Memory and Cognitive Function in Normal Aging

Memory and cognitive function are known to decline in normal aging. This impairment is due both to inevitable biologic attrition of brain function and to intercurrent disease processes. Memory storage, speed of response, channel capacity, and Performance IQ on the Wechsler Adult Intelligence Scale tend to be most impaired; Verbal IQ and previously learned skills ("crystallized intelligence") tend to be preserved. Differences between individuals, independent of age, are often more significant than age-related losses until very advanced age. The biases of cross-sectional and longitudinal studies may exaggerate or minimize age-related differences and should be recognized.