Computationally-derived evidence for bottom-up auditory attention in infancy: The auditory salience of caregiver speech relates to infant visual orienting during dyadic interaction.

Biologically inspired models of visual salience-rooted in the architecture of the primate visual system-offer powerful evidence that bottom-up visual attention is one mechanism used to select information from noisy environments across development. In contrast, parallel models of auditory salience remain underdeveloped and, critically, have never been applied to understand attention in early life. Here, we modelled the auditory salience in maternal speech during naturalistic dyadic interactions with 2-5-month-old infants (N = 221 in South Africa and Malawi) using two neurobiologically-informed computational models of auditory salience (Duangudom & Anderson, 2007; Kalinli & Narayanan, 2007). Then, we asked how moment-to-moment changes in salience related to infant looking towards their mother as evidence of bottom-up auditory attention in early life. Our results show that infant looking towards their mother is strongly related to maternal auditory salience, as defined by both models, and in both countries. This work provides the first evidence of bottom-up auditory attention in infancy, and suggests infants respond to changes in the salience of maternal signals to guide attention during naturalistic, dyadic interactions.