Roger Newland Shepard

Roger Newland Shepard was an American cognitive scientist and author, born in 1929. Drawn early to puzzles and perceptual illusions, he went on to study psychology at Stanford University, graduating in 1951, and earned his doctorate in experimental psychology at Yale in 1955. In 1958 he joined Bell Telephone Laboratories, where he advanced from researcher to department director and developed computational methods for measuring similarity that helped establish multidimensional scaling. Shepard later taught at Harvard and then at Stanford, where his investigations into mental imagery, spatial transformations, and generalization reached across psychology, computer science, linguistics, and neuroscience.

Shepard’s research sought the principles that structure perception and thought. At Bell Labs he created the auditory illusion now known as the Shepard tone, an endlessly rising or falling scale that became a touchstone for computer music. He appeared alongside Max Mathews, Jean-Claude Risset, James Tenney, Wayne Slawson, and John Pierce on Decca’s Voice of the Computer in 1970, one of the first high-profile documents of machine-generated sound. In these projects, perceptual experiments doubled as musical compositions, showing how illusions could be treated as art. Risset extended Shepard’s tones into continuous rising and falling sweeps of sound (the Shepard–Risset glissando), while Tenney built them into For Ann (rising), demonstrating how psychological findings could open new musical forms. Shepard also showed how similarity among colors, shapes, and sounds could be mapped into geometric forms such as circles and helices, revealing structure in psychological space. His studies of mental rotation established that people reorient objects in their minds at a near-constant rate, offering the first objective measure of imagery. Through books including Mental Images and Their Transformations from 1982 and Mind Sights from 1990, he brought these ideas to wider audiences.

He was elected to the National Academy of Sciences and received the American Psychological Association’s Award for Distinguished Scientific Contributions in 1977. In 1995 he was awarded the National Medal of Science for his work on perception and cognition. In 2001 a special issue of Behavioral and Brain Sciences was dedicated to his theories. In 2006 he received the Rumelhart Prize for contributions to the theoretical foundations of human cognition. His auditory illusions entered concert repertoires through works by Jean-Claude Risset and James Tenney, affirming their place in the history of electronic music. Shepard passed away in 2022.