Article choice in children with High Functioning Autism (HFA) and in children with Specific Language Impairment (SLI).

This study reports on the choice between a definite and an indefinite article by children with High Functioning Autism (HFA) and children with Specific Language Impairment (SLI). We carried out an elicited production task with 16 Dutch-speaking non-grammatically impaired children with HFA aged 6-13, 16 age-matched Dutch-speaking children with SLI, and 16 typically developing (TD) age controls. The results in the indefinite conditions reveal virtually no errors across groups. However, in the definite condition the HFA group, but NOT the SLI group, incorrectly produces indefinite articles significantly more often than the TD group. A more detailed analysis shows that 38% (6/16) of the children with HFA vs. 13% (2/16) of the children with SLI regularly produce indefinite articles in definite contexts. We propose that these children do not always calculate the additional (pragmatic) meaning of indefinites derived by scalar implicature (Horn 2006). Furthermore, development by age in the SLI group, but NOT in the HFA group, suggests that the failure to draw a scalar implicature is more persistent in children with HFA than in children with SLI. Concluding, our results show that non-grammatically impaired children with HFA are more prone to pragmatic impairments than children with SLI, suggesting a dissociation between grammar and pragmatics