Cognitive Reserve: Capacity that enables an individual to cope with and/or recover from the impact of a neural injury or a psychotic episode.Prodromal Symptoms: Clinical or physiological indicators that precede the onset of disease.Cognition Disorders: Disturbances in mental processes related to learning, thinking, reasoning, and judgment.Neuropsychological Tests: Tests designed to assess neurological function associated with certain behaviors. They are used in diagnosing brain dysfunction or damage and central nervous system disorders or injury.Cognition: Intellectual or mental process whereby an organism obtains knowledge.Memory, Episodic: Type of declarative memory, consisting of personal memory in contrast to general knowledge.Aging: The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.Multilingualism: The ability to speak, read, or write several languages or many languages with some facility. Bilingualism is the most common form. (From Random House Unabridged Dictionary, 2d ed)Educational Status: Educational attainment or level of education of individuals.Intelligence: The ability to learn and to deal with new situations and to deal effectively with tasks involving abstractions.Alzheimer Disease: A degenerative disease of the BRAIN characterized by the insidious onset of DEMENTIA. Impairment of MEMORY, judgment, attention span, and problem solving skills are followed by severe APRAXIAS and a global loss of cognitive abilities. The condition primarily occurs after age 60, and is marked pathologically by severe cortical atrophy and the triad of SENILE PLAQUES; NEUROFIBRILLARY TANGLES; and NEUROPIL THREADS. (From Adams et al., Principles of Neurology, 6th ed, pp1049-57)Verbal Learning: Learning to respond verbally to a verbal stimulus cue.Atrophy: Decrease in the size of a cell, tissue, organ, or multiple organs, associated with a variety of pathological conditions such as abnormal cellular changes, ischemia, malnutrition, or hormonal changes.Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.Dementia: An acquired organic mental disorder with loss of intellectual abilities of sufficient severity to interfere with social or occupational functioning. The dysfunction is multifaceted and involves memory, behavior, personality, judgment, attention, spatial relations, language, abstract thought, and other executive functions. The intellectual decline is usually progressive, and initially spares the level of consciousness.Leisure Activities: Voluntary use of free time for activities outside the daily routine.ReadingIndividuality: Those psychological characteristics which differentiate individuals from one another.