Professor Nelson's research interests are broadly concerned with developmental cognitive neuroscience, an interdisciplinary field concerned with the intersection of brain and cognitive development. His specific interests are concerned with the effects of early experience on brain and behavioral development, particularly the effects of early biological insults and early psychosocial adversity. Nelson studies both typically developing children and children at risk for neurodevelopmental disorders (particularly autism), and he employs behavioral, electrophysiological (ERP), and metabolic (fNIRS and MRI) tools in his research. Over and above his domestic research program, Nelson also works in a variety of low resource countries.
A growing body of evidence indicates that children who experience significant adversity are at increased risk for lifelong programs in learning, behavior, and health. This compelling knowledge base underscores three significant, unmet needs: (1) valid and reliable biological and bio-behavioral measures (or biomarkers) of toxic stress to identify children who are at higher risk of chronic disease in adulthood; (2) more effective intervention strategies to prevent, reduce, or mitigate the long-term health consequences of significant adversity in early childhood; and (3) biomarkers that are sensitive to change and can thus be used to assess the short-term and medium-term effects of intervention strategies whose ultimate impacts on physical and mental health may not be apparent until decades later.
The proposed Research Network is committed to reducing the prevalence of lifelong health impairments caused by toxic stress in early childhood. Our approach to achieving this goal focuses on three objectives: (1) to develop a reliable, predictive panel of biomarkers (including both biological and bio-behavioral measures) that can identify children, youth, and parents showing evidence of toxic stress, and that can be collected in pediatric primary care settings; (2) to conduct basic, animal and human research on critical periods in development and individual differences in stress susceptibility, thereby informing the timing and design of a suite of new interventions that address the roots of stress-related diseases early in the life cycle; and (3) to build a strong, community-based infrastructure through which scientists, practitioners, parents, and community leaders can apply new scientific insights and innovative measures to the development of more effective interventions in the first three postnatal years.
Children with autism spectrum disorders (ASD) experience a range of social deficits that are heterogeneous and multidimensional both in their genetic underpinnings and in their phenotypic expression. Perhaps for this reason, the etiology of ASD is not well defined and the combinations of environmental and genetic factors that protect against or increase risk of developing autism are not well understood. Endophenotypes of ASD at the neural systems level may offer insight into the pathophysiology and psychopathology of ASD by indicating components of complex social behaviors that lie closer to specific genetic
factors that confer ASD risk.
This investigation focuses on the neural correlates of imitation a social function impaired in ASD in 4 to 6 year old unaffected siblings of children with ASD (US), children with ASD (ASD), age-matched typically developing peers (TD), as well as typically-developing children matched with ASD children on cognitive measures (TD-COG). In studying the neural activity and behavior of unaffected siblings of children with ASD on an imitation task, the goal is to identify and investigate neural and behavioral biomarkers of immediate clinical utility in the earlier diagnosis and prediction of ASD outcomes, as well as facilitate the design of more targeted and potentially effective interventions to increase the social functioning and improve the outcomes of children at risk for ASD.
Imitation allows children to gain an understanding of puzzling observations and communicate shared understanding (Uzgiris, 1981); it is also used in transferring cultural knowledge and learning new behaviors (Whiten, 2009). Imitation is a common means by which learning takes place in early childhood classrooms; the ability to imitate is also a hallmark of success in ASD interventions based on Applied Behavioral Analysis, which are currently considered the most effective educational treatments for individuals with ASD (Winerman, 2004). In this project, the aim is to understand whether children with ASD who imitate just as well as typically developing children show differences in the ways that they process the imitation tasks in their brains. Using a technology called functional Near-InfraRed Spectroscopy (fNIRS), which uses infrared light to track changes in blood oxygen in different parts of the brain to provide a measure of what brain regions are becoming more activated (consuming more oxygen) during certain tasks, the investigation will compare the brain patterns of children with ASD and typical children who have similar imitation scores and eyetracking patterns, to determine whether children with ASD process the same imitation tasks differently from typically developing children, at the level of their brain activity.