Language comprehension in children, adolescents, and adults with Down syndrome.

BACKGROUND: There is conflicting evidence as to whether receptive language abilities of individuals with Down syndrome (DS) continue to improve into adulthood, reach a plateau in late adolescence, or even start to decline.

AIM: The study aims to shed light on the question whether receptive syntactic skills change from childhood/adolescence to adulthood and provides a detailed qualitative analysis of the receptive abilities of adults with DS.

METHODS: 58 individuals with DS participated in the study: 31 children/adolescents (aged: 4;6-19;0 years) and 27 adults (aged: 20;8-40;3 years). They completed measures of grammar comprehension, nonverbal cognition, and phonological working memory.

RESULTS: There was no significant correlation between comprehension performance and chronological age in the overall sample. Separate correlational analyses for the subgroups of children/adolescents and adults yielded a significant positive result for the former subgroup but not for the latter. We also found significant positive correlations between grammar comprehension scores and nonverbal mental age as well as measures of phonological working memory. Qualitative analyses showed various limitations in the receptive syntactic abilities of adults with DS. Difficulties increase with sentence length and grammatical complexity, but are also apparent in simple sentences.

CONCLUSION: The results suggest that syntactic comprehension abilities of individuals with DS continue to improve through childhood and adolescence and that thereafter a plateau is reached and maintained. Language comprehension in adults with DS is impaired for a variety of grammatical structures and receptive performance seems to be related to nonverbal cognitive abilities, phonological working memory, and grammatical complexity.