Aphasia, a devastating disorder resulting from stroke, degenerative disease, or traumatic brain injury, profoundly affects the individual's ability to use and understand language. This groundbreaking work brings together an array of leading scientist-practitioners to review what is known about aphasia and to relate current knowledge to treatment. Integrating traditional linguistic formulations with new insights derived from cognitive neuroscience, the volume explores the neuropsychological bases of both normal and pathologic language. Chapters address the major domains of language impairment in aphasia and also consider such related disorders as apraxia of speech, alexia, agraphia, and limb apraxia. Major principles of rehabilitation are described and evaluated, and the treatment literature is reviewed in depth. Throughout, the volume reflects a sophisticated understanding of brain structure and function based on new developments in connectionist modeling and functional neuroimaging.