Predicting language production in children and adolescents with Down syndrome: The role of comprehension

Predictors of language production skills in 12-minute narratives are invest igated cross-sectionally in 48 children and adolescents with Down syndrome (trisomy 21), aged 5 to 20 years, in comparison to 48 control children aged 2 to 6 years matched statistically for nonverbal mental age and mother's y ears of education. Two models were evaluated by hierarchical regression ana lyses using predictors drawn from the domains of group membership, chronolo gical age, cognition, socioeconomic status, and hearing screening status (M odel I) and, additionally, comprehension performance (Model II). Results sh owed that Model ii was more successful. In the DS group, it explained 68% o f the variability in number of different words, 80% in MLU, and 32% in inte lligibility Corresponding percent ages for the control group were 72%, 71%, and 26%. A mechanism linking comprehension of input to early stages of pro duction practice through activation of the early speech motor area is propo sed.