Stephen W. Porges, PhD, is a professor of psychiatry and the director of the Brain-Body Center at the University of Illinois at Chicago. He is a former president of the Society for Psychological Research and also the Federation of Behavioral, Psychological, and Cognitive Sciences. He is a former recipient of a National Institute of Mental Health Research Scientist Development Award. He has published more than 200 peer-reviewed scientific papers across several disciplines including anesthesiology, critical care medicine, ergonomics, exercise physiology, gerontology, neurology, obstetrics, pediatrics, psychiatry, psychology, space medicine, and substance abuse. His research has been cited in several thousand peer-reviewed articles and has been continuously funded by the National Institutes of Health since 1975. In 1994 he proposed the Polyvagal Theory, a theory that links the evolution of the vertebrate autonomic nervous system to the emergence of social behavior. The Polyvagal Theory provides a theoretical perspective to study and to treat stress and trauma. See: StephenPorges.com.