The procedural learning deficit hypothesis of language learning disorders: we see some problems

Impaired procedural learning has been suggested as a possible cause of developmental dyslexia and specific language impairment (Nicholson & Fawcett, 2007; Ullman & Pierpont, 2005). However, studies investigating this hypothesis have delivered inconsistent results to date. These studies typically use extreme group designs, frequently with small sample sizes, and measures of procedural learning with unreported reliability.

We will first summarize the findings from our recent meta-analysis of studies in this area and then present the results of two studies that used a concurrent correlational design with large samples of children to examine the relationship between procedural and declarative learning and language-related attainment. The results of these two studies provide no support for the procedural deficit account of language learning disorders and highlight the importance of establishing the reliability of procedural learning measures used to investigate the procedural deficit hypothesis.