Bringing models and methods of cognitive neuropsychology to bear on the study of dementing disorders, these contributions present sound evidence that diseases of the Alzheimer type compromise brain function in a highly selective manner, affecting some aspects of cognition while sparing others. Included are original case studies that explore in detail the nature of the linguistic, semantic, and visuoperceptual disorders in patients with degenerative dementias. The book pursues a number of themes with important ramifications for the study of higher mental functions. By exploring the neurocognitive modules that are the targets of degenerative processes, it shows that Alzheimer's disease is not one disease but a complex of disease states, that clinical diversity is an essential feature of Alzheimer's disease and Alzheimer-type dementia, that this diversity reflects to a large extent the differential involvement of particular neural systems that support cognition, and that when suitable methods and models are applied, studies of Alzheimer-type dementia can expand our understanding of basic brain-behavior relations.Myrna F. Schwartz is Director of the Neuropsychology Research Laboratory at Moss Rehabilitation Hospital in Philadelphia.Contributors: M. Moscovitch and C. Umilta, M. F. Schwartz, J. A. Stark, A. R. Damasio, G. W. Van Hoesen, B. T. Hyman, J. B. Chawluk, M. Grossman, J. A. Calcano-Perez, A. Alavi, H. I. Hurtig, M. Reivich, A. Martin, J. Baron, M. Moscovitch, H. Chertkow, D. Bub, E. M. Saffran, E. J. Fitzpatrick-DeSalme, H. B. Coslett.