Perceptual learning in human and nonhuman animals: a search for common ground.

Perceptual learning has been extensively studied in both human and nonhuman animals, but the two lines of research have, for the most part, developed independently, addressing seemingly rather different issues by rather different methods. It has been argued, however, that analysis of the disparate phenomena studied in experiments on perceptual learning reveals that in all the studies, the essential feature is that appropriate training allows behavior to come to be controlled by the unique features, rather than by the common features, of similar stimuli. It has further been argued that experiments with nonhuman animals have established the existence of a range of learning processes that allow this to occur, and that these processes have general relevance, applying to humans as well as to animals.