I'm interested in nature and origin of abstract conceptual knowledge, how it arises, the functional organization and response properties of the brain that underlie it, and the contributions of nature and nurture to its development. I currently examine these issues in the areas of quantitative reasoning (numerosity, object tracking, numbers, math) and psychological reasoning (mental states/theory of mind, goals, intentions, actions) with young infants, children, and adults using event-related brain potentials (ERPs), optical imaging (fNIRS), as well as behavioral measures.