Working memory functioning in children with learning disabilities: does intelligence make a difference?

Taking a Closer Look: The Relationship between Pre-School Domain General Cognition and School Mathematics Achievement When Controlling for Intelligence

Intelligence, as well as working memory and attention, affect the acquisition of mathematical competencies. This paper aimed to examine the influence of working memory and attention when taking different mathematical skills into account as a function of children’s intellectual ability. Overall, intelligence, working memory, attention and numerical skills were assessed twice in 1868 German pre-school children (t1, t2) and again at 2nd grade (t3). We defined three intellectual ability groups based on the results of intellectual assessment at t1 and t2. Group comparisons revealed significant differences between the three intellectual ability groups. Over time, children with low intellectual ability showed the lowest achievement in domain-general and numerical and mathematical skills compared to children of average intellectual ability. The highest achievement on the aforementioned variables was found for children of high intellectual ability. Additionally, path modelling revealed that, depending on the intellectual ability, different models of varying complexity could be generated. These models differed with regard to the relevance of the predictors (t2) and the future mathematical skills (t3). Causes and conclusions of these findings are discussed.

Diagnostik von Lernstörungen: Zeit zum Umdenken

Zusammenfassung. Lernschwierigkeiten beim Erwerb der Schriftsprache oder des Rechnens gehört für ca. ein Drittel aller Grundschulkinder zum schulischen Alltag. Wenn diese Schwierigkeiten länger andauern, wird von Lernschwächen, Lernstörungen oder Lernbehinderungen gesprochen. Die begriffliche Abgrenzung wird aktuell durch verschiedene Klassifikationskriterien in verschiedenen Klassifikationssystemen (ICD-10/11, DSM-5 oder AWMF Leitlinien) sehr erschwert, was Unsicherheiten in der Diagnostik und auch divergierende pädagogische Konsequenzen zur Folge hat. Eine besondere Rolle spielt dabei das sogenannte doppelte Diskrepanzkriterium für die Diagnose einer Lernstörung: Die Leistung eines Kindes muss unter dem nach dem Alter bzw. der Beschulung und der Intelligenz zu erwartenden Niveau liegen. Die Schulleistung muss also erwartungswidrig ausfallen – das betroffene Kind bleibt hinter den für die Klassenstufe typischen Leistungen und auch hinter den eigenen allgemeinen kognitiven Fähigkeiten zurück. Das Kriterium der Diskrepanz der Schulleistung zur Intelligenz wird seit langem kontrovers diskutiert und ist in den Klassifikationssystemen unterschiedlich verankert. Seine Anwendung hat sowohl für die diagnostische als auch für die pädagogische Praxis weitreichende Konsequenzen. Es führt dazu, dass Kinder mit Diskrepanz zwischen Schulleistung und Intelligenz die Diagnose „Lernstörung“ erhalten, Kinder ohne diese Diskrepanz haben eine „Lernschwäche“, beide Gruppen erfahren unterschiedliche schulische und außerschulische Lernförderung. Der vorliegende Beitrag stellt die Berechtigung dieses Kriteriums der Diskrepanz zwischen Schulleistung und Intelligenz anhand empirischer Evidenz in Frage und beleuchtet Konsequenzen sowohl für die bislang gängige Anwendung des doppelten Diskrepanzkriteriums als auch für den Verzicht darauf. Das Fazit dieser Erörterung rät zum Umdenken.

Executive Functions and Attention Processes in Adolescents and Young Adults with Intellectual Disability

(1) Background: We made a comprehensive evaluation of executive functions (EFs) and attention processes in a group of adolescents and young adults with mild intellectual disability (ID). (2) Methods: 27 adolescents and young adults (14 females and 13 males) with ID, aged between 15.1 and 23 years (M = 17.4; SD = 2.04), were compared to a control group free of cognitive problems and individually matched for gender and age. (3) Results: As for EFs, individuals with ID were severely impaired on all subtests of the Behavioral Assessment of Dysexecutive Syndrome (BADS) battery. However, we also found appreciable individual differences, with eight individuals (approximately 30%) scoring within normal limits. On the attention tests, individuals with ID were not generally slower but presented specific deficits only on some attention tests (i.e., Choice Reaction Times, Color Naming and Color–Word Interference, and Shifting of Attention for Verbal and for Visual Targets).The role of a global factor (i.e., cognitive speed) was modest in contributing to the group differences; i.e., when present, group differences were selectively associated with specific task manipulations, not global differences in cognitive speed. (4) Conclusions: The study confirmed large group differences in EFs; deficits in attentional processing were more specific and occurred primarily in tasks taxing the selective dimension of attention, with performance on intensive tasks almost entirely spared.

Mathematical skills and working memory profile of children with borderline intellectual functioning

Borderline intellectual functioning is a neurodevelopmental condition characterized by an intelligence quotient (IQ) in the range of 70-85. The present study aimed to investigate the mathematical abilities and the working memory of students with borderline intellectual functioning (BIF). The sample group included 10 year-old students with BIF (n = 85) and with average non-verbal IQ (n = 45). The children were assessed in non-verbal intelligence, numerical ability and working memory. Our results showed an impairment of mathematical skills, especially in the operation tasks, and working memory in children with BIF, compared to typically developing peers. Generally, their skills seemed to be consistent with intelligence scores (WOND and AWMA scores ≥ 70). In some cases, children with BIF could have mathematical difficulties (WOND < 70). In general, they showed visuospatial short-term memory and central executive subsystem more damaged than non-verbal intelligence while the verbal short-term memory was similar to the IQ.

Executive Functions and Emotion Regulation in Attention-Deficit/Hyperactivity Disorder and Borderline Intellectual Disability

The main objective of this study is to investigate the multiple relations and to determine the differences between executive functions (EFs), emotion regulation, and behavioral and emotional problems in children with attention-deficit/hyperactivity disorder (ADHD), borderline intellectual disability (ID), and typical development (TD). The sample included 85 children aged 6 to 11 years, 42 with typical development (TD), 27 with ADHD, and 16 with borderline ID. The results emphasized a positive correlation between adaptive emotion regulation strategies and EFs, and no significant relations between the maladaptive emotion regulation strategies and EFs. In addition, the executive function of planning correlated negatively with anxiety, ADHD symptoms, and conduct problems. The performance of both clinical groups regarding EFs was significantly lower than that of the TD group, and they differed significantly from each other only on visual attention. The presence of oppositional-defiant and conduct problems was higher in both clinical groups than in the TD group, and more anxiety symptoms were reported in children with ADHD. This study supports the idea that emotion regulation, Efs, and clinical symptoms are interconnected. It also profiles the deficits in cognitive functioning and emotion regulation in two clinical groups, thus helping future intervention programs.

Intellectual profile in school-aged children with borderline intellectual functioning

BACKGROUND

Little is currently known about borderline intellectual functioning (BIF), a condition characterized by an intelligence quotient between one and two standard deviations below the average, that affects about 14% of the population.

AIMS

The present study aimed to analyze the intellectual profile of school-aged children with BIF.

METHOD AND PROCEDURE

The WISC-IV was administered to 204 children with BIF attending Italian primary and lower secondary school, and their profile was compared with that of a control group of typically developing (TD) children.

RESULTS

The WISC-IV profile of the children with BIF differed from that of the TD children, and the former's performance was worse than the latter's in all the measures considered. The children with BIF also showed significant differences between the four main factor indices, scoring lowest for working memory, while the TD control group's profile was flat (as expected on the grounds of standardization criteria). No differences were found between the profiles of children with versus without a comorbid neurodevelopmental disorder.

DISCUSSION

Our results support the hypothesis that individuals with BIF have a characteristic profile with specific weaknesses.

Acquisition of Reading and Intellectual Development Disorder

We propose a review of the literature of the studies investigating reading acquisition in intellectual deficiency (ID), with particular focus on the explanatory factors for reading difficulties. Indeed, we explore the role of intellectual efficiency, perceptual abilities, oral language development, phonological processing and memory. The study of reading acquisition in ID is a challenge because of a high degree of heterogeneity in the results which, together with other variables influencing learning and development. This review has allowed us to understand that there are multiple reasons why individuals with ID have difficulty learning to read. More specifically, there is a link between reading skills and certain cognitive skills, such as perception, oral language, phonological processing and working memory.

Die Entwicklung von Kindern mit umfassenden Lernschwierigkeiten im Verlauf der Grundschuljahre – Schulleistungen, Arbeitsgedächtnis, phonologische Informationsverarbeitung und Selbstkonzept

Zusammenfassung. Kinder mit Lernschwierigkeiten in der Schriftsprache oder im Rechnen weisen kognitive Defizite auf, welche sich primär auf die schulischen Erfolge auswirken und ferner mit einem schwachen schulischen Selbstkonzept einhergehen. Die vorliegende Arbeit geht der Frage nach, wie sich die Entwicklung der Schulleistungen, des schulischen Selbstkonzepts sowie die Entwicklung zugrundeliegender kognitiver Funktionen (Arbeitsgedächtnisfunktionen nach Baddeley und Hitch (1974) sowie weitere Merkmale der phonologischen Informationsverarbeitung nach Wagner und Torgesen (1987) ) von Kindern mit Lernschwierigkeiten von denen ohne Auffälligkeiten unterscheiden. Dazu wurden in einer Längsschnittstudie über einen Zeitraum von 2 Jahren Grundschulkinder (zu Beginn 8;9 Jahre alt) mit (a) einer Kombinierten Störung schulischer Fertigkeiten bei mindestens durchschnittlicher Intelligenz ( n = 30, IQ ≥ 85) mit (b) Lernschwierigkeiten und unterdurchschnittlicher Intelligenz im Rahmen einer Lernbehinderung ( n = 15, IQ < 85) und mit (c) lernunauffälligen und mindestens durchschnittlich intelligenten Grundschulkindern ( n = 55, IQ ≥ 85) verglichen. Die Ergebnisse zeigen, dass die schulischen Defizite bei beiden Gruppen mit Lernschwierigkeiten zeitlich stabil bestehen blieben. Bezüglich aller Komponenten der kognitiven Funktionen und der Entwicklung des schulischen Selbstkonzepts konnten keine signifikanten Unterschiede zwischen den beiden Lernstörungsgruppen gefunden werden, jedoch unterscheiden sich beide Gruppen signifikant von der Kontrollgruppe. Vor dem Hintergrund dieser Ergebnisse wird diskutiert, inwiefern es sich hier um eine homogene Lernstörungsgruppe handelt.

Short Forms of Wechsler Scales Assessing the Intellectually Gifted Children Using Simulation Data

Intellectual giftedness is usually defined in terms of having a very high Intellectual Quotient (IQ). The intellectual capacity is assessed by a standardized test such as the Wechsler Intelligence Scale for Children (WISC). However, the identification of intellectually gifted children (IGC) often remains time-consuming. A short-form WISC can be used as a screening instrument. The practitioners and researchers in this field can then make a more in-depth evaluation of the IGC's cognitive and socioemotional characteristics if needed. The aim of our study is thus to determine the best short tests, in terms of their psychometric qualities, for the identification of IGC. The current study is composed of three-step analyses. Firstly, we created nine IQs short forms (IQ_SF) with 2-subtests, and nine IQ_SF with 4-subtests from the WISC-IV (Wechsler, 2005). Secondly, we estimated psychometric parameters (i.e., reliability and validity) from empirical and simulated dataset with WISC-IV. The difference in the estimation of psychometric qualities of each IQ_SF from the simulated data is very close to those derived from empirical data. We thus selected the three best IQ_SF based on these psychometrics parameters estimated from simulated datasets. For each selected short form of the WISC-IV, we estimated the screening quality in our sample of IGC. Thirdly, we created IQ_SF with 2- and 4-subtests from the WISC-V (Wechsler, 2016) with simulated dataset. We then highlighted the three best short forms of WISC-V based on the estimated psychometric parameters. The results are interpreted in terms of validity, reliability and screening quality of IGC. In spite of the important changes in the WISC-V, our findings show that the 2-subtest form, Similitaries + Matrix Reasoning, and 4-subtest form, Similitaries + Vocabulary + Matrix Reasoning + Block Design, are the most efficient to identify the IGC at the two recent versions of Wechsler scales. Finally, we discuss the advantages and drawbacks of a brief assessment of intellectual aptitudes for the identification of the IGC.

Working Memory Updating Training Improves Mathematics Performance in Middle School Students With Learning Difficulties

Working memory (WM) deficit is considered the key cause of learning difficulties (LDs). Studies have shown that WM is plastic and thus can be improved through training. This positive effect is transferable to fluid intelligence and academic performance. This study investigated whether WM updating ability and academic performance in children with LDs could be improved through WM updating training and explored the effects of this training on the children’s brain activity. We used a running memory task lasting approximately 40 min per day for 28 days to train a group of 23 children with LDs (TLDs group). We also selected two control groups of 22 children with LDs (CLDs group) and 20 children without LDs (normal control [NC] group). The behavioral results of a pretest indicated that WM updating ability and academic performance in the TLDs and CLDs groups were significantly lower than those in the NC group before training. Compared with the CLDs group, the TLDs group exhibited significant performance improvement in a 2-back WM task, as well as in mathematical ability. Event-related potentials (ERPs) results suggested that the amplitudes of N160 (representative of visual recognition) and P300 (representative of updating processing, which is a valid index for updating WM) in the TLDs and CLDs groups were markedly lower than those in the NC group before training. In the TLDs group, these two components increased considerably after training, approaching levels similar to those in the NC group. The results of this study suggest that WM updating training can improve WM updating ability in children with LDs and the training effect can transfer to mathematical performance in such children. Furthermore, the participants’ brain activity levels can exhibit positive changes. This article provides experimental evidence that WM updating training could mitigate the symptoms of LDs to a certain degree.

Why Is Working Memory Performance Unstable? A Review of 21 Factors

In this paper, we systematically reviewed twenty-one factors that have been shown to either vary with or influence performance on working memory (WM) tasks. Specifically, we review previous work on the influence of intelligence, gender, age, personality, mental illnesses/medical conditions, dieting, craving, stress/anxiety, emotion/motivation, stereotype threat, temperature, mindfulness training, practice, bilingualism, musical training, altitude/hypoxia, sleep, exercise, diet, psychoactive substances, and brain stimulation on WM performance. In addition to a review of the literature, we suggest several frameworks for classifying these factors, identify shared mechanisms between several variables, and suggest areas requiring further investigation. This review critically examines the breadth of research investigating WM while synthesizing the results across related subfields in psychology.

Memory and linguistic/executive functions of children with borderline intellectual functioning

Children with Borderline Intellectual Functioning (BIF) have received a minimal amount of research attention and have been studied in conjunction with Intellectual and Developmental Disabilities. The present study intends to broaden the knowledge of BIF, by analyzing domains such as verbal memory and visual memory, as well as tasks that rely simultaneously on memory, executive functions, and language. A cross-sectional, comparison study was carried out between a group of 40 children with BIF (mean age = 10.03; 24 male and 16 female), and a control group of 40 normal children of the same age, gender, and socioeconomic level as the BIF group. The WISC-III Full Scale IQs of the BIF group ranged from 71 to 84. The following instruments were used: Word List, Narrative Memory, Rey Complex Figure, Face Memory, Rapid Naming (both RAN and RAS tests), and Verbal Fluency. The results showed deficits in children with BIF in verbal short-term memory, rapid naming, phonemic verbal fluency, and visual short-term memory, specifically in a visual recognition task, when compared with the control group. Long-term verbal memory was impaired only in older children with BIF and long-term visual memory showed no deficit. Verbal short-term memory stands out as a limitation and visual long-term memory as a strength. Correlations between the WISC-III and neuropsychological tests scores were predominantly low. The study expands the neuropsychological characterization of children with BIF and the implications of the deficits and strengths are stressed.

Academic Outcomes in Individuals With Childhood-Onset Epilepsy: Mediating Effects of Working Memory

OBJECTIVES

Academic difficulties are common in children with epilepsy, although little is known about the effect of various seizure-related and cognitive variables. Given that persistent seizures may negatively impact academics, and that working memory is predictive of academic abilities, we examined the effects of recent seizures and working memory on word reading, spelling, and arithmetic in pediatric epilepsy. We hypothesized that persistent seizures would be associated with lower working memory ability, which would in turn result in poorer academic performance.

METHODS

Our sample consisted of 91 children with epilepsy being treated at the Hospital for Sick Children in Toronto, Canada, who underwent neuropsychological testing between 2002 and 2009 to help determine surgical candidacy. Four to 11 years later, follow-up testing was conducted on both surgical (n=61) and non-surgical (n=30) patients. Seizure status was defined by the presence or absence of seizures within the preceding 12 months.

RESULTS

5000 bias-corrected bootstrap resamples with replacement were used to calculate the 95% confidence intervals (CIs) for the indirect effect of seizure status on academics through working memory, controlling for baseline academic functioning. Persistent seizures were associated with reduced working memory, which was in turn associated with lower reading (B=-4.64, 95% CI [-10.21, -1.30]), spelling (B=-7.09, 95% CI [-13.97, -2.56], and arithmetic scores (B=-8.04, 95% CI [-13.66, -3.58] at follow-up.

CONCLUSIONS

For children with intractable epilepsy, working memory deficits present a significant barrier to the development of academic skills. Working memory interventions may be a helpful adjunct to academic remediation in this population to facilitate academic progress. (JINS, 2017, 23, 594-604).

Intelligence and Verbal Short-Term Memory/Working Memory: Their Interrelationships from Childhood to Young Adulthood and Their Impact on Academic Achievement

Although recent developmental studies exploring the predictive power of intelligence and working memory (WM) for educational achievement in children have provided evidence for the importance of both variables, findings concerning the relative impact of IQ and WM on achievement have been inconsistent. Whereas IQ has been identified as the major predictor variable in a few studies, results from several other developmental investigations suggest that WM may be the stronger predictor of academic achievement. In the present study, data from the Munich Longitudinal Study on the Genesis of Individual Competencies (LOGIC) were used to explore this issue further. The secondary data analysis included data from about 200 participants whose IQ and WM was first assessed at the age of six and repeatedly measured until the ages of 18 and 23. Measures of reading, spelling, and math were also repeatedly assessed for this age range. Both regression analyses based on observed variables and latent variable structural equation modeling (SEM) were carried out to explore whether the predictive power of IQ and WM would differ as a function of time point of measurement (i.e., early vs. late assessment). As a main result of various regression analyses, IQ and WM turned out to be reliable predictors of academic achievement, both in early and later developmental stages, when previous domain knowledge was not included as additional predictor. The latter variable accounted for most of the variance in more comprehensive regression models, reducing the impact of both IQ and WM considerably. Findings from SEM analyses basically confirmed this outcome, indicating IQ impacts on educational achievement in the early phase, and illustrating the strong additional impact of previous domain knowledge on achievement at later stages of development.

Effect of Working Memory Updating Training on Retrieving Symptoms of Children With Learning Disabilities

Working memory (WM) deficiency is a primary reason for the poor academic performance of children with learning disabilities (LDs). Studies have shown that the WM of typical children could be improved through training, and WM training contributes to improving their fluid intelligence and academic achievement. However, few studies have investigated WM training for children with LDs, and results have been inconsistent. The present study examined the long-term effects of WM updating training and whether it can mitigate LD symptoms. Fifty-four children with LDs were recruited and divided randomly into a training or control group. The training group underwent adaptive running WM training for 20 days. Before and after training, the 2 groups completed a 2-back task, a digit span task (forward and backward), Raven's Standard Progressive Matrices test, and a scholastic attainment test (Chinese and math). The tests were repeated 6 months later. The results showed that, as compared with the controls, the training group exhibited significant improvements in the digit backward span task, 2-back task, and Raven's Standard Progressive Matrices. The math scores of the training group improved significantly by 6 months after the training. The results of this study suggest that WM updating training could mitigate the cognitive deficits of LDs and improve the WM capacity, fluid intelligence, and math scores of children with LDs. Moreover, the training effects could be maintained for at least 6 months.

Working Memory Maturation: Can We Get at the Essence of Cognitive Growth?

The theoretical and practical understanding of cognitive development depends on working memory, the limited information temporarily accessible for such daily activities as language processing and problem solving. In this article, I assess many possible reasons that working memory performance improves with development. A first glance at the literature leads to the weird impression that working memory capacity reaches adult levels during infancy but then regresses during childhood. In place of that unlikely explanation, I consider how infant studies may lead to overestimates of capacity if one neglects supports that the tasks provide, compared with adult-level tasks. Further development of working memory during the school years is also considered. Many investigators have come to suspect that working memory capacity may be constant after infancy because of various factors such as developmental increases in knowledge, filtering out of irrelevant distractions, encoding and rehearsal strategies, and pattern formation. With each of these factors controlled, though, working memory still improves during the school years. Suggestions are made for research to bridge the gap between infant and child developmental research, to understand the focus and control of attention in working memory and how these skills develop, and to pinpoint the nature of capacity and its development from infancy forward.

Working memory studies among individuals with intellectual disability: An integrative research review

BACKGROUND

Integrative research review infers generalizations about a substantive subject, summarizes the accumulated knowledge that research has left unresolved and generates a new framework on these issues. Due to methodological issues emerging from working memory (WM) studies in the population with non-specific intellectual disability (NSID) (N=64) between 1990-2014, it is difficult to conclude on WM performance in this population.

AIM

This integrative research review aimed to resolve literature conflicts on WM performance among individuals with NSID and to identify the conditions/moderators that govern their WM performance compared to controls with Typical development.

METHOD/PROCEDURE

We used the six stages of integrative research review: problem formulation, data collection, evaluation, data analysis, results, interpretation and discussion.

OUTCOMES AND RESULTS

The findings indicate two types of moderators that determine WM performance in the population with NSID: Participants' moderators (criteria for matching the ID and TD groups, CA and MA), and task moderators [the three WM components of Baddeley and Hitch's (1974) model and task load]. Only an interaction between the two moderators determines WM performance in this population. The findings indicate a hierarchy (from more to less preserved) in WM performance of individuals with NSID: The visuospatial tasks, then some of the executive functions tasks, and the phonological loop tasks being less preserved. Furthermore, at a low level of control, the performance of participants with NSID was preserved beyond the modality and vice versa.

CONCLUSIONS AND IMPLICATIONS

Modality and MA/intelligence determine WM performance of individuals with ID. Educators should prepare intervention programs take the impact of the two moderators into account.

The importance of working memory for school achievement in primary school children with intellectual or learning disabilities

BACKGROUND

Given the well-known relation between intelligence and school achievement we expect children with normal intelligence to perform well at school and those with intelligence deficits to meet learning problems. But, contrary to these expectations, some children do not perform according to these predictions: children with normal intelligence but sub-average school achievement and children with lower intelligence but average success at school. Yet, it is an open question how the unexpected failure or success can be explained.

AIMS

This study examined the role of working memory sensu Baddeley (1986) for school achievement, especially for unexpected failure or success.

METHOD AND PROCEDURES

An extensive working memory battery with a total of 14 tasks for the phonological loop, the visual-spatial sketchpad and central executive skills was presented in individual sessions to four groups of children differing in IQ (normal vs. low) and school success (good vs. poor).

OUTCOMES AND RESULTS

Results reveal that children with sub-average school achievement showed deficits in working memory functioning, irrespective of intelligence. By contrast, children with regular school achievement did not show deficits in working memory, again irrespective of intelligence.

CONCLUSIONS AND IMPLICATIONS

Therefore working memory should be considered an important predictor of academic success that can lead both to unexpected overachievement and failure at school. Individual working memory competencies should be taken into account with regard to diagnosis and intervention for children with learning problems.

Dyslexia and Substance Use in a University Undergraduate Population

BACKGROUND

A number of cognitive deficits are associated with dyslexia. However, only a limited amount of research has been performed exploring a putative link between dyslexia and substance use. As substance use is thought to involve a cognitive component, it is possible that the pattern of substance use would be different for dyslexic participants, when compared to nondyslexic controls. During the current study, a guiding hypothesis was that people with dyslexia would demonstrate less substance use than nondyslexic controls. Theories of memory activation, automaticity, and attentional bias in substance use suggest that cognitive components of substance use are important in the development and maintenance of continued substance use and it is thought that, at least some of these components, would be impaired in a dyslexic population.

OBJECTIVES

If the cognitive deficits displayed by dyslexics somehow impair the development of cognitive components of substance use, substance use for dyslexic participants may be less pronounced. This paper therefore examines this hypothesis by comparing substance use within dyslexic and nondyslexic participants, from an undergraduate population.

METHODS

This was an exploratory questionnaire-based study. Dyslexic participants (n = 35) were compared to control participants (n = 62) on a series of questions designed to measure their substance use history.

RESULTS

The results provided preliminary evidence of a difference between dyslexic and nondyslexic substance use. Dyslexics reported a substance use history that was significantly lower than nondyslexic controls.

CONCLUSIONS/IMPORTANCE

These results are interpreted in terms of cognitive deficits within dyslexia and with reference to the cognitive model of substance use.

A Meta-Analysis of Working Memory Deficits in Children With Learning Difficulties: Is There a Difference Between Verbal Domain and Numerical Domain?

Children with learning difficulties suffer from working memory (WM) deficits. Yet the specificity of deficits associated with different types of learning difficulties remains unclear. Further research can contribute to our understanding of the nature of WM and the relationship between it and learning difficulties. The current meta-analysis synthesized research on verbal WM and numerical WM among children with reading difficulties (RD), children with mathematics difficulties (MD), and children with reading and mathematics difficulties (RDMD). A total of 29 studies subsuming 110 comparisons were included. Results showed that compared to typically developing children, all learning difficulty groups demonstrated deficits in verbal WM and numerical WM, with RDMD children showing the most severe WM deficits. MD children and RD children showed comparable verbal WM deficits, but MD children showed more severe numerical WM deficits than RD children. Neither severity of learning difficulties nor type of academic screening emerged as a moderator of WM deficit profiles. Although the findings indicate the domain-general nature of WM deficits in RD, MD, and RDMD children, the numerical WM deficits of children with MD and RDMD may reflect the domain-specific nature of WM deficits.

Die Einflüsse des Migrationshintergrundes und psychischer Störungen auf kognitive Leistungsdaten einer SPZ-Inanspruchnahmepopulation

Zusammenfassung. Ein oft replizierter Befund ist, dass Kinder mit Migrationshintergrund schwächere Ergebnisse in Intelligenztests erzielen. Kognitive Leistungsmerkmale von Kindern mit F-Diagnosen gemäß ICD-10 wurden ebenfalls umfassend untersucht. Dennoch findet sich keine Studie, die explizit die Faktoren Störungsbild sowie Migrationshintergrund hinsichtlich kognitiver Leistungsdaten zueinander in Bezug setzt. Die vorliegende Studie untersucht im Rahmen eines allgemeinen linearen Modells den Einfluss des Faktors Migrationshintergrund sowie den gemeinsamen Einfluss mit der Variable psychische Störungen auf kognitive Leistungsdaten (Kaufman-Assessment Battery for Children [K-ABC], Melchers & Preuß, 2009 ). Zugrunde liegt eine SPZ-Stichprobe von 526 Vorschul- und Schulkindern einschließlich 238 Kindern mit Migrationshintergrund. Die meisten der Kinder weisen umschriebene Entwicklungsstörungen oder Verhaltensstörungen gemäß ICD-10 auf. Es konnten signifikante Haupteffekte für den Faktor Migrationshintergrund belegt werden, allerdings keine Interaktion mit dem Faktor Störungsbild. Die Ergebnisse unterstreichen den hohen Stellenwert vor allem des Migrationshintergrundes für die Erklärung kognitiver Leistungsdefizite.

Characterising the Profile of Everyday Executive Functioning and Relation to IQ in Adults with Williams Syndrome: Is the BRIEF Adult Version a Valid Rating Scale?

Although there is evidence of a distinct profile of executive dysfunction in Williams syndrome (WS), a rare genetically based neurodevelopmental disorder, the utility of informant reports of everyday executive function (EF) impairments and their relation to intelligence is not yet clear. Here we aimed to evaluate the functional impact of executive dysfunction in adults with WS and to establish the validity of child and adult versions of the most commonly used rating scale for EF assessment, the Behaviour Rating Inventory of Executive Function (BRIEF). We were also interested in whether distinct components of everyday EF relate to intelligence in WS. Parent report child (BRIEF-C) and adult (BRIEF-A) ratings were collected on 20 adults with WS (aged 18.5 to 53 years), with a mean IQ of 60.95 (SD = 17.67). Neuropsychological measures of EF included: The Shape School Test (Espy, 2007); select subdomains of EF from the Woodcock-Johnson III Tests of Cognitive Abilities, Australian Adaptation (WJ III COG); and select subdomains from the Vineland Adaptive Behaviour Scales, Second Edition—Parent Survey (Vineland-II). Results showed that the BRIEF-A, but not the BRIEF-C, was the most highly correlated with neuropsychological measures of EF, suggesting that it was a valid measure of the profile of EF impairments in adults with WS. The profile of everyday EF dysfunction revealed relative impairments in monitoring, working memory, planning and organisation in WS. In addition, both neuropsychological and rating scale measures showed an association between the shifting component of EF and intelligence. These findings indicate that the BRIEF-A is a valid measure of the multidimensional nature of real-world impairments in EF, and highlight its utility as a less labor intensive and low-cost screening tool for measuring specific EF impairments that could become the focus of targeted intervention in adults with WS.

Treating verbal working memory in a boy with intellectual disability

The present case study investigates the effects of a cognitive training of verbal working memory that was proposed for Davide, a 14-year-old boy diagnosed with mild intellectual disability. The program stimulated attention, inhibition, switching, and the ability to engage either in verbal dual tasks or in producing inferences after the content of a short passage had been encoded in episodic memory. Key elements in our program included (1) core training of target cognitive mechanisms; (2) guided practice emphasizing concrete strategies to engage in exercises; and (3) a variable amount of adult support. The study explored whether such a complex program produced "near transfer" effects on an untrained dual task assessing verbal working memory and whether effects on this and other target cognitive mechanisms (i.e., attention, inhibition, and switching) were long-lasting and produced "far transfer" effects on cognitive flexibility. The effects of the intervention program were investigated with a research design consisting of four subsequent phases lasting 8 or 10 weeks, each preceded and followed by testing. There was a control condition (phase 1) in which the boy received, at home, a stimulation focused on the visuospatial domain. Subsequently, there were three experimental training phases, in which stimulation in the verbal domain was first focused on attention and inhibition (phase 2a), then on switching and simple working memory tasks (phase 2b), then on complex working memory tasks (phase 3). A battery of neuropsychological tests was administered before and after each training phase and 7 months after the conclusion of the intervention. The main finding was that Davide changed from being incapable of addressing the dual task request of the listening span test in the initial assessment to performing close to the normal limits of a 13-year-old boy in the follow-up assessment with this test, when he was 15 years old.

Working Memory Functioning in Children With Poor Mathematical Skills

Previous research on working memory (WM) in children with poor mathematical skills has yielded heterogeneous results, possibly due to inconsistent consideration of the IQ–achievement discrepancy and additional reading and spelling difficulties. To examine the impact of both, the WM of 68 average-achieving and 68 low-achieving third-graders in mathematics was assessed. Preliminary analyses showed that poor mathematical skills were associated with poor WM. Afterwards, children with isolated mathematical difficulties were separated from those with additional reading and spelling difficulties. Half of each group fulfilled the IQ–achievement discrepancy, resulting in a 2 (additional reading and spelling difficulties: yes/no) by 2 (IQ–achievement discrepancy: yes/no) factorial design. Analyses revealed that not fulfilling the IQ–achievement discrepancy was associated with poor visual WM, whereas additional reading and spelling difficulties were associated with poor central executive functioning in children fulfilling the IQ–achievement discrepancy. Therefore, WM in children with poor mathematical skills differs according to the IQ–achievement discrepancy and additional reading and/or spelling difficulties.

From Learning to Memory: What Flies Can Tell Us about Intellectual Disability Treatment

Intellectual disability (ID), previously known as mental retardation, affects 3% of the population and remains without pharmacological treatment. ID is characterized by impaired general mental abilities associated with defects in adaptive function in which onset occurs before 18 years of age. Genetic factors are increasing and being recognized as the causes of severe ID due to increased use of genome-wide screening tools. Unfortunately drug discovery for treatment of ID has not followed the same pace as gene discovery, leaving clinicians, patients, and families without the ability to ameliorate symptoms. Despite this, several model organisms have proven valuable in developing and screening candidate drugs. One such model organism is the fruit fly Drosophila. First, we review the current understanding of memory in human and its model in Drosophila. Second, we describe key signaling pathways involved in ID and memory such as the cyclic adenosine 3',5'-monophosphate (cAMP)-cAMP response element binding protein (CREB) pathway, the regulation of protein synthesis, the role of receptors and anchoring proteins, the role of neuronal proliferation, and finally the role of neurotransmitters. Third, we characterize the types of memory defects found in patients with ID. Finally, we discuss how important insights gained from Drosophila learning and memory could be translated in clinical research to lead to better treatment development.

Learning of writing letter-like sequences in children with physical and multiple disabilities

This study compared implicit and explicit learning instructions in hand writing. Implicit learning is the ability to acquire a new skill without a corresponding increase in knowledge about the skill. In contrast, explicit learning uses declarative knowledge to build up a set of performance rules that guide motor performance or skills. Explicit learning is dependent on working memory, implicit learning is not. Therefore, implicit learning was expected to be easier than explicit learning in children in special education, given their expected compromised working memory. Two groups of children (5-12 years) participated, children in special education with physical or multiple disabilities (study group, n=22), and typically developing controls (n=32). Children learned to write letter-like patterns on a digitizer by tracking a moving target (implicitly) and verbal instruction (explicitly). We further tested visual working memory, visual-motor integration, and gross manual dexterity. Learning curves were similar for both groups in both conditions; children in the study group did learn both implicitly and explicitly. Motor performance was related to the writing task. In contrast to our hypothesis, visual working memory was not an important factor in the explicit condition. These results shed new light on the conceptual difference between implicit and explicit learning, and the role of working memory therein.

Borderline intellectual functioning: a systematic literature review

The literature related to people with borderline intellectual functioning (BIF) was systematically reviewed in order to summarize the present knowledge. Database searches yielded 1,726 citations, and 49 studies were included in the review. People with BIF face a variety of hardships in life, including neurocognitive, social, and mental health problems. When adults with BIF were compared with the general population, they held lower-skilled jobs and earned less money. Although some risk factors (e.g., low birth weight) and preventive factors (e.g., education) were reported, they were not specific to BIF. The review finds that, despite the obvious everyday problems, BIF is almost invisible in the field of research. More research, societal discussion, and flexible support systems are needed.

Numerical magnitude processing deficits in children with mathematical difficulties are independent of intelligence

Developmental dyscalculia (DD) is thought to arise from difficulties in the ability to process numerical magnitudes. Most research relied on IQ-discrepancy based definitions of DD and only included individuals with normal IQ, yet little is known about the role of intelligence in the association between numerical magnitude processing and mathematical difficulties (MD). The present study examined numerical magnitude processing in matched groups of 7- to 8-year-olds (n=42) who had either discrepant MD (poor math scores, average IQ), nondiscrepant MD (poor math scores, below-average IQ) or no MD. Both groups of children with MD showed similar impairments in numerical magnitudes processing compared to controls, suggesting that the association between numerical magnitude processing deficits and MD is independent of intelligence.

Do children with cerebral palsy benefit from computerized working memory training? Study protocol for a randomized controlled trial

Background

Cerebral palsy (CP) is the most common motor disability in childhood (2 to 3 per 1000 live births), and is frequently accompanied by cognitive impairments and behavioural problems. Children with CP are at increased risk of attention deficit disorder with or without hyperactivity (Attention Deficit Disorder (ADD)/Attention Deficit Hyperactivity Disorder (ADHD)) including working memory deficits. The primary aim of this study is to evaluate if cognitive training may improve working memory in children with CP.

Methods/Designs

The study is an investigator-blinded, randomized controlled trial with a stepped-wedge design that will include 115 schoolchildren with CP. Eligible for participation are children with CP, aged 7 to 15 years, who are able to follow instructions and handle a computer mouse. Exclusion criteria are the presence of photosensitive epilepsy, Gross Motor Function Classification System (GMFCS) level V (most severe CP) (Phys Ther 80: 974-985, 2000) and severe visual or hearing impairments. Following assessment of eligibility and baseline cognitive assessment the participants will be randomized to either cognitive working memory training or treatment-as-usual (‘control group’). The intervention is a computer-based working memory training program consisting of 25 daily sessions to be performed over a 5 to 6-week period at home. A neuropsychological assessment will be performed before and 4 to 6 weeks after completed training. When the latter assessment has been completed in the intervention group, the ‘control group’ will start on the same training program. Both groups will meet for a final neuropsychological assessment six months after completed training by an examiner unaware of group adherence.

Discussion

There is limited evidence for the effect of most interventions in children with CP, and evidence is completely lacking for interventions aiming to improve deficits in cognition, learning and behaviour. The proposed multicenter study, will bring forth comprehensive information about cognitive, neuropsychological, and daily-life functioning in children with CP aged between 7 and 15 years. In addition, the study will be the first to evaluate the effects of an intervention method to improve working memory in children with CP. If successful, computer-based working memory training may represent an efficient and cost-effective intervention for this group of children.

Trial registration

ClinicalTrials.gov Identifier: NCT02119364

Phonological short-term memory impairment and the word length effect in children with intellectual disabilities

There is mounting evidence that children and adolescents with intellectual disabilities (ID) of nonspecific aetiology perform poorer on phonological short-term memory tasks than children matched for mental age indicating a structural deficit in a process contributing to short-term recall of verbal material. One explanation is that children with ID of nonspecific aetiology do not activate subvocal rehearsal to refresh degrading memory traces. However, existing research concerning this explanation is inconclusive since studies focussing on the word length effect (WLE) as indicator of rehearsal have revealed inconsistent results for samples with ID and because in several existing studies, it is unclear whether the WLE was caused by rehearsal or merely appeared during output of the responses. We assumed that in children with ID only output delays produce a small WLE while in typically developing 6- to 8-year-olds rehearsal and output contribute to the WLE. From this assumption we derived several predictions that were tested in an experiment including 34 children with mild or borderline ID and 34 typically developing children matched for mental age (MA). As predicted, results revealed a small but significant WLE for children with ID that was significantly smaller than the WLE in the control group. Additionally, for children with ID, a WLE was not found for the first word of each trial but the effect emerged only in later serial positions. The findings corroborate the notion that in children with ID subvocal rehearsal does not develop in line with their mental age and provide a potential explanation for the inconsistent results on the WLE in children with ID.

Working memory and executive functions: effects of training on academic achievement

The aim of this review is to illustrate the role of working memory and executive functions for scholastic achievement as an introduction to the question of whether and how working memory and executive control training may improve academic abilities. The review of current research showed limited but converging evidence for positive effects of process-based complex working-memory training on academic abilities, particularly in the domain of reading. These benefits occurred in children suffering from cognitive and academic deficits as well as in healthy students. Transfer of training to mathematical abilities seemed to be very limited and to depend on the training regime and the characteristics of the study sample. A core issue in training research is whether high- or low-achieving children benefit more from cognitive training. Individual differences in terms of training-related benefits suggested that process-based working memory and executive control training often induced compensation effects with larger benefits in low performing individuals. Finally, we discuss the effects of process-based training in relation to other types of interventions aimed at improving academic achievement.

Conceptual abilities of children with mild intellectual disability: analysis of wisconsin card sorting test performance

BACKGROUND

The ability to generate and flexibly change concepts is of great importance for the development of academic and adaptive skills. This paper analyses the conceptual reasoning ability of children with mild intellectual disability (MID) by their achievements on the Wisconsin Card Sorting Test (WCST).

METHOD

The sample consisted of 95 children with MID aged between 10 years and 13 years 11 months. The following variables from the WCST were analysed: number of categories completed, initial conceptualisation, total number of errors, non-perseverative errors, perseverative errors, number of perseverative responses, and failures to maintain set.

RESULTS

The observed WCST predictive variables account for 79% of the variability in the number of categories completed (p < .000). The total number of errors was the most significant predictor of performance on the WCST.

CONCLUSION

We can conclude that there is a significant progress of conceptual abilities between the age of 13 years to 13 years 11 months, compared to other assessed age groups. The results of our research suggests that the development of mental set flexibility is the basis of progress in conceptual abilities, thus intervention programs should offer specially designed activities that vary in their attentional demands, content, conceptual patterns, and actions required.

Math practice and its influence on math skills and executive functions in adolescents with mild to borderline intellectual disability

Adolescents with mild to borderline intellectual disability (MBID) often complete schooling without mastering basic math skills, even though basic math is essential for math-related challenges in everyday life. Limited attention to cognitive skills and low executive functioning (EF) may cause this delay. We aimed to improve math skills in an MBID-sample using computerized math training. Also, it was investigated whether EF and math performance were related and whether computerized math training had beneficial effects on EF. The sample consisted of a total of 58 adolescents (12-15 years) from special education. Participants were randomly assigned to either the experimental group or a treatment as usual (TAU) group. In the experimental condition, participants received 5 weeks of training. Math performance and EF were assessed before and after the training period. Math performance improved equally in both groups. However, frequently practicing participants improved more than participants in the control group. Visuo-spatial memory skills were positively related to addition and subtraction skills. Transfer effects from math training to EF were absent. It is concluded that math skills may increase if a reasonable effort in practicing math skills is made. The relation between visuo-spatial memory skills provides opportunities for improving math performance.

Prenatal tobacco exposure predicts differential brain function during working memory in early adolescence: a preliminary investigation

Children prenatally exposed to tobacco exhibit higher rates of learning and emotional-behavioral problems related to worse working memory performance. Brain function, however, among tobacco exposed children while performing a working memory task has not previously been examined. This study compared the brain function of tobacco-exposed (n = 7) and unexposed (n = 11) 12-year-olds during a number N-back working memory task using an event-related functional magnetic resonance imaging (fMRI) design. Prenatal alcohol exposure, neonatal medical problems, environmental risk, and sex were statistically controlled. Tobacco-exposed children showed greater activation in inferior parietal regions, whereas unexposed children showed greater activation in inferior frontal regions. These differences were observed in the context of correct responses, suggesting that exposed and unexposed children use different brain regions and approaches to succeed in working memory tasks. Implications for future research and intervention are discussed.

Rethinking ADHD and LD in DSM-5: proposed changes in diagnostic criteria

The Diagnostic and Statistical Manual of Mental Disorders (DSM) is currently undergoing revision that will lead to a fifth edition (DSM-5) in 2013. This article first provides a brief synopsis of the DSM-5 administrative structure, procedures, and guiding principles to enhance understanding of how changes are made in the DSM. The next two sections (on attention-deficit/hyperactivity disorder and learning disorders, respectively) highlight the major concerns and controversies surrounding the DSM-IV diagnostic criteria for these two disorders and provide a rationale for the proposed changes to the criteria, along with a commentary on the empirical evidence on which the proposed changes were based.

Cognitive Skills and Academic Achievement of Deaf Children with Cochlear Implants

Objective

To compare cognitive performance between children with cochlear implants (CI) and normal-hearing peers; provide information about correlations between cognitive performance, basic academic achievement, and medical/audiological and social background variables; and assess the predictor quality of these variables for cognition.

Study Design

Cross-sectional study with comparison group, diagnostic test assessment.

Setting

Data were collected in the authors’ clinic (children with CI) and in Austrian schools (normal-hearing children).

Subjects and Methods

Forty children with CI (of the initial 65 children eligible for this study), aged 7 to 11 years, and 40 normal-hearing children, matched by age and sex, were tested with (a) the Culture Fair Intelligence Test (CFIT); (b) the Number Sequences subtest of the Heidelberger Rechentest 1-4 (HRT); (c) Comprehension, (d) Coding, (e) Digit Span, and (f) Vocabulary subtests of HAWIK III (German WISC III); (g) the Corsi Block Tapping Test; (h) the Arithmetic Operations subtests of the HRT; and (i) Salzburger Lese–Screening (SLS, reading). In addition, medical, audiological, social, and educational data from children with CI were collected.

Results

The children with CI equaled normal-hearing children in (a), (d), (e), (g), (h), and (i) and performed significantly worse in (b), (c) and (f). Background variables correlate significantly with cognitive skills and academic achievement. Medical/audiological variables explain 44.3% of the variance in CFT1 (CFIT, younger children). Social variables explain 55% of CFT1 and 24.5% of the Corsi test.

Conclusions

This study augments the knowledge about cognitive skills and academic skills of children with CI. Cognitive performance is dependent on the early feasibility to hear and the social/educational background of the family.

Strengths and weaknesses in executive functioning in children with intellectual disability

Children with intellectual disability (ID) were given a comprehensive range of executive functioning measures, which systematically varied in terms of verbal and non-verbal demands. Their performance was compared to the performance of groups matched on mental age (MA) and chronological age (CA), respectively. Twenty-two children were included in each group. Children with ID performed on par with the MA group on switching, verbal executive-loaded working memory and most fluency tasks, but below the MA group on inhibition, planning, and non-verbal executive-loaded working memory. Children with ID performed below CA comparisons on all the executive tasks. We suggest that children with ID have a specific profile of executive functioning, with MA appropriate abilities to generate new exemplars (fluency) and to switch attention between tasks, but difficulties with respect to inhibiting pre-potent responses, planning, and non-verbal executive-loaded working memory The development of different types of executive functioning skills may, to different degrees, be related to mental age and experience.

Relationships Between Working Memory and Academic Skills: Are There Differences Between Children With Intellectual Disabilities and Typically Developing Children?

In typically developing children, working memory is linked to academic skills. However, little is known about the role working memory plays for learning in children with intellectual disabilities (ID). Therefore, the aims of this study were to examine whether different working memory functions are related to reading, spelling, and calculating in children with ID of nonspecific etiology and whether these relationships are different from the ones found in typically developing children. Forty-seven children with mild-to-borderline ID and 47 children matched for mental age were tested. Although in typically developing children, only phonological short-term memory tasks were predictive for literacy, for children with ID, visuospatial working memory tasks also accounted for variance. In typically developing children, calculation skills were predicted by phonological working memory tasks, whereas visuospatial working memory resources were crucial for children with ID. Several possible explanations are discussed for discrepancies in prediction patterns.

Functional deficits in phonological working memory in children with intellectual disabilities

Recent studies indicate that children with intellectual disabilities have functional limitations primarily in the phonological loop of working memory (Baddeley, 1986). These findings are indicative of a specific structural deficit. Building on this research, the present study examines whether it is possible to identify specific phonological subfunctions as causal factors in these qualitative deviations from typical development found in children with intellectual disabilities. In a three-group design, specific subfunctions of phonological working memory were examined in students of the same mental age (one group of 15-year-olds with mild intellectual disability [IQ 50-69], one group of 10-year-olds with borderline intellectual disability [IQ 70-84], and one group of 7-year-olds of average intelligence [IQ 85-115]). The automatic activation of the subvocal rehearsal process was operationalized by the word-length effect; the size of the phonological store, by a task involving repetition of nonwords of differing syllable length; and accuracy of processing, by both the phonological similarity effect and the quality of acoustic presentation of the nonword repetition task (distorted vs. undistorted item presentation). The results revealed impairment of the phonological store only in terms of reduced storage capacity, and showed that this deficit increased with length of the item sequences to be remembered. However, this deficit was observed only in children with mild intellectual disability; the performance of children with borderline intellectual disability corresponded with that of a control group of 7-year-olds matched for mental age. The findings are discussed in the context of the two-component model of the phonological loop. They indicate that deficits in storage capacity are associated with deficits in language development and thus seem to be one of the causes of cognitive impairment in individuals with mild intellectual disability.

Executive functions in individuals with intellectual disability

The aim of the present study was to investigate executive functions in adults with intellectual disability, and compare them to a closely matched control group longitudinally for 5 years. In the Betula database, a group of adults with intellectual disability (ID, n=46) was defined from measures of verbal and non-verbal IQ. A control group, with two people for every person with intellectual disability (n=92), was chosen by matching on the following criterion in order of priority: IQ higher than 85, age, sex, sample, level of education, and years of education. Three types of tasks of executive functions were included on two occasions, with 5 years between testing sessions: The Tower of Hanoi, executively loaded dual task versions of word recall, and verbal fluency. Adults with ID showed significant impairments on verbal fluency and on the executively loaded dual task word recall task (at encoding but not at recall). There were no group differences on the Tower of Hanoi. No significant differences between the two test occasions were found. The results are interpreted in terms of individuals with ID having problems with speed of accessing lexical items and difficulties with working memory-related executive control at encoding, which includes shifting between tasks. There are, however, not necessarily problems with inhibition. The dual task results additionally imply that the adults with intellectual disability were more sensitive to strategy interruptions at encoding, but that dividing attention at recall did not have such detrimental effects.

Working memory structure in 10- and 15-year old children with mild to borderline intellectual, disabilities

The validity of Baddeley's working memory model within the typically developing population, was tested. However, it is not clear if this model also holds in children and adolescents with mild to, borderline intellectual disabilities (ID; IQ score 55-85). The main purpose of this study was therefore, to explore the model's validity in this population. Several verbal and visuo-spatial STM and WM tasks, were administered to 115 children with mild to borderline ID (mean age 10 years) and to 98, adolescents with mild to borderline ID (mean age 15). Structural equation modeling (LISREL) shows, that Baddeley's working memory model does not fit the data of the 10-year and 15-year old, participants. Principal components analyses on the other hand show a hazy pattern with on the one, side an indication for a 'general' component with loadings of visuo-spatial short-term memory and, working memory tasks and a separate verbal short-term memory component. On the other hand there, is also an indication of a modality specific memory structure; a visuo-spatial- versus a verbal, component. A straight-forward dichotomy between STM and WM indicates apparently an, oversimplification, at least it is for children and adolescents with mild to borderline ID.

Unterscheiden sich Subgruppen rechengestörter Kinder in ihrer Arbeitsgedächtniskapazität, im basalen arithmetischen Faktenwissen und in den numerischen Basiskompetenzen?

Zusammenfassung. Die vorliegende Studie beschäftigt sich mit kognitiven Merkmalen bei Subgruppen rechenschwacher Kinder. Dabei wurde im Einzelnen überprüft, ob Leistungsbeeinträchtigungen in der bereichsübergreifenden Arbeitsgedächtniskapazität sowie in bereichsspezifischen Fähigkeiten des basalen arithmetischen Faktenabrufs und der numerischen Basiskompetenzen vorliegen und ob Unterschiede zwischen rechenschwachen Kindern mit und ohne zusätzliche Schriftsprachschwierigkeiten bestehen. Hierzu wurden 22 Kinder mit der Diagnose Rechenstörung (F 81.2 nach ICD-10), 30 Kinder mit der Diagnose Kombinierte Störung schulischer Fertigkeiten (F 81.3 nach ICD-10) und 30 nach Alter parallelisierte Kontrollkinder mit einer umfangreichen Testbatterie in Einzelsitzungen untersucht. Die Ergebnisse belegen für alle rechengestörten Kinder Defizite in allen drei Bereichen, wobei die Kinder mit kombinierten Schulleistungsstörungen im Vergleich zu den isoliert gestörten Kindern umfassendere Beeinträchtigungen aufweisen.

Working memory and executive function profiles of individuals with borderline intellectual functioning

BACKGROUND

The aim of the present study was to investigate the following issues: (1) Do students with borderline intellectual functioning have a pervasive pattern of impaired working memory skills across both verbal and visuo-spatial domains? (2) Is there evidence for impairment in executive function skills, and which tasks indicate greater deficits? and (3) Which executive function tasks can effectively identify students with low IQ from typically developing peers?

METHOD

Students with borderline intellectual functioning (low-IQ; IQ standard scores were between 70 and 85) were age-matched with typically developing students (IQ standard scores >95). They were administered a range of working memory and executive function measures.

RESULTS

The results show that students with low IQ have pervasive working memory and executive function deficits. Specifically, visuo-spatial working memory and the Sorting task were the best single predictors that reliably classified students with low IQ.

CONCLUSIONS

Implications for education are discussed in the context of appropriate diagnosis and support in the classroom.

Effectiveness of a computerised working memory training in adolescents with mild to borderline intellectual disabilities

BACKGROUND

The goal of this study is to evaluate the effectiveness of a computerised working memory (WM) training on memory, response inhibition, fluid intelligence, scholastic abilities and the recall of stories in adolescents with mild to borderline intellectual disabilities attending special education.

METHOD

A total of 95 adolescents with mild to borderline intellectual disabilities were randomly assigned to either a training adaptive to each child's progress in WM, a non-adaptive WM training, or to a control group.

RESULTS

Verbal short-term memory (STM) improved significantly from pre- to post-testing in the group who received the adaptive training compared with the control group. The beneficial effect on verbal STM was maintained at follow-up and other effects became clear at that time as well. Both the adaptive and non-adaptive WM training led to higher scores at follow-up than at post-intervention on visual STM, arithmetic and story recall compared with the control condition. In addition, the non-adaptive training group showed a significant increase in visuo-spatial WM capacity.

CONCLUSION

The current study provides the first demonstration that WM can be effectively trained in adolescents with mild to borderline intellectual disabilities.