Communicative signals drive neural expectations for non-human agents in 4-month-old infants

Previous works found that variability in the exchanged signal sequences in a turn-taking interaction indicates information transfer as opposed to the exchange of identical signals, and induces preverbal infants to attribute communicative agency to the interacting entities. Additionally, faces preceded by infant-directed speech elicit a stronger face-specific N290 ERP response in 4-month-olds, suggesting that communicative signals generate the expectation of a communicative partner and facilitate the processing of its features. In the present study we are investigating whether 4-month-olds attribute communicative agency to novel, non-human agents and whether such attribution facilitates the anticipation and the processing of the agent's physical appearance - as indexed by the P1 and Nc ERP components. In the warm-up phase, we familiarise infants with two visually distinguishable dyads of unfamiliar entities, one dyad that engages in a turn-taking exchange of variable signals (communicative condition), and one that exchanges identical signals (non-communicative condition). In the test phase, we measure ERPs in response to pictures of either the communicative or the non-communicative entities, preceded by the congruent sound signals. In a preliminary analysis (N=13, mean age = 139 days), we observe an enhanced P1effect (100-200 ms after stimulus onset) in response to the communicative entity, and an enhanced Nc effect (500-700 ms after onset) in response to the non-communicative entity. These results suggest that 4-month-olds' process communicative and non-communicative entities differently, as the anticipation of a communicative agent facilitates the early processing of the agent’s features, while non-communicative entities are allocated greater attention at later stages.