Disrupted behaviour in grammatical morphology in French speakers with autism spectrum disorders.

Mixed and inconsistent findings have been reported across languages concerning grammatical morphology in speakers with Autism Spectrum Disorders (ASD). Some researchers argue for a selective sparing of grammar whereas others claim to have identified grammatical deficits. The present study aimed to investigate this issue in 26 participants with ASD speaking European French who were matched on age, gender and SES to 26 participants with typical development (TD). The groups were compared regarding their productivity and accuracy of syntactic and agreement categories using the French MOR part-of-speech tagger available from the CHILDES. The groups significantly differed in productivity with respect to nouns, adjectives, determiners, prepositions and gender markers. Error analysis revealed that ASD speakers exhibited a disrupted behaviour in grammatical morphology. They made gender, tense and preposition errors and they omitted determiners and pronouns in nominal and verbal contexts. ASD speakers may have a reduced sensitivity to perceiving and processing the distributional structure of syntactic categories when producing grammatical morphemes and agreement categories. The theoretical and cross-linguistic implications of these findings are discussed.