Cognitive processes associated with working memory in children with developmental language disorder

The current study examined how individual differences in language, nonverbal, and attention abilities relate to working memory in children with developmental language disorder (DLD) relative to age-matched typically developing (TD) peers using an interference-based model of working memory as our theoretical framework. Our experimental paradigm involved varying the domain (verbal/nonverbal) of recall items and an interference processing task, testing effects of interference. We examined the relative importance of language, nonverbal, and attention skills in predicting working memory performance by using Bayesian leave-one-out cross-validation to compare models with varied combinations of these skills as predictors. We then statistically tested selected models. Selected models were similar between groups for nonverbal, but not verbal, working memory. Language, nonverbal, and attention skills were associated with performance regardless of whether the working memory task was verbal or nonverbal for the DLD group, yet only attention was associated with verbal working memory for the TD group. A broader set of cognitive processes was involved in verbal recall in children with DLD than in TD peers, potentially reflecting diminished specialization of cognitive processes underlying language. The interference-based model of working memory accounted for interrelationships among language, processing speed, and inhibition of interference, revealing new insights into verbal processing.