Roger Wolcott Sperry was an American neuropsychologist, neurobiologist, cognitive neuroscientist, and Nobel laureate who, together with David H. Hubel and Torsten Nils Wiesel, won the 1981 Nobel Prize in Medicine for his work with split-brain research. A Review of General Psychology survey, published in 2002, ranked Sperry as the 44th most cited psychologist of the 20th century.