Word Retrieval Difficulties and Cognitive Control in Specific Language Impairment.

Abstract

Purpose The study aims to test whether children with specific language impairment (SLI) show weaknesses in word retrieval and cognitive control and to find out whether impairments in the 2 domains are associated. Method Thirty-one children with SLI (age: M = 8;11 years;months, SD = 1;1) and 31 age- and IQ-matched typically developing children completed 2 word retrieval tasks and 3 cognitive control tasks. Word retrieval was assessed with a fluency task and a rapid automatized naming (RAN) task, whereas cognitive control was measured with a backward digit span, an n-back task, and a Stroop task. Results We found weaker performance in the SLI group than in the typically developing group in all the fluency conditions and in the size-color-shape RAN as well as on the backward digit span and n-back tasks. Performance on the letter fluency task was associated with backward digit span, whereas size-color-shape RAN performance was associated with backward digit span and n-back scores. Testing the relative contribution of the 3 cognitive control tasks together with verbal short-term memory span and vocabulary size showed that performance on both word retrieval tasks was best explained by nonword repetition and backward digit span measures. Conclusions These results suggest that both word retrieval and cognitive control are impaired in SLI and weaker cognitive control may contribute to word retrieval problems, although weaker short-term memory also has a crucial contribution to word retrieval difficulties during these tasks. If further research confirms this association with cognitive control, training of this ability should be included in the therapy of at least some children with SLI.