Infants who will later develop autism: pathologic trajectory of infant's behaviours and changes in parents' stimulation to adapt to their infant.

<p>In this figure, we summarised early interaction between infants who will subsequently develop autism and their parents. Infants show less intersubjective behaviours and orienting towards people. Parents adapt their behaviour by using more regulation up and touching<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0061402#pone.0061402-Crown1" target="_blank">[13]</a>. Regulation Up/Down is defined as caregiver vocalisation that modulates the child's arousal and mood, to either excite (reg-up) or calm (reg-down). Regulation up is full of parentese, and this specific prosody appears to be significantly associated with the overall level of infants' responses, specifically infants' responses to parental vocalizations involving orientation towards people and receptive behaviours. At the third semester (S3), compared to typically developing children, fathers of infants who will later develop autism appear to commit themselves more and the vocalisations of fathers of children with AD are significantly associated with infant's intersubjective responses and seeking people.