Richard E. Cytowic, M.D., MFA, a pioneering researcher in synesthesia, is Professor of Neurology at George Washington University. He is the author of Synesthesia: A Union of the Senses, The Man Who Tasted Shapes, The Neurological Side of Neuropsychology and (with David M. Eagleman) the Montaigne Medal–winner Wednesday Is Indigo Blue: Discovering the Brain of Synesthesia, all published by the MIT Press.