This new book presents important recent research on cognitive disorders which are disturbances in the mental process related to thinking, reasoning, and judgement. They include delirium, dementia, and other cognitive disorders. Cognition includes the domains of attention, memory, language, gnosis, visuospatial function, praxis, and executive function, and is traditionally distinguished from the emotions or 'feelings'. Cognitive disorders may disturb one domain specifically, as in a selective impairment of memory (amnesia) or language (aphasia), or, more often, a combination of deficits, as in mental retardation and dementia.