Phonological working memory and central executive function differ in children with typical development and dyslexia

Improving cognitive function in Chinese children with ADHD and/or RD through computerized working memory training

BACKGROUND

Prior research has found that children with attention-deficit hyperactivity disorder (ADHD) and reading difficulties (RD) are at an elevated risk of developing further cognitive deficits and developmental challenges [1]. ADHD and RD are characterized by a deficit in working memory, which negatively affects learning and behavior. The main aims of this study were to design a working memory training app and examine its effectiveness through a 5-week training program in Chinese children with ADHD and/or RD.

METHODS

There were three experimental groups, with 26 participants in the ADHD group, 38 participants in the RD group, and 24 participants in the ADHD + RD group. The typically developing (TD) control group had 32 participants. All participants completed the pretest and posttest assessments on executive function and reading performance.

RESULTS

The findings indicate that the experimental groups improved performance in verbal and visual-spatial working memory as well as Chinese word reading. There was an overall reduction in functional impairment following the training, in contrast to the TD group.

CONCLUSION

This study showed that working memory can be improved through computerized training in children with ADHD and/or RD. The implications of future research in working memory are discussed.

TRIAL REGISTRATION

Clinical Trials Identifier: NCT06567444 (retrospectively registered) on 20 August 2024.

Neurocognitive mechanisms of co-occurring math difficulties in dyslexia: Differences in executive function and visuospatial processing

Children with dyslexia frequently also struggle with math. However, studies of reading disability (RD) rarely assess math skill, and the neurocognitive mechanisms underlying co-occurring reading and math disability (RD+MD) are not clear. The current study aimed to identify behavioral and neurocognitive factors associated with co-occurring MD among 86 children with RD. Within this sample, 43% had co-occurring RD+MD and 22% demonstrated a possible vulnerability in math, while 35% had no math difficulties (RD-Only). We investigated whether RD-Only and RD+MD students differed behaviorally in their phonological awareness, reading skills, or executive functions, as well as in the brain mechanisms underlying word reading and visuospatial working memory using functional magnetic resonance imaging (fMRI). The RD+MD group did not differ from RD-Only on behavioral or brain measures of phonological awareness related to speech or print. However, the RD+MD group demonstrated significantly worse working memory and processing speed performance than the RD-Only group. The RD+MD group also exhibited reduced brain activations for visuospatial working memory relative to RD-Only. Exploratory brain-behavior correlations along a broad spectrum of math ability revealed that stronger math skills were associated with greater activation in bilateral visual cortex. These converging neuro-behavioral findings suggest that poor executive functions in general, including differences in visuospatial working memory, are specifically associated with co-occurring MD in the context of RD. RESEARCH HIGHLIGHTS: Children with reading disabilities (RD) frequently have a co-occurring math disability (MD), but the mechanisms behind this high comorbidity are not well understood. We examined differences in phonological awareness, reading skills, and executive function between children with RD only versus co-occurring RD+MD using behavioral and fMRI measures. Children with RD only versus RD+MD did not differ in their phonological processing, either behaviorally or in the brain. RD+MD was associated with additional behavioral difficulties in working memory, and reduced visual cortex activation during a visuospatial working memory task.

Associations between Executive Functions and Sensorimotor Performance in Children at Risk for Learning Disabilities

Executive functions (EF) and sensorimotor skills play a critical role in children's goal-directed behavior and school readiness. The aim of the current study is to provide new insights into the relationship between executive functions and sensorimotor development by considering the risks associated with learning difficulties. Therefore, we investigate the predictive role of EF and sensorimotor skills in the development of learning difficulties during preschool years. Ninety-five preschool children (5-7 years old) were tested, comparing the performance of children that are at risk of learning difficulties (n = 55) to the performance of typically developing children (n = 40). Participants completed a battery for the assessment of sensorimotor skills (i.e., Southern California Sensory Integration Test: postural imitation, body midline crossing, bilateral motor coordination, and standing balance with eyes open) and executive functions (i.e., inhibition, cognitive flexibility, and verbal working memory). Our results show that children at risk for learning difficulties exhibited more impairments on sensorimotor and EF measures (inhibition and verbal working memory) when compared with TD children. We ran three separate binary logistic regression analyses to assess the relative influence of EF and sensorimotor functions on predicting risk for learning difficulties. Our findings demonstrated that verbal working memory as EF function (odd ratio (OR) = 0.91, 95% CI 0.78-0.91, P = 0.05) and standing balance skills as a sensorimotor skill (odd ratio (OR) = 0.86, 95% CI 0.81-0.98, P = 0.01) were the strongest predictors of risk for learning difficulties. The findings point to the importance of supporting children's executive function development and promoting sensorimotor development, as both fundamentally influence school readiness.

Working memory capacity and text comprehension performance in children with dyslexia and dyscalculia: a pilot study

Introduction

Different research over the years has shown how the executive processes of Working Memory are a fundamental area that allows the performance of complex cognitive tasks such as language comprehension, reading, mathematical skills, learning or reasoning. Therefore, scientific evidence shows that they are altered in people with dyslexia and dyscalculia. The aim of this research was to study the relationship between semantic updating ability and reading comprehension depending on whether or not the information content had a mathematical character between the two disorders.

Methods

A Pilot Case Study was carried out for this purpose. The sample consisted of 40 participants aged 6 to 11 years, 20 of them with a diagnosis of dyslexia and the remaining 20 with a diagnosis of dyscalculia. The results indicate that people with dyslexia show more difficulties in all those tasks that require reading.

Results

People with dyscalculia obtain worse results in the tasks of stimulus integration and reading comprehension of texts with mathematical content. Furthermore, the correlation between the different areas evaluated shows that people with dyslexia and dyscalculia develop different cognitive processes.

Discussion

Therefore, it is necessary to continue insisting on the importance of explicit work on working memory, since it is a determining and fundamental area in the development of written language comprehension.

Colour-cued paragraph writing instruction for students with learning disabilities

Expository paragraph writing is difficult to learn and teach. For many students, particularly those with learning disabilities, it is difficult to manage the multiple, simultaneous complex processes required for success. And for their teachers, writing is the content area in which they feel least prepared to teach. This intervention applied the concept of reverse engineering to instructional design to teach expository paragraph writing using a color-cued graphic organizer. The study evaluated the effects of using a systematic color code to highlight the alignment of where ideas originate in a graphic organizer to their development into a sentence within a well-organized expository paragraph. Using a single case research design, with a pre- and post-intervention assessments, students (n = 5) with dyslexia improved their expository paragraph knowledge and skills. Percentage of non-overlapping data and Tau analyses indicate a large to very large effect of the 2-week intervention. Results, suggestions for further research, and implications for practice are discussed.

Working Memory and Manual Dexterity in Dyslexic Children: A Systematic Review and Meta-Analysis

Dyslexic children have impairments in working memory and manual dexterity. Studies have shown that when cognitive development has deficits, motor development is often impaired, indicating a strong interconnection between both domains, and the possibility of interference with each other's proper functioning. Thus, a new literature review is necessary to understand which components of working memory and manual dexterity are affected in dyslexic children and the possible relationship between them. This review aimed to perform a systematic review and meta-analysis to analyze both skills in dyslexic children. The protocol was carried out according to the criteria established by PRISMA being registered at PROSPERO under number CRD 42021238901. Six literature databases were searched to locate studies published between 2001 and 2021: EMBASE, ERIC, ISI Web of Science, PubMed, PsycINFO, and Scopus. 21 studies met the inclusion criteria. The findings suggest that dyslexic children have significantly poorer visuospatial and verbal working memory with more impairments in the phonological loop. No significant differences were found in manual dexterity.

The P300 event related potential predicts phonological working memory skills in school-aged children

The P300 event related potential (ERP) has been cited as a marker of phonological working memory (PWM); however, little is known regarding its relationship to behavioral PWM skills in early school-aged children. The current study investigates the P300 ERP recorded in response to native and non-native (English and Spanish) phoneme contrasts as a predictor of PWM skills in monolingual English-speaking first and second grade children. Thirty-three typically developing children, ages 6–9, completed a battery of phonological processing, language, and cognitive assessments. ERPs were recorded within an auditory oddball paradigm in response to both English phoneme contrasts (/ta/, /pa/) and Spanish contrasts (/t̪a/, /d̪a/). The P300 ERP recorded in response to English phoneme contrasts significantly predicted standard scores on the Nonword Repetition subtest of the Comprehensive Test of Phonological Processing, Second Edition. Spanish contrasts did not elicit a P300 response, nor were amplitude or latency values within the P300 timeframe (250–500 ms) recorded in response to Spanish contrasts related to English nonword repetition performance. This study provides further evidence that the P300 ERP in response to native phonemic contrasts indexes PWM skills, specifically nonword repetition performance, in monolingual children. Further work is necessary to determine the extent to which the P300 response to changing phonological stimuli reflects PWM skills in other populations.