"A movement known as the new old age is sweeping society. The social norm for the elderly used to be passive and grim; consigned to rocking chairs, they were expected to enter physical and mental decline. Now the reverse is true. Older people have higher expectations that they will remain active and vital. As a result, the definition of old age has shifted. A survey asked a sample of baby boomers 'When does old age begin?' The average answer was 85. As expectations rise, clearly the brain must keep pace and accommodate the new old age. The old theory of the fixed and stagnant brain held that an aging brain was inevitable. Supposedly brain cells died continuously over time as a person aged, and their loss was irreversible. "Now we understand how flexible and dynamic the brain is, the inevitability of cell loss is not longer valid. In the aging process--which progresses at about 1 percent a year after the age of thi...