Abstract
Purpose: This longitudinal study examined differences in the development of working memory (WM) between children with specific language impairment (SLI) and typically developing (TD) children. Further, it explored to what extent language at ages 7-8 years could be predicted by measures of language and/or WM at ages 4-5 years. Method: Thirty children with SLI and 33 TD children who were previously examined on measures of WM and language at ages 4-5 years (T1) were reexamined at ages 7-8 years (T2). Results: The developmental course of WM was mostly similar for the two groups; only the development of the verbal storage component differed. At T1, children with SLI performed significantly below their TD peers on all components of WM (verbal storage, verbal central executive [CE], visuospatial storage, and visuospatial CE), whereas at T2, the differences for the visuospatial components were no longer significant when age and intelligence were taken into account. Hierarchical regression showed language and verbal CE at T1 to be significant predictors of language at T2, with no differences in the developmental associations between language and WM for the two groups. Conclusions: The results of this study suggest that particularly verbal CE is of importance for the acquisition of linguistic skills.
