Connectionism is a way of modeling how the brain uses streams of sensory inputs to understand the world and produce behavior, based on cognitive processes which actually occur. This book describes the principles, and their application to explaining how the brain produces speech, forms memories and recognizes faces, how intellect develops, and how it deteriorates after brain damage. The models range from some well-known classics to others at the frontiers of current research. Also included is a disk with the software for running learn, a user-friendly simulator for connectionist modeling of cognitive processes, which will run on either P.Cs. or M.A.Cs. Written by leading researchers in their field, this first up-to-date textbook on connectionist modeling, will provide an essential and accessible introduction to the field.