Professor Easton joined the department in 1974. He specializes in the relationship between different perceptual systems. One major program of research focuses on the extent to which perceptual systems can share information, especially at the presemantic level where modularity of the systems is thought to be the primary architecture. Another major program of research explores sensory substitution in visually impaired people, in particular the ability of the auditory and somatosensory systems to convey information typically garnered by the visual system. Major funding for the sensory substitution work for the past twenty years has been provided by The National Eye Institute.