Working Memory Deficits in Children With Dyslexia: A Longitudinal Perspective

• In Event: 61.083 - Working Memory and Learning Disabilities

Abstract

Working memory deficits have recently been identified as possible causal factors underlying learning disabilities, and specific patterns of impairment have been found for different learning disorders, i.e. a deficient functioning of the phonological loop for children with dyslexia. Yet not much is known about the specific dysfunctions of children with problems either in reading or writing or both and about the development of working memory of these children. Given this theoretical background the questions of the study were: Can specific working memory deficits be detected for children with readings vs. writing problems? Do possible deficits persist over time? Is the longitudinal development of working memory a good predictor for school achievement in children with reading and/or spelling disorders?
A total of 138 children from four different groups took part in the longitudinal study: 30 children with reading problems (age 8;9 years, IQ 100), 36 children with spelling problems (age 8;8 years, IQ 100), 36 children with reading and spelling problems (age 8;7 years, IQ 102) and a typically developing control group of 36 children with no reading or spelling problems (age 8;8, IQ 99).
Data were available for intelligence and scholastic skills (mathematics, reading and spelling) in order to match the four groups at the beginning of the longitudinal study. In accordance with the working memory model of Baddeley (1986) a rather long battery of working memory tasks was presented to the children in individual sessions. The phonological loop was examined by different memory span tasks (memory span for mono-syllabic and three-syllable words, numbers, non-word repetition) and an articulation rate. To test the visual-spatial sketchpad children were presented with memory span tasks for locations and patterns, and the central executive functioning was tested by backward spans (digit span backward, word span backward and color span backward), a complex span task, a counting span task, go/nogo and a stroop task. Data of working memory functions were collected three times with an interval of one year. Several 2 (reading problems yes/no) by 2 (spelling problems yes/no) analyses of variance for repeated measures revealed the following main results: working memory improves over time in all groups, but children with reading or spelling problems did not catch up; measures of reading and writing also stay below the control group. Therefore we must conclude that working memory problems as well as school achievement problems persist over time. In a last step of analyses we divided the groups with reading and/or writing problems into those children who overcome their academic deficits and those who do not, and found that working memory is not able to differentiate between those groups. Therefore working memory does not seem to be a good predictor for improving academic skills although it is regarded as an important causal factor.

Baddeley, A. D. (1986). Working memory. Oxford: University Press.

Authors

• Claudia Mähler, University of Hildesheim

• Kirsten Schuchardt, The University of Hildesheim