Working Memory in Portuguese Children With Developmental Dyslexia.

A Portuguese sample of 50 children with developmental dyslexia (DD) and 50 typical readers (TR) who were matched for age (8-12 years old) were tested on measures of working memory. Relative to the TR, the children with DD performed significantly worse on phonological loop (PL) and central executive (CE) tasks; however, they exhibited no impairments on visuospatial sketchpad (VSSP) tasks. After controlling for the influence of the PL, the group differences in CE tasks were no longer significant. The results of a receiver-operating characteristics curve analysis and a binary logistic regression analysis suggested that the PL and CE tasks (but not the VSSP tasks) were relevant variables for identifying children with DD. Hierarchical linear regression analyses showed that the PL and CE (Backward Digit Span only) tasks were significant predictors of reading and spelling abilities.