What components of working memory are associated with children's reading skills?

Working memory (WM) is a potentially important factor related to the development of and performance in reading skills. This study examined the differential relations between two components of the WM system (i.e., storage, processing) and reading. Latent variables were created based on data from 1900 children (1146 children in preschool-second grade and 754 children in third-fifth grade) recruited for a larger study concerning the development of reading comprehension. Results indicated that a general-specific model of WM was a good fit to the data and effectively isolated the variance unique to WM-processing from that of WM-storage. Using the general-specific model, relations between the components of WM and reading (e.g., reading comprehension, decoding) and reading-related (e.g., oral language, phonological awareness, nonverbal IQ) outcomes were examined. In contrast with previous studies that have suggested WM is consistently associated with reading comprehension, our findings indicate that both aspects of WM (i.e., storage, processing) operate primarily indirectly through foundational reading-related skills. In sum, the WM system is not specifically associated with reading comprehension as most of the effects of WM-processing are indirect via the effects on foundational reading-related skills.