title: Domain-specific cognitive systems: insight from Grammatical-SLI.
abstract: Specific language-impairment (SLI) is a disorder of language acquisition in children who otherwise appear to be normally developing. Controversy surrounds whether SLI results from impairment to a "domain-specific" system devoted to language itself or from some more "domain-general" system. I compare these two views of SLI, and focus on three components of grammar that are good candidates for domain-specificity: syntax, morphology and phonology. I argue that the disorder is heterogeneous, and that deficits of different subgroups potentially stem from different underlying causes. Interestingly, although poor sensory or non-verbal abilities often co-occur with SLI, there is no evidence that these impairments cause the grammatical deficits found in SLI. Moreover, evidence suggests that impairment in at least one subgroup is specific to grammar.
authors.affiliation: Centre for Developmental Language Disorders & Cognitive Neuroscience, Department of Human Communication Science, University College London, 2 Wakefield Street, London WC1E 1PF, UK. h.vanderlely@ucl.ac.uk
authors.forename: Heather K J
authors.initials: HK
authors.lastname: van der Lely
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000145:classification* / Q000503:physiopathology*; D006801:Humans; D007802:Language; D007805:Language Development Disorders / Q000145:classification* / Q000503:physiopathology*; D010641:Phenotype