Javier DeFelipe, author of Cajal's Butterflies of the Soul (2009), is a neuroscientist at the Instituto Cajal, Madrid. Larry W. Swanson of the University of Southern California is the author of Brain Architecture (2012) and a past President of the Society for Neuroscience. Eric A. Newman, Alfonso Araque and Janet Dubinsky are distinguished neuroscientists at the University of Minnesota.