Nouns and predicates comprehension and production in children with Down syndrome.

Our study investigated the lexical comprehension and production abilities as well as gestural production taking into account different lexical categories, namely nouns and predicates. Fourteen children with DS (34 months of developmental age) and a comparison group of 14 typically developing children (TD) matched for gender and developmental age were assessed through a test of lexical comprehension and production (PiNG) and the Italian MB-CDI. Children with DS showed a general weakness in lexical comprehension and production that appeared more evident when the lexicon was assessed through a structured test such as the PiNG that requires general cognitive skills that are impaired in children with DS. As for the composition of the lexical repertoire, for both groups of children, nouns are understood and produced in higher percentages compared to predicates. Children with DS produced more representational gestures than TD children in the comprehension tasks and above all with predicates; on the contrary, both groups of children exhibited the same number of gestures on the MB-CDI and during the subtests of PiNG production. Children with DS produced more unimodal gestural answers than the control group. Theoretical implications of these results are discussed.