Later learning stages in procedural memory are impaired in children with Specific Language Impairment

Background: According to the Procedural Deficit Hypothesis (PDH), difficulties in the procedural memory system may contribute to the language difficulties encountered by children with Specific Language Impairment (SLI). Most studies investigating the PDH have used the sequence learning paradigm; however these studies have principally focused on initial sequence learning in a single practice session. Aims: The present study sought to extend these investigations by assessing the consolidation stage and longer-term retention of implicit sequence-specific knowledge in 42 children with or without SLI. Methods and procedures: Both groups of children completed a serial reaction time task and were tested 24 h and one week after practice. Outcomes and results: Results showed that children with SLI succeeded as well as children with typical development (TD) in the early acquisition stage of the sequence learning task. However, as training blocks progressed, only TD children improved their sequence knowledge while children with SLI did not appear to evolve any more. Moreover, children with SLI showed a lack of the consolidation gains in sequence knowledge displayed by the TD children. Conclusions and implications: Overall, these results were in line with the predictions of the PDH and suggest that later learning stages in procedural memory are impaired in SLI. (C) 2015 Elsevier Ltd. All rights reserved.