Procedural and declarative memory in children with and without specific language impairment

BACKGROUND: Much evidence has accumulated to indicate memory deficits in children with specific language impairment. However, most research has focused on working memory impairments in these children. Less is known about the functioning of other memory systems in this population. AIMS: This study examined procedural and declarative memory in young children with and without specific language impairment. METHODS & PROCEDURES: A total of 15 children with specific language impairment and 15 non-impaired children of comparable age, gender and handedness were presented with measures of procedural and declarative memory. Procedural memory was assessed using a Serial Reaction Time (SRT) Task in which children implicitly learnt a ten-item sequence pattern. Declarative memory for verbal and visual information was assessed using paired associative learning tasks. OUTCOMES & RESULTS: The results from the SRT Task showed the children with specific language impairment did not learn the sequence at levels comparable with the non-impaired children. On the measures of declarative memory, differences between the groups were observed on the verbal but not the visual task. The differences on the verbal declarative memory task were found after statistically controlling for differences in vocabulary and phonological short-term memory. CONCLUSIONS & IMPLICATIONS: The results were interpreted to suggest an uneven profile of memory functioning in specific language impairment. On measures of declarative memory, specific language impairment appears to be associated with difficulties learning verbal information. At the same time, procedural memory is also appears to be impaired. Collectively, this study indicates multiple memory impairments in specific language impairment.