Wass, S., Phillips, E., Smith, C., & Goupil, L. 2021. PsyArXiv
We currently understand little about how autonomic arousal influences early vocaldevelopment. To examine this, we used wearable microphones and autonomic sensors tocollect multimodal naturalistic datasets from 12-month-olds and their caregivers. Weobserved that, across the day, clusters of vocalisations occur during elevated infant andcaregiver arousal. This relationship is stronger in infants than caregivers:caregivers showgreater functional flexibility, and their vocal production is more influenced by the infant’sarousal than their own. Cries occur following reduced infant arousal stability and lead toincreased child-caregiver arousal coupling, and decreased infant arousal. Speech-likevocalisations also occur at elevated arousal, but lead to longer-lasting increases in arousal,and elicit more parental verbal responses. Our results suggest that vocal development is moredependent on interpersonal arousal coupling across caregiver-infant dyads than previously thought.