Recent international reports emphasize that the first three years of children’s life have more impact on their future outcomes than any other period during life. It is therefore essential that we have a thorough understanding of early social and cognitive development. In the past, experimental research that has fed our knowledge on early development studied infants within restricted, artificial laboratory contexts. However, only by studying children who are actively engaging in natural interaction with their social and physical environment, we can acquire ecologically valid, robust information about their social and cognitive development. It is thus essential to move experimental infancy research towards more natural situations. In doing so, MOTION will train a new generation of highly-skilled experts in the field of early development. New advances in wearable and wireless technologies now provide us with a unique opportunity. We are able to literally "unleash" the children we study – to free them from cables and constraints associated with the previous research methods. The primary scientific aim of the MOTION project thus is to leverage these new technological advances to study infants’ and toddlers’ body movements, gaze direction, and brain activity as they spontaneously and actively explore the world around them. MOTION will develop, produce and commercialize new tools to study early development in close cooperation between industry and academic partners. Innovative research tools will be used to investigate infants in natural interaction with their social and physical environment and gain a deeper understanding of early development. In addition to disseminating the new tools and research findings among the scientific community, it is the explicit aim of MOTION to reach out to professionals and the public, educate them about early development and instigate an open dialogue between professionals working with young children and developmental researchers.

The first three years of life are critical for children’s long-term development, health and wellbeing, since core brain functions are formed during this period and the brain is much more vulnerable to adversity, which is key for the emergence of developmental disorders (autism, attention deficit/hyperactivity disorder). Identifying the mechanisms that act during early childhood to shape individual long-term social development is essential for improving the health and wellbeing and has far-reaching consequences for social and educational policy. We propose that this key scientific problem cannot be solved without first understanding how early social exchanges tune critical brain functions in early childhood. Daily, repeated exchanges between infants and caregivers provide the substrate for the interacting influences of genes and the environment on brain development. By studying the micro-scale dynamics of early social exchanges we can revolutionise the understanding of macro-scale development of socially-relevant functions like theory of mind, language, attention, and emotion regulation. Our radically new approach puts social exchanges at the heart of brain development, which is sculpted through a complex ongoing cascade of interactions between the brain and its social environment. SAPIENS combines advances in ecological, mobile real-time brain and behaviour measurement, data modelling and artificial intelligence approaches to train a new generation of researchers in implementing these ground-breaking approaches to early social development. SAPIENS will generate revolutionary new tools for translating cutting-edge basic science into clinical diagnostic and treatment tools for developmental disorders, while engaging the public and delivering new public policy. By building on a strong intersectorial network of excellent research centres and industry, we will provide highly innovative and multidisciplinary training for young research leaders in developmental science.