How do we sort the objects, people, events and ideas in the world into their proper categories? What transforms the 'blooming, buzzing confusion' that enters our eyes and ears when we are born into the orderly world which we eventually experience and interact with? This most basic of questions about human (and animal) perception and cognition is the subject of Categorical Perception, an exhaustive survey and integration of a diverse array of findings. Categorical Perception brings together all the known examples of categorical perception, from research on humans and animals, infants and adults, in all the sense modalities: hearing, seeing and touch. The perceptual findings are interpreted in terms of the available cognitive and neuroscientific theories of how categorical perception is accomplished by the brain: is it inborn? is it learned? what is it that the mind does to the incoming continuous information to sort it into the discrete categories we can see, manipulate, name and describe? Work on elementary perceptual and psychophysical categories (colours, sounds) is then compared with work on higher-order categories: objects, patterns, abstract concepts. From a focus on the most thoroughly investigated case of categorical perception - speech perception - the book proceeds to an integrative view of categorization in general.