Allan J. Hamilton, MD, is a Harvard-trained brain surgeon, a renowned horse trainer, a developer of equine-assisted learning programs, and the author of Lead with Your Heart and Zen Mind, Zen Horse (Gold Nautilus Award winner). He is a professor of neurosurgery at the University of Arizona and a medical script consultant for the hit television series Grey's Anatomy. He raises Lipizzan horses on a small ranch on the outskirts of Tucson, Arizona.