Trained in environmental health and epidemiology, Dr. James has focused his research on estimating the influence of spatial factors, including exposure to nature, the built environment, the food environment, air pollution, light pollution, noise, and socioeconomic factors, on health behaviors, mental health, aging, and chronic disease within large prospective cohort studies. He has developed methodologies link smartphone-based global positioning systems (GPS) and wearable device accelerometry data to understand how spatial factors influence health behaviors. He has also created novel metrics of spatial factors by applying deep learning algorithms to nationwide street-view images.