*2.2. Materials and Procedure*

Infants took part in two tasks: (1) the visual attention task, and (2) the audiovisual task. First, infants were tested in the visual attention task, followed by the audiovisual task. After completing both tasks, parents provided information on demographic and health status of the infant. Overall communicative development was assessed with the Communicative and Symbolic Behavior Scales Developmental Profile (CSBS-DP) adapted for Portuguese, that measures infants and toddlers' development from 6 to 24 months of age [37]. The CSBS-DP provides data on several scales: emotion and use of eye gaze, use of communication, use of gestures, use of sounds, use of words, understanding of words, and use of objects.
