Human neurocognitive development: Early-stage processing, modifiers, and outcomes

Developmental disorders such as Autism Spectrum Disorder (ASD) and attention deficit/hyperactivity disorder (ADHD) are rarely diagnosed before age 3. Understanding the emergence of these disorders during the first years is critical to improving early identification and treatment options. We aim to understand how brain development over the first years of life relates to both typical and atypical developmental outcomes. To do this, we will conduct two large projects. First, we will follow infants who are more likely to develop common conditions like autism and ADHD from five months to toddlerhood (Part A). Second, we will study typically developing babies from pregnancy to early infancy (Part B). Both parts of our programme aim to: (1) find markers of how babies process sounds, sights and touch (sensory processing); (2) understand later-emerging skills like social motivation or self-regulation that can help babies compensate for any early difficulties in sensory processing; (3) understand how these factors might shape and predict later behavioural difficulties, like problems with social communication or attention and activity level. In Part A we build on our long experience in working with infants with a family member with ASD, who have a 1/5 chance of going on to a diagnosis themselves. We will further expand our work to infants with a family member with ADHD, who have a similarly heightened likelihood of receiving an ADHD diagnosis. We will also work with a new group of infants diagnosed with Neurofibromatosis 1, a genetic condition that frequently leads to a later ASD or ADHD diagnosis. We will compare the development of brain and cognitive functions in these groups to other babies who do not have a family history of a developmental disorder. All these groups of babies will take part in our study where we follow babies over five visits to our laboratory over the first three years of life. We study brain development using a variety of baby-friendly methods such as Near InfraRed Spectroscopy (NIRS - a type of light imaging), electroencephalography (EEG), eye-tracking, and parent-infant interaction. We have chosen to compare infant routes to autism and ADHD risk for several reasons. One of these is to determine how specific the early warning signs are for particular later outcomes. Another reason is that we know that these conditions quite commonly co-occur in the same children. We also work with international partners to join together to ask important questions about early signs and interventions for autism and ADHD. Birth is the single most dramatic change in environment that a brain experiences in its lifetime, yet its consequences for emerging functions remain surprisingly unknown. In Part B we will conduct a basic science study of typical development from pregnancy to age 5 months. We will look at whether individual differences in how foetuses respond to lights and sounds measured with ultrasound are maintained after birth. Further, we will ask whether or not there are dramatic changes in brain function that happen over the first weeks post-birth. Finally, we will study how infant's experiences interacting with other people in early infancy influences their brain development. Taken together, this project will provide deep insights into a vital period of human development.