Combining transcranial direct current stimulation with a rhythm-based intervention to improve reading fluency in young adults with dyslexia.

Childhood dyslexia risk elevated by heavy metal mixtures from e-waste: A machine learning-driven mixture modeling study.

To determine whether individuals with developmental dyslexia present differences in visual and oculomotor functions compared with age-matched controls. Developmental dyslexia affects a substantial proportion of school-aged children, with prevalence estimates ranging between 3% and 6%, depending on diagnostic criteria. It is characterised by persistent reading difficulties despite normal intelligence and education. Although phonological deficits are well established, the contribution of visual and oculomotor anomalies remains debated. Identifying consistent visual differences may support more comprehensive assessments and targeted interventions alongside educational strategies. This systematic review and meta-analysis, registered in PROSPERO (CRD420251119429), included observational case-control studies comparing visual and oculomotor functions in individuals with developmental dyslexia and age-matched controls. Searches were conducted in PubMed, Web of Science, and Scopus. Outcomes included binocular vision, oculomotor performance, accommodation, visual acuity, refractive error and contrast sensitivity. Methodological quality was assessed using the MINORS tool and certainty of evidence using GRADE. Twenty-six studies with 8 to 124 participants per group were included. Dyslexic individuals showed significantly greater near exophoria (mean difference 0.84 prism diopters, 95% CI: 0.22 to 1.46) and reduced near fusional vergence ranges, including negative (-6.42 prism diopters, 95% CI: -8.65 to -4.19) and positive fusional vergence (-6.72 prism diopters, 95% CI: -8.66 to -4.77), all p < 0.01. Oculomotor differences included a higher number of fixations, longer fixation duration, more regressions and reduced saccade amplitude. No significant group differences were found for refractive error or visual acuity. Children with developmental dyslexia exhibit consistent binocular and oculomotor anomalies that may increase visual effort during reading. Incorporating targeted assessment of these functions into vision care may complement multidisciplinary management. Further research is needed to clarify their clinical relevance.

Neuroimaging meta-analyses of phonological awareness deficits in children with developmental dyslexia.

Evaluation of central auditory processing in children with developmental dyslexia.

Resolving the mystery of Chinese developmental dyslexia: in search of predictors and early markers.

In the present study, 43 Italian school-age children (age range = 7-14 years, 16 females) with (N = 19) and without DD (N = 24) were presented with pairs of visual displays separated by varying interstimulus intervals and performed either a temporal integration or segregation task despite an identical visual input. Children with DD had lower accuracy and slower RTs for longer temporal intervals. Additionally, efficiency (combined accuracy and speed trade-off) increased as a function of age only in the DD group, most markedly for the integration condition. Results suggest that visual temporal processing deficits in DD may depend on short-term/working memory liability as well as the existence of possibly differentiated developmental trajectories for integration and segregation abilities.

One of the most important theories proposed in the explanation and etiology of dyslexia are theories that consider the cognitive deficits of these children, including attention, working memory, planning and organization to be involved in the occurrence of this disability. The aim was to investigate the effects of combining sensory integrative techniques with direct reading comprehension on improving working memory and attention span in students with Developmental dyslexia. This randomized trial with blinded assessors study was performed with a between-subjects factor 'group' (control group vs. intervention group) and within-subjects factor 'time' (measurement at pre-intervention and post-intervention). Data collection started in February 2024 and ended in October 2024. Sixty children with Developmental dyslexia were recruited to the study following formal diagnostic and behavioral pre-intervention assessments. Continuous Performance Test (CPT) and The Arabic Wechsler Intelligence Scale for Children - Fourth Edition (WISC-IV) were used to collect data. Linear regression models were used to assess within-person differences within conditions for each outcome. Findings did directly support the hypotheses; results from regression analyses suggest that sensory integrative techniques with direct reading comprehension did have a significant impact on working memory and attention span in students with Developmental dyslexia. Sensory integration method and direct instruction for comprehension can increase working memory and attention span in children with dyslexia.

Correction to: How do children with developmental dyslexia in Chinese integrate sentence–picture information?

ABSTRACT Purpose Empirical support for the sluggish attentional shifting theory of developmental dyslexia (DD) remains debated. Inconsistent findings have been attributed to divergent paradigms for assessing attentional orienting, variability in participant ages, and cross-linguistic differences in script-processing demands. Therefore, the present study systematically investigated exogenous and endogenous attentional orienting in Chinese children with dyslexia across high and low grades of primary schools. Methods A total of Eighty-eight Mandarin-speaking children (46% female, M age = 9.38) participated, including 44 children with DD and 44 age-matched typically developing (TD) children. Participants were divided into two grade-based groups: a low-grade group (Grades 2–3, n = 46, DD/TD = 23/23, 48% female, M age = 8.73) and a high-grade group (Grades 4–5, n = 42, DD/TD = 21/21, 43% female, M age = 10.09). All children completed reading-related assessments and exogenous/endogenous spatial cueing tasks. Results In the low-grade group, children with dyslexia showed longer reaction times and a smaller right-hemifield cueing effect in the exogenous attention task compared with their TD peers, indicating deficits in both attentional orienting and right-hemifield inhibition, which linked to poor sentence reading and orthographic awareness. These exogenous orienting deficits were attenuated in the high-grade group. Moreover, endogenous attentional orienting was generally intact in the current cohort of children with dyslexia and was associated with sentence-reading performance specifically in the high grades. Conclusion These results indicate that the exogenous attentional orienting deficit may be an early marker for DD identification while preserved endogenous attention orienting may compensate in children with dyslexia from high grades. The findings support the sluggish attentional shift theory from a developmental aspect and emphasize the importance of considering language-specific and age-related factors in characterizing dyslexia.

Objective This study aimed to develop and evaluate the psychometric properties of the Azeri Non-word repetition test (ANWRT) for Azeri–Persian bilingual children aged 7–12 years in Iran. Methods In this cross-sectional study, 300 children (240 typically developing and 60 with developmental dyslexia (DD)) participated. The ANWRT consists of 20-words across four syllable lengths (1–4 syllables), constructed according to Azeri phonotactics. Face and content validity were confirmed by experts and child feedback. Construct validity was assessed by group comparison, criterion validity by correlation with forward digit span, and diagnostic accuracy using ROC analysis. Reliability was examined through test–retest and internal consistency. Results Children with DD scored significantly lower than typically developing peers (p < .001). Criterion validity was supported by a significant correlation with forward digit span in the DD group (r = 0.287, p = .028). The test showed strong diagnostic accuracy (AUC 0.621–0.850) with optimal cutoffs (11.5 for Grades 1–2; 14.5 for Grades 3–6). Reliability was excellent (test–retest ICC = 0.93; Kuder–Richardson = 0.857; McDonald’s ω = 0.837). Conclusion The ANWRT is a reliable and valid tool for assessing phonological short-term memory in Azeri-speaking children and effectively discriminates developmental dyslexia, offering a culturally appropriate instrument for bilingual populations.

While underlying neural changes have been identified in terms of stimulus- and task-related responses within specific brain regions and their neural connectivity, there is still limited understanding of how these changes affect the overall organization of brain networks. This study used EEG and functional network analysis, focusing on small-world propensity across various frequency bands (from δ to γ), to explore the global brain organization during the auditory discrimination of words and pseudowords in children with DD. The main finding revealed a systemic inefficiency in the functional network of individuals with DD, which did not achieve the optimal small-world propensity. This inefficiency arises from a fundamental trade-off between localized specialization and global communication. During word listening, the δ-/γ1-networks (related to impaired syllabic and phonemic processing of words) and the θ-/β-networks (related to pseudoword listening) in the DD group showed lower local clustering and connectivity compared to the control group, resulting in reduced functional segregation. In particular, the θ-/β-networks for words in the DD group exhibited a less optimal balance between specialized local processing and effective global communication. Centralized midline hubs, such as the postcentral gyrus (PstCG) and inferior frontal gyrus (IFG), which are crucial for global coordination, attention, and executive control, were either absent or inconsistent in individuals with DD. Consequently, the DD network adopted a constrained, motor-compensatory, and left-lateralized strategy. This led to the redirection of information flow and processing effort toward the left PstCG/IFG loop, interpreted as a compensatory effort to counteract automatic processing failures. Additionally, the γ1-network, which is involved in phonetic feature binding, lacked engagement from posterior sensory hubs, forcing this critical process into a slow and effortful motor loop. The γ2-network exhibited unusual activation of right-hemisphere posterior areas during word processing, while it employed a simpler, less mature routing strategy for pseudoword listening, which further diminished global communication. This functionality highlights the core phonological and temporal processing deficits characteristic of dyslexia.

Linguistic correlates of Chinese children with developmental dyslexia: a systematic review.

The aim of this study was to examine the neural and behavioral correlates of visual statistical learning in adults with and without developmental dyslexia (DD), using a predictor-target paradigm. Reaction times (RTs) and event-related potentials (ERPs) were used to assess participants' sensitivity to predictor-target contingencies that varied throughout the task. English-speaking neurotypical adults (N=36) and those with DD (N=16) were engaged in a visual statistical learning task while RTs and ERPs were measured. In Phase 1, participants' sensitivity to the contingencies was assessed, in which one stimulus was highly predictive of the target (90% transitional probability) and another was less predictive of the target (10% transitional probability). In Phase 2, these contingencies switched to equal probability (50/50), to assess participants' ability to adapt to the change in stimulus predictability. In Phase 1, both groups showed behavioral evidence of learning the contingencies but only the neurotypical group showed ERP effects indicative of learning. In Phase 2, both groups showed similar ERPs and RTs, indicating that sensitivity to the contingencies from Phase 1 persisted into Phase 2 across groups despite the contingencies being changed. Similar to previous work on children with DD (Singh, Walk, & Conway, 2018), adults with DD showed atypical neural responses but intact motor learning of the visual statistical patterns. These findings suggest that adults with DD may rely on different prediction-based learning mechanisms to acquire visual statistical contingencies, consistent with theories positing differences in visual-attention and basal ganglia-based learning in DD.

In the present study, we examined the differential contribution of semantic knowledge-specifically taxonomic and thematic-to narrative text comprehension in children with developmental dyslexia (DD) aged 8-10 years. Taxonomic knowledge refers to stimuli that are ontologically and logically related, hierarchically organised, linguistically encoded and independent of spatial or temporal links (e.g., the superordinate category animal with members such as lion, dog, or eagle). In contrast, thematic organisation involves stimuli that are related through contextual associations (e.g., meat, knife and fork). Sixty-two children with DD and a control group completed a fluid intelligence test, a semantic working memory task and a narrative text comprehension task. The results showed that taxonomic knowledge was associated with text comprehension only in the control group. Conversely, in the DD group, thematic knowledge predominantly supported comprehension. Overall, these findings contribute to a more detailed understanding of the cognitive and learning profile of children with DD and align with recent research on the relationship between semantic representations, linguistic knowledge and reading comprehension in learning disorders, beyond word decoding difficulties.

Neurophysiological differentiation of Boder's dyslexia subtypes using harmonised quantitative EEG cross-spectra.

Atypical phonological processing is at the core of developmental dyslexia and is linked to aberrant tracking and analysis of auditory information in the cortex. Despite the importance of these mechanisms for speech processing and linguistic development, oral language comprehension in dyslexia remains largely intact. Recent findings suggest that dyslexia-linked atypical cortical processing patterns reflect both underlying deficits and compensatory strategies. This review synthesizes recent evidence linking atypical cortical tracking of auditory information in dyslexia, language development, and neurocognitive mechanisms of adaptive and resilient speech comprehension. We propose hemispheric rebalancing of linguistic analysis as a key compensatory mechanism in dyslexia, supported by interhemispheric connectivity within the distributed bilateral language network and greater reliance on lexico-semantic features during speech processing.

Developmental dyslexia (DD) affects approximately 10% of individuals, impairing reading ability thus limiting professional fulfilment and psychological wellbeing. DD is associated with both phonological and visual deficits, and the latter are attributed to dysfunctions of the magnocellular-dorsal visual stream, which has a critical role in planning saccades and supporting the extraction of letters/words identity. Currently, there are no effective treatments to restore the brain networks underlying visuospatial analysis and oculomotor efficiency. Adults with DD were enrolled in a randomised clinical trial introducing a non-invasive neuromodulation protocol specifically designed to enhance dorsal stream functionality. We used bi-focal beta-band transcranial alternating current stimulation (tACS) in parietal areas, due to the recognized role of beta oscillation in the dorsal stream functionality. Coupled with a 12-session visuoattentional training, such protocol induced improvements in reading speed, oculomotor control, and visual motion perception. Additionally, beta-tACS led to long-term enhancement of working memory. These outcomes were exclusive or superior to those obtained with a placebo/sham neuromodulation, and were accompanied by plastic changes in the stimulated brain networks. Overall, our findings show the efficacy of multisession tACS in improving core visual, oculomotor and cognitive deficits associated with reading disorders.

Abstract Developmental dyslexia is a specific learning disability characterized by impairments in learning to read and write; however, it impacts more than just school performance. It also impacts self-esteem, self-worth, and overall well-being. Dyslexia has a known genetic component, yet previous literature has not explored the experience of being an adolescent with dyslexia who also has a parent with dyslexia. The current study explored the experiences of adolescents with dyslexia who also had a parent with dyslexia using reflexive thematic analysis to analyze interviews and focus groups with ten adolescents aged 13 to 18. Participants were diagnosed with dyslexia and had a parent who was formally or self-diagnosed with dyslexia. Findings highlight four themes: 1 ) “He would just hold me. And that was the best thing right there , ” (2) “They accept me for who I am , ” (3) “People weren’t doing really much for me…Then I came here , ” and (4) “Perseverance is a word to describe who we are , ” couched within an overarching theme of Resilience. The findings highlight the importance of personal assets and external resources in the resilience of adolescents diagnosed with dyslexia. Specifically, they indicate the need for parental and social support, school-based support, increased education surrounding what is and is not dyslexia, and the importance of healthy coping skills.

Developmental dyslexia is frequently associated with deficits in working memory, visual perception, and attentional processes, which substantially interfere with reading acquisition and academic achievement. In recent years, game based cognitive remediation has emerged as a promising intervention for enhancing cognitive functioning in children with neurodevelopmental disorders. The present study aimed to investigate the effects of a structured game based cognitive remediation program on working memory, neurovisual perception, visuospatial abilities, and visual attention in Moroccan children with developmental dyslexia.Fifteen children diagnosed with developmental dyslexia (mean age = 8.47 0.52 years) participated in a structured program of game based cognitive stimulation. Neuropsychological assessments were conducted before and after the intervention and included the Working Memory Index (WMI; WISC V), the Rey–Osterrieth Complex Figure Test, the Visuospatial Index and Processing Speed Index (VSI; WISC V), and the Bells Test for visual attention. Pre and post intervention performances were compared using Wilcoxon signed rank tests for paired samples.Significant improvements were observed across all assessed cognitive domains. Visual memory increased from 34.8 6.35 to 37.8 7.78 (W = 1.00, p = 0.001). Working memory improved from 89.8 16.39 to 95.1 15.20 (W = 2.00, p = 0.002). Visuospatial abilities and processing speed increased from 78.7 11.20 to 80.3 11.22 (W = 0.00, p = 0.003). Visual attention (Bells Test) improved from 28.7 1.84 to 29.7 1.91 (W = 0.00, p = 0.005).These findings indicate that game based cognitive remediation can effectively enhance working memory, neurovisual perception, visuospatial processing, and attentional control in children with developmental dyslexia. This approach represents a promising and engaging method for improving cognitive functioning and learning outcomes, particularly within the Moroccan educational context.