Stefanie Pieters

Can we predict mathematical learning disabilities from symbolic and non‐symbolic comparison tasks in kindergarten? Findings from a longitudinal study

BACKGROUND The ability to compare numbers, as the most basic form of number sense, has been related to arithmetical achievement. AIMS The current study addressed the predictive value of non-symbolic and symbolic (number word (NW) and Arabic number (AN)) comparison for arithmetics by means of a longitudinal design. SAMPLE Sixteen children with mathematical disabilities (MD), 64 low achievers (LA), and 315 typical achieving (TA) children were followed from kindergarten till grade 2. METHOD The association of comparison skills with arithmetical skills in grades l and 2 was studied. The performances of MD, LA and TA children were compared. RESULTS Regression analyses showed that non-symbolic skills in kindergarten were predictively related to arithmetical achievement 1 year later and fact retrieval 2 years later. AN comparison was predictively related to procedural calculation 2 years later. In grade 2, there was an association between both symbolic tasks and arithmetical achievement. Children with MD already had deficits in non-symbolic and symbolic AN comparison in kindergarten, whereas in grade 2 the deficits in processing symbolic information remained. CONCLUSIONS The combination of non-symbolic and symbolic deficits represents a risk of developing MD.

How common are motor problems in children with a developmental disorder: rule or exception?

BACKGROUND Few co-morbidity studies have been conducted since the Leeds Consensus Statement on developmental co-ordination disorder (DCD) in 2006. In this Statement, international cut-offs and inclusion criteria were agreed and consequently, the status of DCD changed. Furthermore, most existing co-morbidity studies are small clinical studies, rather than epidemiological studies, resulting in a broad range of co-morbidity rates. DCD has a higher incidence for boys in comparison with girls; questions arise if this preponderance remains the same in combination with other developmental disorders. Therefore, in this study we aimed to determine co-morbidity and gender differences of motor problems in children with a pervasive developmental disorder, a hyperkinetic disorder and/or a speech, language or learning disability. METHODS Profiles of 3608 children (mean age: 9 years 1 month) referred to rehabilitation centres for behavioural, developmental and sensorineural disorders were studied. RESULTS Motor problems were reported in one-fifth of the total sample. Co-morbidity of motor problems in specific disorders varied from almost one-fourth to more than one-third. The male/female ratio was significantly higher in children with motor problems and two or more other disorders, compared with children with motor problems and less than two other disorders. CONCLUSIONS This study indicates that co-morbidity of motor problems with other clinical disorders is not exceptional and developmental deviance is seldom specific to one domain. However, current co-morbidity studies tend to overestimate the number of children with motor problems. In addition, there may be different patterns of symptoms between the genders. These findings stress the importance of assessing motor skills in children with various developmental disorders.

Mathematical Problems in Children with Developmental Coordination Disorder.

Developmental coordination disorder (DCD) is a heterogeneous disorder, which is often co-morbid with learning disabilities. However, mathematical problems have rarely been studied in DCD. The aim of this study was to investigate the mathematical problems in children with various degrees of motor problems. Specifically, this study explored if the development of mathematical skills in children with DCD is delayed or deficient. Children with DCD performed significantly worse for number fact retrieval and procedural calculation in comparison with age-matched control children. Moreover, children with mild DCD differed significantly from children with severe DCD on both number fact retrieval and procedural calculation. In addition, we found a developmental delay of 1 year for number fact retrieval in children with mild DCD and a developmental delay of 2 years in children with severe DCD. No evidence for a mathematical deficit was found. Diagnostic implications are discussed.

Identifying Subtypes Among Children With Developmental Coordination Disorder and Mathematical Learning Disabilities, Using Model-Based Clustering

A relationship between motor and mathematical skills has been shown by previous research. However, the question of whether subtypes can be differentiated within developmental coordination disorder (DCD) and/or mathematical learning disability (MLD) remains unresolved. In a sample of children with and without DCD and/or MLD, a data-driven model-based clustering was used to identify subgroups of individuals with relatively homogeneous profiles on measures associated with motor and mathematical skills. One subgroup of children with motor problems was found based on motor variables. Based on mathematical variables, two clinical clusters were found: a subtype with number fact retrieval problems and a subtype with procedural calculation problems. Clustering with motor and mathematical skills revealed two clinical clusters: a cluster with number fact retrieval as well as procedural calculation problems and below average motor and visual-motor integration skills. A second cluster of children had only procedural calculation and visual-motor problems. Our results raise questions about the usefulness of placing children who have below average mathematical skills into a single diagnostic category. Furthermore, we inform ongoing debates about the overlap between DCD and MLD, as below average motor skills were found in both MLD subgroups, although a different motor profile is linked to a different mathematical profile.

1430 Psychosocial Treatment for Developmental Disorders of Speech and Language and Developmental Disorders of Scholastic Skills: Evidence and Care Organization.

Objectives: To summarize scientific evidence for individual psychosocial treatment of developmental disorders of speech and language (DD-L), and developmental disorders of scholastic skills (DDSch). To describe care organization for these disorders in 7 Western countries. Methodology: EBM literature review including systematic reviews, meta-analyses, randomized controlled trials and quasi-experimental studies. Questionnaires sent to renowned experts in France, Germany, the Netherlands, Finland, UK, and Switzerland; description of the Belgian situation. Results: In the short term, speech and language interventions for expressive phonological or vocabulary difficulties are effective; long term effects are not well-studied. In a few studies, no difference was found between treatment by trained parents or clinicians, or between individual and group therapy. For treatment of receptive language difficulties, only few studies are available suggesting little effects. Effective reading programs for reading disabilities should include training of the alphabetic principle and phonological awareness, and integration of these elements with comprehension and fluency skills. For mathematical disorders, too few publications are available to conclude. Very few studies evaluated treatment intensity and duration, or the differences between monoand multidisciplinary treatment. Publications on treatment of co-morbid developmental or behavioral disorders were also lacking. In most countries, multidisciplinary treatment (2 disciplines or more) is almost standard for DD-L and DD-Sch. Governmental responsibility for organization and funding belongs mostly to health and educational departments together. Conclusion: It seems standard in Western societies to provide multidisciplinary treatment for DD-L and DD-Sch, but effectiveness of this strategy has been little evaluated.