Communicative abilities in infants with Down syndrome (DS) are delayed in comparison to typically developing (TD) infants, possibly affecting language development in DS. Little is known about what abilities might underlie poor communication and language skills in DS, such as visual attention and audiovisual speech processing. This study compares DS and TD infants between 5-7 months of age in a visual orientation task, and an audiovisual speech processing task, which assessed infants' looking pattern to communicative cues (i.e., face, eyes, mouth, and waving arm). Concurrent communicative abilities were also assessed via the CSBS-DP checklist. We observed that DS infants orient their visual attention slower than TD infants. Both groups attended more to the eyes than the mouth, and more to the face than the waving arm. However, DS infants attended less to the eyes than the background, and equally to the face and the background, suggesting their difficulty to assess linguistically relevant cues. Finally, communicative skills were related to attention to the eyes in TD, but not in DS infants. Our study showed that early attentional and audiovisual abilities are impaired in DS infants, and might underlie their communication skills, suggesting that early interventions in this population should emphasize those skills.
Keywords: Down syndrome; attention; audiovisual processing; communicative abilities in infants.