Most people notice subtle changes in their cognitive abilities as they get older. It may take longer to think through a problem or make a calculation. Memory also may be affected. Older adults often report having increasing difficulty with short-term memory, such as forgetting where they left the car keys. They also may falter as they try to recall someone's name or a familiar word that is "on the tip of the tongue."

These changes occur to some degree in just about everyone, but they don't necessarily signal a serious medical condition such as Alzheimer's disease.

Along with these cognitive changes, there are physical changes that occur in the brain. The brain shrinks in size, and brain cells (neurons) in certain areas are lost or become faulty. These age-related changes are most likely responsible for some of the declines in cognitive abilities. However, the exact mechanisms for how this takes place are not entirely clear and are the subject of much current research.

Research on the neurobiology of aging is a large and growing field, which has begun to shed some light on what happens to the mental abilities of adults as they grow older. Some previously held beliefs have been shown to be incorrect. For example, aging does not entail a steady decline in mental and physical function as more and more brain cells die. Throughout life, including old age, cognitive development undergoes both gains and losses. As this growing body of research has already demonstrated, the brain is a complex organ that is both adaptable and modifiable.

What cognitive changes take place with age? Click here.
What physical changes happen to the brain? Click here.
Do the brains of men and women age differently? Click here.