This project involved an investigation of executive functioning (EF) abilities in children with specific language impairment (SLI). SLI is a common neurodevelopmental disorder marked by language delays that are out of line with a child's other abilities. Executive functioning refers to the higher-order cognitive skills required for novel tasks with no well-learned patterns of responding. Recent theoretical approaches have suggested that brain regions implicated in EF show abnormalities in children with SLI. Therefore, the aim of this research is to provide a thorough investigation of a broad range of their EF skills. There are two important messages from our findings: A range of verbal and non-verbal EF abilities in children with SLI were below those of typical children after controlling for differences in age as well as verbal and non-verbal IQ. As predicted by Ullman' (2004) declarative/procedural model, EF abilities were more closely related to grammar than vocabulary, a finding that occurred in both the SLI and typical groups. Together these findings suggest that children with SLI have a broader range of cognitive difficulties than is often appreciated; and this has implications for our conceptualisation of the disability and for intervention.

A large battery of screening tests (IQ, language, working memory) and experimental tests of executive functioning (inhibition, executive-loaded working memory, fluency, planning and switching) was administered to 120 individual children. 40 children in the sample were diagnosed with specific language impairment; 40 comprised a comparison group of typically developing children matched for language age; and 40 comprised a comparison group of typically developing children matched for chronological age. All participants came from schools in Greater London and were recruited via contacting Head Teachers or Speech and Language Therapists.