Early Perception of Intonation in Down Syndrome: Implications for Language Intervention

Language difficulties have been highlighted as a cornerstone of the developmental profile in Down Syndrome (DS), but very few studies have examined early language abilities in children with DS to determine the initial strengths and weaknesses that might inform early language interventions to support language development in this population. This study focused on the early perception of intonation and examined whether it differed between infants with DS and typically developing (TD) peers. Using a visual habituation paradigm from a previous study on TD infants' ability to perceive the intonation of statements and questions, infants with DS were able to successfully discriminate statement and question intonation, similarly to TD infants. However, unlike for TD infants, an age group effect was found, with older infants with DS being unable to discriminate the intonation contrast. Our findings highlight the importance of prosody in early development also in infants with DS. Moreover, the unexpected decrease in early sensitivity to intonation in older infants with DS pinpoints a crucial developmental window-the first semester of life-for early interventions using intonation to support language learning in these infants.