and align with previous research suggesting that cognitive skills in DMD are stable over time.

Effects of a visual perception-based occupational therapy program on reading and motor skills in children with developmental dyslexia: Single blind randomized cross-over study design

This study aimed to examine the effects of a visual praxis-based occupational therapy (VPOT) program on reading and motor skills for children with developmental dyslexia (DD). Forty-two children were included in the study. Additionally, before VPOT, the Reading-Aloud and Reading-Comprehension Test 2 (ORSRC-2) and the Bruininks-Oseretsky Motor-Proficiency-Test-2-Brief Form (BOT2-BF) were applied to the participants. According to the study design, VPOT was applied to two sessions per week for 8 weeks to group A. During this period, group B was accepted as the control group. At the end of these 8 weeks, evaluation tests were applied to both groups. Then, group A was defined as the control group and Group B as the intervention group, and VPOT was applied to Group B. At the end of another 8 weeks, evaluation tests were applied to both groups for the third time. When the final ORSRC-2 results were examined, VPOT was found to be an effective program for improving reading skills. Additionally, when the final BOT2-BF results were examined, VPOT was determined to be effective in improving motor skills (p < 0.05). We believe that it is important to carry out comprehensive studies such as the VPOT program to solve problems in the physical and learning activities of children with DD.

Predicting Response to Neuropsychological Intervention in Developmental Dyslexia: A Retrospective Study

Identifying the patients who are likely to be non-responders to a certain treatment may allow clinicians to provide alternative strategies and avoid frustration and unrealistic expectations for the patients and their families. A retrospective study on 145 children treated with visual hemisphere-specific stimulation examined the specific profiles (reading, writing, metaphonology, memory, callosal functions) of non-responders, and identified predictors of response to intervention (reading, reading and writing) through linear regression models. The effects of additional variables such as rapid automatized naming (RAN) and Visual Search were investigated in a subsample of 48 participants. Subgroups related to gender and dyslexia subtype were considered in the analyses. The results highlight an Intervention Differential Effect (IDE) not depending on regression to the mean and mathematical coupling effects. The characteristics of non-responders for reading seem to correspond children with mild reading and severe writing impairments; non-responders for reading and writing are those with impaired callosal transfer. Predictors of overall response to intervention were pre-test reading and writing scores; phoneme blending, accuracy in visual search and speed in rapid automatized naming contributed to explaining response variance. Specific predictors for female vs. male participants and dyslexia subtypes were identified.

Screening for Dyslexia in University Students: a Standardized Procedure Based on Conditional Inference Trees

OBJECTIVE

The focus of this study is on providing tools to enable researchers and practitioners to screen for dyslexia in adults entering university. The first aim is to validate and provide diagnostic properties for a set of seven tests including a 1-min word reading test, a 2-min pseudoword reading test, a phonemic awareness test, a spelling test, the Alouette reading fluency test, a connected-text reading fluency test, and the self-report Adult Reading History Questionnaire (ARHQ). The second, more general, aim of this study was to devise a standardized and confirmatory procedure for dyslexia screening from a subset of the initial seven tests. We used conditional inference tree analysis, a supervised machine learning approach to identify the most relevant tests, cut-off scores, and optimal order of test administration.

METHOD

A combined sample of 60 university students with dyslexia (clinical validation group) and 65 university students without dyslexia (normative group) provided data to determine the diagnostic properties of these tests including sensitivity, specificity, and cut-off scores.

RESULTS

Results showed that combinations of four tests (ARHQ, text reading fluency, phonemic awareness, pseudoword reading) and their relative conditional cut-off scores optimize powerful discriminatory screening procedures for dyslexia, with an overall classification accuracy of approximately 90%.

CONCLUSIONS

The novel use of the conditional inference tree methodology explored in the present study offered a way of moving toward a more efficient screening battery using only a subset of the seven tests examined. Both clinical and theoretical implications of these findings are discussed.

Alterations in neural activation in the ventral frontoparietal network during complex magnocellular stimuli in developmental dyslexia associated with READ1 deletion

BACKGROUND

An intronic deletion within intron 2 of the DCDC2 gene encompassing the entire READ1 (hereafter, READ1d) has been associated in both children with developmental dyslexia (DD) and typical readers (TRs), with interindividual variation in reading performance and motion perception as well as with structural and functional brain alterations. Visual motion perception -- specifically processed by the magnocellular (M) stream -- has been reported to be a solid and reliable endophenotype of DD. Hence, we predicted that READ1d should affect neural activations in brain regions sensitive to M stream demands as reading proficiency changes.

METHODS

We investigated neural activations during two M-eliciting fMRI visual tasks (full-field sinusoidal gratings controlled for spatial and temporal frequencies and luminance contrast, and sensitivity to motion coherence at 6%, 15% and 40% dot coherence levels) in four subject groups: children with DD with/without READ1d, and TRs with/without READ1d.

RESULTS

At the Bonferroni-corrected level of significance, reading skills showed a significant effect in the right polar frontal cortex during the full-field sinusoidal gratings-M task. Regardless of the presence/absence of the READ1d, subjects with poor reading proficiency showed hyperactivation in this region of interest (ROI) compared to subjects with better reading scores. Moreover, a significant interaction was found between READ1d and reading performance in the left frontal opercular area 4 during the 15% coherent motion sensitivity task. Among subjects with poor reading performance, neural activation in this ROI during this specific task was higher for subjects without READ1d than for READ1d carriers. The difference vanished as reading skills increased.

CONCLUSIONS

Our findings showed a READ1d-moderated genetic vulnerability to alterations in neural activation in the ventral attentive and salient networks during the processing of relevant stimuli in subjects with poor reading proficiency.

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.

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.

Infant mismatch responses to speech-sound changes predict language development in preschoolers at risk for dyslexia

OBJECTIVE

We investigated how infant mismatch responses (MMRs), which have the potential for providing information on auditory discrimination abilities, could predict subsequent development of pre-reading skills and the risk for familial dyslexia.

METHODS

We recorded MMRs to vowel, duration, and frequency deviants in pseudo-words at birth and 28 months in a sample over-represented by infants with dyslexia risk. We examined MMRs' associations with pre-reading skills at 28 months and 4-5 years and compared the results in subgroups with vs. without dyslexia risk.

RESULTS

Larger positive MMR (P-MMR) at birth was found to be associated with better serial naming. In addition, increased mismatch negativity (MMN) and late discriminative negativity (LDN), and decreased P-MMR at 28 months overall, were shown to be related to better pre-reading skills. The associations were influenced by dyslexia risk, which was also linked to poor pre-reading skills.

CONCLUSIONS

Infant MMRs, providing information about the maturity of the auditory system, are associated with the development of pre-reading skills. Speech-processing deficits may contribute to deficits in language acquisition observed in dyslexia.

SIGNIFICANCE

Infant MMRs could work as predictive markers of atypical linguistic development during early childhood. Results may help in planning preventive and rehabilitation interventions in children at risk of learning impairments.

Speech-to-text intervention to support text production among students with writing difficulties: a single-case study in nordic countries

Studies report that speech-to-text applications (STT) may support students with writing difficulties in text production. However, existing research is sparse, shows mixed results, and lacks information on STT interventions and their applicability in schools. Therefore, this study aimed to investigate whether a systematic and intensive assistive technology intervention focusing on STT can improve text production. A modified multiple-baseline across-subject design was used involving eight middle school students, four Norwegian and four Swedish. Their STT-produced narrative texts were collected during and after the intervention and the productivity, accuracy, and text quality were analysed. Keyboarding was the baseline control condition. The results demonstrated that seven of the eight students increased text productivity and that the proportion of word-level accuracy was maintained or improved. The use of punctuation progressed in participants with poor baseline skills. Most students' STT-produced texts had at least a similar ratio of meaningfulness and text quality as keyboarding. However, the magnitude of the changes and development patterns varied, with three students showing the most notable impacts. In conclusion, this study's intervention seemed beneficial in initially instructing STT, and the progress monitoring guided individually adapted future interventions such as balancing productivity and formal language aspects. Removing the spelling barrier with STT provided an opportunity for students to improve their higher-order skills, such as vocabulary diversity and overall text quality. Furthermore, visible progress, such as the ability to produce longer texts, might motivate continued STT usage. However, such development may not always be immediate.

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.

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.

Dyslexic students' experiences in using assistive technology to support written language skills: a five-year follow-up

PURPOSE

This study presents several accounts of user experiences with assistive technology (AT). Although previous studies on dyslexic students reported promising results from using audiobooks, text-to-speech (TTS), and speech-to-text (STT), qualitative research is relatively sparse and short-term, and little is known about adolescents' long-term experiences of using AT in schools. Therefore, this five-year follow-up study aimed to describe dyslexic students' experiences of AT.

MATERIALS AND METHODS

Nine students with dyslexia were interviewed using a semi-structured framework and a descriptive pattern-based thematic analysis. The students had previously participated in an AT intervention in Sweden.

RESULTS

Three main themes are reported: Contextual factors: facilitators or barriers; Emotional responses in the learning environment; Developing meaningful strategies. The results align with previous research findings that audiobooks are beneficial throughout the school years, while STT is of mixed utility. TTS was mainly used in learning to decode texts. Continued AT use is discussed thematically, concretising experiences connected to schools' multilevel support.

CONCLUSIONS

This study can contribute to the development of AT academic practices enriched by users' views. The findings reveal factors enabling or hindering students' continued AT usage. Contextual factors in schools concern organisational elements rather than AT accessibility. Students' emotional responses (using AT in the classroom) are influenced by dyslexia self-acceptance and AT attitudes. Students' understanding of how and why to use AT may limit the development of meaningful strategies. Implications and suggested further research are provided to improve dyslexic students' AT experiences and success in school.

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.

Association of exposure to phthalates and phthalate alternatives with dyslexia in Chinese primary school children

Previous studies have shown associations between children's exposure to phthalates and neurodevelopmental disorders. Whereas the impact of exposure to phthalate alternatives is understudied. This study aimed to evaluate the association of exposure to phthalates/their alternatives with the risk of dyslexia. We recruited 745 children (355 dyslexia and 390 non-dyslexia) via the Tongji Reading Environment and Dyslexia Research Project, and their urine samples were collected. A total of 26 metabolites of phthalates/their alternatives were measured. Multivariate logistic regression and quantile-based g-computation were used to estimate the associations of exposure to the phthalates/their alternatives with dyslexia. More than 80% of the children had 17 related metabolites detected in their urine samples. After adjustment, the association between mono-2-(propyl-6-hydroxy-heptyl) phthalate (OH-MPHP) with the risk of dyslexia was observed. Compared with the lowest quartile of OH-MPHP levels, the odds of dyslexia for the third quartile was 1.93 (95% CI 1.06, 3.57). Regarding mixture analyses, it was found that OH-MPHP contributed the most to the association. Further analyses stratified by sex revealed that this association was only observed in boys. Our results suggested a significantly adverse association of di-2-propylheptyl phthalate exposure with children's language abilities. It highlights the necessity to prioritize the protection of children's neurodevelopment by minimizing their exposure to endocrine-disrupting chemicals like di-2-propylheptyl phthalate.

Unraveling individual differences in learning potential: A dynamic framework for the case of reading development

Children show an enormous capacity to learn during development, but with large individual differences in the time course and trajectory of learning and the achieved skill level. Recent progress in developmental sciences has shown the contribution of a multitude of factors including genetic variation, brain plasticity, socio-cultural context and learning experiences to individual development. These factors interact in a complex manner, producing children's idiosyncratic and heterogeneous learning paths. Despite an increasing recognition of these intricate dynamics, current research on the development of culturally acquired skills such as reading still has a typical focus on snapshots of children's performance at discrete points in time. Here we argue that this 'static' approach is often insufficient and limits advancements in the prediction and mechanistic understanding of individual differences in learning capacity. We present a dynamic framework which highlights the importance of capturing short-term trajectories during learning across multiple stages and processes as a proxy for long-term development on the example of reading. This framework will help explain relevant variability in children's learning paths and outcomes and fosters new perspectives and approaches to study how children develop and learn.

Are Communication Skills, Emotion Regulation and Theory of Mind Skills Impaired in Adolescents with Developmental Dyslexia?

This study investigates pragmatic language impairment, Theory of Mind (ToM), and emotion regulation in adolescents with Developmental Dyslexia(DD). The Social Responsiveness Scale-2(SRS) and Children's Communication Checklist-2(CCC-2) scores were found to be statistically significantly higher in the DD group than in healthy controls. DD group had lower performance in ToM skills and they have more difficulties in emotion regulation. We also found that CCC-2 and ToM scores were significantly correlated in adolescents with DD. These results may be important in understanding the difficulties experienced in social functioning and interpersonal relationships in adolescents with DD.

Investigating Dyslexia through Diffusion Tensor Imaging across Ages: A Systematic Review

Dyslexia is a neurodevelopmental disorder that presents a deficit in accuracy and/or fluency while reading or spelling that is not expected given the level of cognitive functioning. Research indicates brain structural changes mainly in the left hemisphere, comprising arcuate fasciculus (AF) and corona radiata (CR). The purpose of this systematic review is to better understand the possible methods for analyzing Diffusion Tensor Imaging (DTI) data while accounting for the characteristics of dyslexia in the last decade of the literature. Among 124 articles screened from PubMed and Scopus, 49 met inclusion criteria, focusing on dyslexia without neurological or psychiatric comorbidities. Article selection involved paired evaluation, with a third reviewer resolving discrepancies. The selected articles were analyzed using two topics: (1) a demographic and cognitive assessment of the sample and (2) DTI acquisition and analysis. Predominantly, studies centered on English-speaking children with reading difficulties, with preserved non-verbal intelligence, attention, and memory, and deficits in reading tests, rapid automatic naming, and phonological awareness. Structural differences were found mainly in the left AF in all ages and in the bilateral superior longitudinal fasciculus for readers-children and adults. A better understanding of structural brain changes of dyslexia and neuroadaptations can be a guide for future interventions.

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.

Exposure to organophosphate, pyrethroid, and neonicotinoid insecticides and dyslexia: Association with oxidative stress

Organophosphates (OPPs), pyrethroids (PYRs), and neonicotinoids (NNIs) are three major classes of insecticides used worldwide. They might compromise child neurodevelopment. However, few studies have explored the association between exposure to them and dyslexia. The present study aimed to investigate the association between dyslexia and exposure to the three classes of insecticides, as well as explore the potential role of oxidative stress in the association. A total of 355 dyslexic children and 390 controls were included in this study. The exposure biomarkers were determined by liquid chromatography-tandem mass spectrometry. Specifically, the exposure biomarkers included three typical metabolites of OPPs, three of PYRs, and nine of NNIs. Additionally, three typical oxidative stress biomarkers, namely, 8-hydroxy-2'-deoxyguanosine (8-OHdG) for DNA damage, 8-hydroxyguanosine (8-OHG) for RNA damage, and 4-hydroxy-2-nonenal-mercapturic acid (HNEMA) for lipid peroxidation were measured. The detection frequencies of the urinary biomarkers ranged from 83.9% to 100%. Among the target metabolites of the insecticides, a significant association was observed between urinary 3,5,6-trichloro-2-pyridinol (TCPy, the metabolite of chlorpyrifos, an OPP insecticide) and dyslexia. After adjusting for potential confounding variables, children in the highest quartile of TCPy levels had an increased odds of dyslexia (odds ratio [OR], 1.68; 95% confidence interval [CI]: 1.03, 2.75] in comparison to those in the lowest quartile. Among the three oxidative stress biomarkers, urinary HNEMA concentration showed a significant relationship with dyslexia. Children in the highest quartile of HNEMA levels demonstrated an increased dyslexic odds in comparison to those in the lowest quartile after multiple adjustments (OR, 1.64; 95% CI: 1.01, 2.65). Mediation analysis indicated a significant effect of HNEMA in the association between urinary TCPy and dyslexia, with an estimate of 17.2% (P < 0.01). In conclusion, this study suggested the association between urinary TCPy and dyslexia. The association could be attributed to lipid peroxidation partially.

Rules generalization in children with dyslexia

BACKGROUND

Rule learning (RL) is the ability to extract and generalize higher-order repetition-based structures. Children with Developmental Dyslexia (DD) often report difficulties in learning complex regularities in sequential stimuli, which might be due to the complexity of the rule to be learned. Learning high-order repetition-based rules represents a building block for the development of language skills.

AIMS

This study investigates the ability to extract and generalize simple, repetition-based visual rules (e.g., ABA) in 8-11-year-old children without (TD) and with a diagnosis of Development Dyslexia (DD) and its relationship with language and reading skills.

METHOD

Using a forced-choice paradigm, children were first exposed to a visual sequence containing a repetition-based rule (e.g., ABA) and were then asked to recognize familiar and novel rules generated by new visual elements. Standardized language and reading tests were also administered to both groups.

RESULTS

The accuracy in recognizing rules was above chance for both groups, even though DD children were less accurate than TD children, suggesting a less efficient RL mechanism in the DD group. Moreover, visual RL was positively correlated with both language and reading skills.

CONCLUSION

These results further confirm the crucial role of RL in the acquisition of linguistic skills and mastering reading abilities.

The Association of Speech/Language Risk With Phonological Awareness, Rapid Naming, and Reading Ability in Children With Cleft Lip and/or Palate

Children with cleft lip and/or palate were assessed for speech, language, phonological awareness (PA), rapid naming (RN) and reading ability using standardized instruments at baseline (T1; N = 142, Mage = 6.14 years, 51% males) and 2-year follow-up (T2; 89% retention, Mage = 8.38). Children with no speech or language risk scored higher for T1 and T2 PA, RN, and reading than children with both speech and language risk [Adjusted Mean Difference (AMD) ranged from 11.79 to 21.25]; language risk (AMD 8.37 to 13.58); and speech risk (0.51 to 6.87). No significant differences by cleft type or child sex.

The challenge of remote treatment in neuropsychological intervention for reading and spelling in dyslexia: A prospective observational cohort study

Telemedicine approaches have proved to be valuable solutions for the delivery of treatment for many health-related issues, and crucial during the pandemics. Nonetheless, the efficacy of such Web-based practices in developmental dyslexia needs to be thoroughly evaluated. To this aim, the effects of a multi-componential program for neuropsychological intervention in dyslexia delivered as an outpatient program were compared with those obtained with a remotely delivered, Web-based treatment, based on the same methodological principles and delivered with the same duration and intensity. The treatment-related changes obtained with a combination of visual hemisphere-specific stimulation and training of visual-spatial attention through action video games, were compared to those obtained through remote treatment via the Tachidino Web-based platform. Both treatments had a duration of 4 weeks. The same battery of reading and phonemic awareness tests was delivered in presence, before and after treatment, as well as at 6-months follow-up. User satisfaction was assessed through parents and user questionnaires. Both treatments were significantly and similarly effective in improving reading speed, reading accuracy, and writing accuracy. No reduction in the effects was observed after treatment discontinuation. The Web-based treatment may thus offer a valid alternative to in-person intervention, optimizing the flexibility, capillary diffusion and cost-effectiveness of intervention.

Phonological deficits in dyslexia impede lexical processing of spoken words: Linking behavioural and MEG data

Phonological difficulties have been identified as a core deficit in developmental dyslexia, yet everyday speech comprehension, which relies on phonological processing, is seemingly unaffected. This raises the question as to how dyslexic readers process spoken words to achieve normal word comprehension. Here we establish a link between neural correlates of lexical and sublexical processing in auditory words and behaviourally measured phonological deficits using magnetoencephalography (MEG). Spatiotemporally resolved cortical responses to phonological and lexico-semantic information were computed with the event-related regression technique (Hauk et al., 2009) and correlated with dyslexic and non-dyslexic subjects' phonological skills. We found that phonological deficits reduced cortical responses to both phonological and lexico-semantic information (phonological neighbours and word frequency). Individuals with lower phonological skills - independent of dyslexia diagnosis - showed weaker neural responses to phonological neighbourhood information in both hemispheres 200-500 ms after word onset and reduced sensitivity to written and spoken word frequency between 200 and 650 ms. Dyslexic readers showed weaker responses to written word frequency in particular compared to the control group, pointing towards an additional effect of print exposure on auditory word processing. Source space analysis localised phonological and lexico-semantic effect peaks to the left superior temporal gyrus, a key area that has been related to core deficits in dyslexia across a range of neuroimaging studies. The results provide comprehensive evidence that phonological deficits impact both sublexical and lexical stages of spoken word processing and that these deficits cannot be fully compensated through neural re-organization of lexical-distributional information at the single word level. Theoretical and practical implications for typical readers, dyslexic readers, and readers with developmental language disorder are discussed.

Developmental Dyslexia: Insights from EEG-Based Findings and Molecular Signatures-A Pilot Study

Developmental dyslexia (DD) is a learning disorder. Although risk genes have been identified, environmental factors, and particularly stress arising from constant difficulties, have been associated with the occurrence of DD by affecting brain plasticity and function, especially during critical neurodevelopmental stages. In this work, electroencephalogram (EEG) findings were coupled with the genetic and epigenetic molecular signatures of individuals with DD and matched controls. Specifically, we investigated the genetic and epigenetic correlates of key stress-associated genes (NR3C1, NR3C2, FKBP5, GILZ, SLC6A4) with psychological characteristics (depression, anxiety, and stress) often included in DD diagnostic criteria, as well as with brain EEG findings. We paired the observed brain rhythms with the expression levels of stress-related genes, investigated the epigenetic profile of the stress regulator glucocorticoid receptor (GR) and correlated such indices with demographic findings. This study presents a new interdisciplinary approach and findings that support the idea that stress, attributed to the demands of the school environment, may act as a contributing factor in the occurrence of the DD phenotype.

Remote treatment of developmental dyslexia: how ADHD comorbidity, clinical history and treatment repetition may affect its efficacy

Introduction

Tachidino is a web-based platform for remote treatment of reading and spelling disorders. The purpose of the present study was to investigate the possible impact of different clinical conditions on the efficacy of treatment. The focus was on possible ADHD comorbidity-related effects on the outcomes of the Tachidino treatment, and the impact of previous treatments, such as speech and language therapy or the repetition of the same Tachidino program.

Methods

136 children with developmental dyslexia received four-weeks treatment via the Tachidino platform. Improvements in reading and writing scores were compared between different subgroups.

Results

No gross differences emerged in treatment effectiveness between groups of children. Children receiving treatment improved significantly more than untreated children.

Discussion

Treatment with Tachidino brought significant benefits for all children, irrespective of comorbidity, clinical history or treatment repetition. Comparison with an untreated control group (waiting list) made it possible to exclude that improvement was due to test-retest learning effects.

Sensory temporal sampling in time: an integrated model of the TSF and neural noise hypothesis as an etiological pathway for dyslexia

Much progress has been made in research on the causal mechanisms of developmental dyslexia. In recent years, the "temporal sampling" account of dyslexia has evolved considerably, with contributions from neurogenetics and novel imaging methods resulting in a much more complex etiological view of the disorder. The original temporal sampling framework implicates disrupted neural entrainment to speech as a causal factor for atypical phonological representations. Yet, empirical findings have not provided clear evidence of a low-level etiology for this endophenotype. In contrast, the neural noise hypothesis presents a theoretical view of the manifestation of dyslexia from the level of genes to behavior. However, its relative novelty (published in 2017) means that empirical research focused on specific predictions is sparse. The current paper reviews dyslexia research using a dual framework from the temporal sampling and neural noise hypotheses and discusses the complementary nature of these two views of dyslexia. We present an argument for an integrated model of sensory temporal sampling as an etiological pathway for dyslexia. Finally, we conclude with a brief discussion of outstanding questions.

Auditory attention influences trajectories of symbol-speech sound learning in children with and without dyslexia

The acquisition of letter-speech sound correspondences is a fundamental process underlying reading development, one that could be influenced by several linguistic and domain-general cognitive factors. In the current study, we mimicked the first steps of this process by examining behavioral trajectories of audiovisual associative learning in 110 7- to 12-year-old children with and without dyslexia. Children were asked to learn the associations between eight novel symbols and native speech sounds in a brief training and subsequently read words and pseudowords written in the artificial orthography. We then investigated the influence of auditory attention as one of the putative domain-general factors influencing associative learning. To this aim, we assessed children with experimental measures of auditory sustained selective attention and interference control. Our results showed shallower learning trajectories in children with dyslexia, especially during the later phases of the training blocks. Despite this, children with dyslexia performed similarly to typical readers on the post-training reading tests using the artificial orthography. Better auditory sustained selective attention and interference control skills predicted greater response accuracy during training. Sustained selective attention was also associated with the ability to apply these novel correspondences in the reading tests. Although this result has the limitations of a correlational design, it denotes that poor attentional skills may constitute a risk during the early stages of reading acquisition, when children start to learn letter-speech sound associations. Importantly, our findings underscore the importance of examining dynamics of learning in reading acquisition as well as individual differences in more domain-general attentional factors.

What Factors Contribute to Reading in ADHD: Examining Reading-Related Skills in Children With ADHD Only/Comorbid Developmental Dyslexia

BACKGROUND

ADHD and developmental dyslexia (DD) frequently co-occur. However, it is unclear why some children with ADHD acquire DD while others do not.

METHODS

A total of 830 children (including typically developing controls, ADHD only, DD only, and ADHD + DD groups) of two ages (younger: first-third grade; older: fourth-sixth grade) were assessed on measures of reading ability and reading-related skills.

RESULTS

The clinical groups had different degrees of impairment in each reading-related skill. Regression results found that the four groups had different skills in predicting reading ability in younger and older grades. Especially, rapid automatized naming (RAN) was the only predictor of reading ability in children with ADHD only.

CONCLUSIONS

The study highlights that RAN plays an important role in the reading development of children with ADHD only, reflecting the possible protective role of RAN in reading development.

Left-dominance for resting-state temporal low-gamma power in children with impaired word-decoding and without comorbid ADHD

One theory of the origins of reading disorders (i.e., dyslexia) is a language network which cannot effectively 'entrain' to speech, with cascading effects on the development of phonological skills. Low-gamma (low-γ, 30-45 Hz) neural activity, particularly in the left hemisphere, is thought to correspond to tracking at phonemic rates in speech. The main goals of the current study were to investigate temporal low-γ band-power during rest in a sample of children and adolescents with and without reading disorder (RD). Using a Bayesian statistical approach to analyze the power spectral density of EEG data, we examined whether (1) resting-state temporal low-γ power was attenuated in the left temporal region in RD; (2) low-γ power covaried with individual reading performance; (3) low-γ temporal lateralization was atypical in RD. Contrary to our expectations, results did not support the hypothesized effects of RD status and poor decoding ability on left hemisphere low-γ power or lateralization: post-hoc tests revealed that the lack of atypicality in the RD group was not due to the inclusion of those with comorbid attentional deficits. However, post-hoc tests also revealed a specific left-dominance for low-γ rhythms in children with reading deficits only, when participants with comorbid attentional deficits were excluded. We also observed an inverse relationship between decoding and left-lateralization in the controls, such that those with better decoding skills were less likely to show left-lateralization. We discuss these unexpected findings in the context of prior theoretical frameworks on temporal sampling. These results may reflect the importance of real-time language processing to evoke gamma rhythms in the phonemic range during childhood and adolescence.

Disco interacting protein 2 homolog A (DIP2A): A key component in the regulation of brain disorders

Disco Interacting Protein 2 Homolog A (DIP2A) is expressed throughout the body and abundantly expressed in the brain tissue. It is activated by Follistatin-like 1 (FSTL1). Activated DIP2A interacts with several pathways, such as AMPK/mTOR and AKT pathways, to contribute to many biological processes, such as oxidative stress, transcriptional regulation, and apoptosis. Dysregulated DIP2A activation has been implicated in numerous processes in the brain. If the upstream pathways of DIP2A remain globally unexplored, many proteins, including cortactin, AMPK, and AKT, have been identified as its downstream targets in the literature. Recent studies have linked DIP2A to a variety of mechanisms in many types of brain disorders, suggesting that regulation of DIP2A could provide novel diagnostic and therapeutic approaches for brain disorders. In this review, we comprehensively summarized and discussed the current research on DIP2A in various brain disorders, such as stroke, autism spectrum disorders (ASD), Alzheimer's disease (AD), dyslexia, and glioma.

Rapid Online Assessment of Reading (ROAR): Evaluation of an Online Tool for Screening Reading Skills in a Developmental-Behavioral Pediatrics Clinic

OBJECTIVE

Reading difficulties are highly prevalent and frequently co-occur with other neurodevelopmental/behavioral conditions. It is difficult to assess reading routinely in pediatric clinical practice because of time and resource constraints. Rapid Online Assessment of Reading (ROAR) is an objective, gamified assessment that children take in a web browser without adult supervision. This study's purpose was to evaluate ROAR as a screening tool for reading difficulties in a clinical setting.

METHOD

A convenience sample of 6- to 14-year-old children, attending an in-person or telehealth visit in a developmental-behavioral pediatrics (DBP) clinic participated. Children took ROAR and completed the Woodcock-Johnson IV Letter-Word Identification (LWID) and Word Attack (WA). Basic Reading Skills (BRS), a standardized aggregate score of LWID and WA, was used as the gold-standard assessment. The strength of association between standard scores on ROAR and BRS was calculated. BRS scores < 90 (bottom quartile) were classified as poor readers. Receiver operating characteristic (ROC) curve analysis was used to assess the quality of ROAR as a screening test.

RESULTS

A sample of 41 children, 78% boys, mean age 9.5 years (SD 2.0 years), completed the study. The correlation of ROAR standard score with BRS was r = 0.66, p < 0.001. ROC curve analysis with ROAR scores accurately classified poor readers with an area under the curve (AUC) of 0.90.

CONCLUSION

ROAR is a useful objective screening tool to identify children at high risk for reading difficulties. Assessment of the tool during a busy clinic was challenging, and a larger replication is warranted.

Attention-deficit/hyperactive-impulsive disorder symptoms among grade 1 students with reading disorder in Thailand

BACKGROUND

Reading disorder is the most common comorbid condition with attention-deficit/hyperactive-impulsive disorder (ADHD) in school-aged children.

PURPOSE

This study compared symptoms of ADHD among children in grade 1 at risk of reading disorder with children not at risk.

METHODS

This cross-sectional study included 703 students in grade 1 aged 6-8 years from 8 schools in Pathumthani Province, Thailand, in 2019. Reading disorder was assessed using tools developed by Vibulpatanavong and Evans for Thai teachers, whereas the Thai parent and teacher versions of the Swanson, Nolan, and Pelham IV Rating Scale (SNAP-IV) was used to evaluate ADHD symptoms. Demographic data were collected from parents using a self-reported questionnaire.

RESULTS

Among the 703 students with almost equal number of male (n=350) and female (n=353), and the average age of 6.56±0.57 years, 95 (13.51%) were classified (significantly male) at risk of reading disorder. The mean SNAP-IV scores of children with reading disorder reported by parents and teachers (20.23±10.95 and 20.75±15.08, respectively) were significantly higher than those of neurotypical children (16.04 ±8.59 and 9.00±10.14, respectively, P<0.05). Of the 95 students with reading disorder reported by parents and teachers, 29 (30.53%) and 20 (21.05%) respectively, were defined as having ADHD according to the standard cutoff SNAP-IV scores, which were significantly higher than 608 neurotypical students at 108 (17.76%) and 20 (5.59%) (P<0.05). The odds ratios of children with reading disorder having ADHD symptoms according to teacher reports were 3.32 (95% confidence interval [CI], 1.14-9.67; P<0.05), 3.75 (95% CI, 1.60-8.79; P<0.05), and 4.41 (95% CI, 1.20-16.15; P<0.05) for inattentive, hyperactive, and combined presentations, respectively.

CONCLUSION

Grade 1 students with reading disorder had a significantly higher prevalence of ADHD symptoms than neurotypical students. Therefore, children with reading disorders should undergo ADHD assessments and receive proactive intervention.

Home reading environment, sociometric and demographic factors associated with dyslexia in primary school students in China: A case-control study

Background

Developmental dyslexia (DD) has been generally recognized as a multifactorial psychological disorder in recent decades. However, studies on reading and learning environment, social and demographic factors affecting Chinese developmental dyslexia (DD) are still scarce in China. This study aims to explore multidimensional home influencing factors associated with DD before and after birth.

Methods

A total of 60 dyslexic and 252 normal elementary school students graded 2-5 were recruited in Shantou, China. The Least Absolute Shrinkage and Selection Operator (LASSO) regression model was used for the social and demographic variables screening. Odds ratios (ORs) with 95 % confidence intervals (CIs) for associations between DD and related factors were estimated by multivariate logistic regression models.

Results

Through LASSO regression, we ultimately identified 13 key variables, including maternal education level and family monthly income, among others. The logistic regression analyses showed that the risk of DD was higher in children with lower maternal education levels. Divergent parenting styles may be a risk factor for developing DD as opposed to consistent parenting styles (OR = 4.93, 95%CI: 1.11-21.91). Children whose mothers suffered from malnutrition during pregnancy were more likely to develop DD (OR = 10.31, 95%CI: 1.84-37.86), as well as exposure to second-hand smoking at home every day (OR = 5.33, 95%CI: 1.52-18.66). Interestingly, children's active reading (OR = 0.26, 95%CI: 0.08-0.84; OR = 0.17, 95%CI: 0.04-0.76 for "sometimes" and "often" compared to none, respectively), children having extracurricular reading fairy tale books (OR = 0.37, 95%CI: 0.15-0.90), and children having extracurricular reading composition books (OR = 0.25, 95%CI: 0.09-0.69) were significant protective factors for DD.

Conclusions

Home reading environment, several educational, sociometric and demographic factors may influence the development of dyslexia. We should pay attention to these factors on the development of dyslexia, so as to provide the well social and familial environment to ensure the healthy development of children.

Disentangling dyslexia from typical L2-learning in emergent literacy

The present paper assessed how dyslexia can be identified in school children with another language than their first language. Participants were school children with Norwegian as their second language (L2), and two groups of children with Norwegian as their first language (L1): a control group (L1-Con), and a dyslexia group (L1-Dys). All were 2nd and 3rd graders who had attended Norwegian schools from 1st grade on. None of the individuals in L1-Con or the L2 group were identified with any learning disability. However, slow literacy progress was seen in some L2-children. The children were tested individually within the symptomatic and cognitive levels. Results were analysed in two steps: (1) group comparisons; (2) L2 individual profiles and tentative L2 subgrouping. An unexpected L2 profile showed language scores below norm, coupled with some scores within and some scores above norm within the cognitive domain. Case assessment of the L2 group resulted in three subgroups: one comparable to L1-Con, one comparable to L1-Dys, and one with a result in between these two groups. Low linguistic scores cannot be considered valid markers of dyslexia in L2. Within the cognitive domain, a variety of low scores can indicate dyslexia, while high scores can be compensatory.

The Role of Environmental Chemicals in the Etiology of Learning Difficulties: A Novel Theoretical Framework

Children from economically disadvantaged communities have a disproportionate risk of exposure to chemicals, social stress, and learning difficulties. Although animal models and epidemiologic studies link exposures and neurodevelopment, little focus has been paid to academic outcomes in environmental health studies. Similarly, in the educational literature, environmental chemical exposures are overlooked as potential etiologic factors in learning difficulties. We propose a theoretical framework for the etiology of learning difficulties that focuses on these understudied exogenous factors. We discuss findings from animal models and longitudinal, prospective birth cohort studies that support this theoretical framework. Studies reviewed point to the effects of prenatal exposure to polycyclic aromatic hydrocarbons on reading comprehension and math skills via effects on inhibitory control processes. Long term, this work will help close the achievement gap in the United States by identifying behavioral and neural pathways from prenatal exposures to learning difficulties in children from economically disadvantaged families.

Heterogeneity of short-term memory deficits in children with dyslexia

Many studies have highlighted short-term memory (STM) impairment in dyslexic individuals. Several studies showed deficits for both item and serial order aspects of verbal STM in dyslexic individuals. These group-based studies, however, do not inform us about the prevalence of these deficits and, importantly, their potential heterogeneity at the individual level. The present study examined both group-level and individual STM profiles in dyslexic and age-matched non-dyslexic children. While confirming previous group-based results of both item and serial order STM deficits, individual analyses indicated two distinct profiles: one profile was associated with verbal item STM and phonological impairment while another profile showed selective serial STM deficits in both verbal and visual domains. Our results highlight the need for practitioners to consider the heterogeneous nature of STM impairment in dyslexia and to adapt STM and reading treatment strategies accordingly.

Dyslexia and Stuttering: An Overview of Processing Deficits and the Relationship Between Them

Stuttering and dyslexia are two processing deficits that have an impact on a person's social and academic lives, especially as they usually affect the pediatric population more than adults. Even though they affect different domains, they have similar characteristics in their pathogenesis, epidemiology, and impact on life. Both disorders represent a considerable percentage of the population worldwide and locally in Saudi Arabia, and they have similar epidemiological trends. Family history, genetic factors, early fetal and neonatal factors, and environmental factors are all identified as risk factors for both conditions. Moreover, it has been established that both diseases share a common genetic and anatomical basis, along with a mutual disruption of diadochokinetic skills. While rehabilitative techniques can be used in both conditions, stuttering could also benefit from pharmacological interventions. This review emphasizes that extensive research should be done to explore both of these conditions as they impact different areas of one's life and the relationship between them to better understand their pathophysiological origins.

Visual attention span deficit in developmental dyslexia: A meta-analysis

BACKGROUND

Visual attention span (VAS) refers to the number of visual elements processed simultaneously in a multielement array. Yet, there are mixed findings regarding VAS deficit in developmental dyslexia (DD) across different tasks, stimuli, languages, control groups, and ages.

AIM

The present meta-analysis aimed to investigate VAS deficit in DD and factors moderating VAS deficit in DD.

METHODS

A meta-analysis based on 32 articles, 54 independent studies, and 4211 subjects was conducted. Effect sizes for each study were calculated and a random-effect model was selected. Task and stimulus types in the VAS task, writing system, orthographic depth, control group type, and age were included as possible moderators.

RESULTS

1) VAS in dyslexic individuals was significantly worse than typically developing individuals; 2) Task-stimulus type (report-verbal/n-back-verbal/n-back-nonverbal), writing system (alphabetic vs. Chinese), and control group type (age matched vs. reading matched) significantly moderated VAS deficit in DD. VAS deficit was more severe in report task with verbal stimuli than in n-back task with verbal and nonverbal stimuli. VAS deficit was more severe in alphabetic language than in Chinese. VAS deficit was more severe when compared with age-matched controls than compared with reading-matched controls.

CONCLUSION

VAS deficit is a possible etiology for DD and moderated by task-stimulus type, writing system, and control group type. These findings have important implications for the understanding of DD.

The ReadFree tool for the identification of poor readers: a validation study based on a machine learning approach in monolingual and minority-language children

In this study, we validated the "ReadFree tool", a computerised battery of 12 visual and auditory tasks developed to identify poor readers also in minority-language children (MLC). We tested the task-specific discriminant power on 142 Italian-monolingual participants (8-13 years old) divided into monolingual poor readers (N = 37) and good readers (N = 105) according to standardised Italian reading tests. The performances at the discriminant tasks of the "ReadFree tool" were entered into a classification and regression tree (CART) model to identify monolingual poor and good readers. The set of classification rules extracted from the CART model were applied to the MLC's performance and the ensuing classification was compared to the one based on standardised Italian reading tests. According to the CART model, auditory go-no/go (regular), RAN and Entrainment100bpm were the most discriminant tasks. When compared with the clinical classification, the CART model accuracy was 86% for the monolinguals and 76% for the MLC. Executive functions and timing skills turned out to have a relevant role in reading. Results of the CART model on MLC support the idea that ad hoc standardised tasks that go beyond reading are needed.

Associative gene networks reveal novel candidates important for ADHD and dyslexia comorbidity

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is commonly associated with developmental dyslexia (DD), which are both prevalent and complicated pediatric neurodevelopmental disorders that have a significant influence on children's learning and development. Clinically, the comorbidity incidence of DD and ADHD is between 25 and 48%. Children with DD and ADHD may have more severe cognitive deficiencies, a poorer level of schooling, and a higher risk of social and emotional management disorders. Furthermore, patients with this comorbidity are frequently treated for a single condition in clinical settings, and the therapeutic outcome is poor. The development of effective treatment approaches against these diseases is complicated by their comorbidity features. This is often a major problem in diagnosis and treatment. In this study, we developed bioinformatical methodology for the analysis of the comorbidity of these two diseases. As such, the search for candidate genes related to the comorbid conditions of ADHD and DD can help in elucidating the molecular mechanisms underlying the comorbid condition, and can also be useful for genotyping and identifying new drug targets.

RESULTS

Using the ANDSystem tool, the reconstruction and analysis of gene networks associated with ADHD and dyslexia was carried out. The gene network of ADHD included 599 genes/proteins and 148,978 interactions, while that of dyslexia included 167 genes/proteins and 27,083 interactions. When the ANDSystem and GeneCards data were combined, a total of 213 genes/proteins for ADHD and dyslexia were found. An approach for ranking genes implicated in the comorbid condition of the two diseases was proposed. The approach is based on ten criteria for ranking genes by their importance, including relevance scores of association between disease and genes, standard methods of gene prioritization, as well as original criteria that take into account the characteristics of an associative gene network and the presence of known polymorphisms in the analyzed genes. Among the top 20 genes with the highest priority DRD2, DRD4, CNTNAP2 and GRIN2B are mentioned in the literature as directly linked with the comorbidity of ADHD and dyslexia. According to the proposed approach, the genes OPRM1, CHRNA4 and SNCA had the highest priority in the development of comorbidity of these two diseases. Additionally, it was revealed that the most relevant genes are involved in biological processes related to signal transduction, positive regulation of transcription from RNA polymerase II promoters, chemical synaptic transmission, response to drugs, ion transmembrane transport, nervous system development, cell adhesion, and neuron migration.

CONCLUSIONS

The application of methods of reconstruction and analysis of gene networks is a powerful tool for studying the molecular mechanisms of comorbid conditions. The method put forth to rank genes by their importance for the comorbid condition of ADHD and dyslexia was employed to predict genes that play key roles in the development of the comorbid condition. The results can be utilized to plan experiments for the identification of novel candidate genes and search for novel pharmacological targets.