SLI subgroups and specialised cognitive systems
Much of our previous and current work has concentrated on identifying children and teenagers with primary grammatical disorder (G-SLI) and those with primary word-finding (vocabulary) disorder (WF-SLI), while investigating underlying causal mechanisms. The work on G-SLI has been ongoing since 1987; the focus upon WF-SLI subgroup is more recent. Our early research, which focussed upon the grammatical and non-grammatical language, and non-verbal cognitive abilities of SLI children, generated two major findings - the identification and characterization of a subgroup of SLI children with what appeared to be a specialized grammatical deficit (G-SLI); and evidence for the existence of a genetically determined, specialised mechanism which is needed for the normal development of grammar. Although still controversial, these findings along with subsequent research suggest that grammatical deficits found in (at lease some) SLI children are not a function of a general cognitive deficit. If substantiated, this conclusion has direct implications for therapy. For example, if decreasing the general cognitive load in a task is unlikely to facilitate syntactic functioning, then alternative approaches to remediation may be necessary.
