Linguistic and other cognitive abilities in children with Specific Language Impairment as compared to children with High-Functioning Autism

This study investigates the question as to whether and how the linguistic and other cognitive abilities of children with Specific Language Impairment (SLI) differ from those of children with High-Functioning Autism (HFA). To this end, 27 Dutch-speaking elementary-school-age children with SLI, 27 age-matched children with HFA, and a control group of 27 age-matched Typically Developing (TD) children were experimentally tested on various components of grammar, pragmatics, and nonverbal cognition. Prima facie, the results suggest a resemblance between SLI and HFA in their lower-than-TD performance on pragmatics. However, the children with SLI perform significantly weaker than the TD children on grammar and several cognition tests, while the children with HFA do not. It is concluded that, despite their initial resemblance in terms of pragmatics, children with SLI have profoundly different profiles from children with HFA in terms of grammar and nonverbal cognition and can thus not be considered as instantiations of the same continuum, as proposed by Bishop (2010).