Characteristics of maternal input to children with Down syndrome: A comparison with vocabulary size and chronological age-matched groups

The lexical and structural characteristics of the maternal input addressed to 24-month-old children with Down syndrome were compared to the input addressed to two groups of typically developing children; matched for chronological age (CA Group) and lexical skills (Vocabulary Group), respectively. The aim of the study was to verify whether the characteristics of the language addressed to children with Down syndrome are oversimplified, as found in previous studies, or if they are appropriate for the children's developmental level. Data analyses show that the lexicon directed towards these children is simpler than that addressed to both of the comparison groups in terms of vocabulary composition (fewer function words and more onomatopoeic words/routines) and simpler than that addressed to the CA Group in terms of lexical variability. However, in terms of syntactic complexity, the input is mid-way between the two comparison groups. In addition, the analysis of maternal imitative utterances shows that the children with Down syndrome receive a lower proportion of imitative utterances than could be expected based on their age.