Does the Dynamic Testing of Working Memory Predict Growth in Nonword Fluency and Vocabulary in Children With Reading Disabilities?

This three-year longitudinal study assessed whether working memory (WM performance) when tested under dynamic testing conditions is related to growth on measures of phonological awareness and vocabulary in skilled readers and subgroups of children with reading disabilities (RD) (children with RD-only, children with both reading and arithmetic deficits, and low verbal IQ readers). A battery of memory and reading measures was administered to 78 children (11.6 yrs) across three testing waves spaced one year apart. WM tasks were presented under initial, gain, and maintenance testing conditions. The important results were (1) growth curve modeling showed that WM performance administered under initial and maintenance testing conditions was a significant moderator of growth in receptive vocabulary, whereas the number of probes and WM performance under gain testing conditions were significant moderators of growth in nonword fluency and (2) WM performance was statistically comparable within subgroups of children with RD, but inferior to skilled readers across all testing conditions. The results support the notion that children's WM performance when measured under dynamic testing conditions was related to the rate of growth on basic reading and vocabulary measures.