Infants’ ability to engage in joint attention with others towards the end of the first year is fundamental to language acquisition and shared cognition. Despite this, our understanding of the endogenous cognitive mechanisms that drive infant attention during shared caregiver-infant interaction, and support dynamic inter-personal co-ordination is, at the moment, limited.
Traditional approaches to joint attention development centred on understanding how caregivers didactically structure infant learning through ostensive communication. More recent perspectives, however, drawing on dynamic systems views of early cognition, have emphasised the role of fast-acting, multi-level, sensorimotor processes that operate across the dyad to support joint action and social learning. Newly developed micro-analysis approaches to studying early interaction have shown that infants use sensory cues to rapidly coordinate their attention with an adult partner, and statistical regularities in these cues are thought to extend infant attention and support word learning.
To fully understand the contribution of joint interactions to early cognitive development however, we need to examine the mechanisms, endogenous to the infant, that support infant engagement and interpersonal contingency on a moment-by-moment basis. One way we can examine this is through the application of neurocognitive methods, such as electroencephalogram (EEG) recordings, to studying the dynamics of naturalistic, free-flowing interactions.
Analysing time-locked and continuous associations between infants’ neural activity, infant attention, and inter-dyadic behavioural coordination, this thesis assesses the sub-second cognitive processes that influence how infants allocate their attention during triadic caregiver-infant play.
First, neural evidence is presented to show that, whilst infants do not play a proactive role in creating episodes of mutual attention, they are sensitive to when their gaze is followed by an adult partner. Second, extended infant attention episodes are shown to be influenced, jointly, by attentional processes endogenous to the infant and reactive modulations in caregiver behaviour in response to changes in infant attention and cognitive engagement. Finally, the applicability of continuous methods to assessing speech-brain tracking by infants to their caregivers’ speech signal during naturalistic interactions is examined, and the role of behaviour-brain entrainment in creating and maintaining episodes of joint attention considered.
Discussion focusses on the contribution of the findings to our understanding of active learning processes that operate across the dyad during early interaction, and that support the development of shared cognition. Models of early language learning in the context of the findings are considered, and directions for future work put forward.