Working Memory Deficits in Children With Specific Learning Disorders

Kirsten Schuchardt,Claudia Maehler,Marcus Hasselhorn

doi:10.1177/0022219408317856

Abstract

This article examines working memory functioning in children with specific developmental disorders of scholastic skills as defined by ICD-10. Ninety-seven second to fourth graders with a minimum IQ of 80 are compared using a 2 x 2 factorial (dyscalculia vs. no dyscalculia; dyslexia vs. no dyslexia) design. An extensive test battery assesses the three subcomponents of working memory described by Baddeley (1986): phonological loop, visual-spatial sketchpad, and central executive. Children with dyscalculia show deficits in visual-spatial memory; children with dyslexia show deficits in phonological and central executive functioning. When controlling for the influence of the phonological loop on the performance of the central executive, however, the effect is no longer significant. Although children with both reading and arithmetic disorders are consistently outperformed by all other groups, there is no significant interaction between the factors dyscalculia and dyslexia.

Highlights

This article examines working memory functioning in children with specific developmental disorders of scholastic skills as defined by ICD-10
Scores on the three components of working memory tasks were entered in multivariate analyses of variance (MANOVAs) with presence or absence of dyscalculia and dyslexia as fixed factors
The scores on the seven tasks assessing phonological loop functioning were entered into a multivariate analysis of variance (MANOVA)

Summary

Introduction

This article examines working memory functioning in children with specific developmental disorders of scholastic skills as defined by ICD-10. Recognized criteria for their diagnosis are specified in the conventional classification systems: the International Classification of Diseases (ICD-10) published by the World Health Organization (2005), and the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revision (DSM-IV-TR) published by the American Psychiatric Association (2000) According to these systems, learning disorders are present when individuals’ abilities in the domains of reading, spelling, or arithmetic are substantially below their expected potential given their age, general intelligence, and education. It is undisputed that children with specific reading disabilities have deficits in phonological processing and storage (Pickering, 2006b; Swanson, 2006; Vellutino et al, 2004), and there is evidence to suggest that they experience deficits in central executive functioning (Landerl, Bevan, & Butterworth, 2004; Palmer, 2000; Siegel & Ryan, 1989; Swanson, 1993, 1999). There are relatively few reports of impairments in the visual–spatial working memory of reading disabled children, (Eden & Stein, 1995; Howes, Bigler, Burlingame, & Lawson, 2003; Kibby, Marks, Morgan, & Long, 2004; O’Shaughnessy & Swanson, 1998; Pickering, 2006b)

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