Procedural memory and speed of grammatical processing: comparison between typically developing children and language impaired children

BACKGROUND: Procedural memory has been proposed to underlie the acquisition of a range of skills including grammar, reading, and motor skills. In developmental language disorder (DLD) it has been suggested that procedural memory problems lead to the difficulties with grammar in this group. AIMS: This study aimed to extend previous research by exploring associations between procedural memory and a range of cognitive skills, in children with and without language impairments. METHODS AND PROCEDURES: Twenty children with DLD and 20 age-matched non-language impaired children undertook tasks assessing procedural memory, grammatical processing speed, single word and nonword reading, and motor skills (as indexed by a pegboard task). OUTCOMES AND RESULTS: For the DLD group, no significant correlations between procedural memory and any of the variables were observed. The typically developing group showed a significant correlation (r=.482, p<0.05) between the measure of procedural memory and grammatical processing speed. Correlations between procedural memory and the remaining variables were all non-significant for this group. CONCLUSIONS AND IMPLICATIONS: This study provides new evidence showing that grammatical processing speed is correlated with procedural memory in typically developing children. Furthermore, results suggest that the relationship with procedural memory does not extend to reading or the types of motor skills used on a pegboard task. For the DLD group the pattern of result indicate grammatical processing, reading, and motor sequencing are not supported by procedural memory or a common memory system.