单项选择题
It is common for older people to forget things. Now an American study has found that memory starts to fail when we are young adults. People younger than thirty usually do not know that they are starting to forget information. But scientists from the University of Michigan say the loss of memory usually has already started.
Researchers say people do not observe this slow reduction in mental ability until the loss affects their everyday activities.
Denise Park is leading the new study. She directs the Center for Aging and Cognition at the Institute for Social Research at the University of Michigan. Her team has studied more than 350 men and women between the ages of twenty and ninety. The study has identified people in their middle twenties with memory problems.
She says young adults do not know that they are forgetting things because their brains have more information than they need.
But she says that people in their twenties and thirties are losing memory at the same rate as people in their sixties and seventies.
Ms. Park says people between the ages of sixty and seventy may note the decrease in their mental abilities. They begin to observe that they are having more trouble remembering and learning new information.
The study has found that older adults are more likely to remember false information as being true. For example, they remember false medical claims as being true. Younger people remember hearing the information, but they are more likely to remember that it is false.
Ms. Park is now using modern imaging equipment to study what happens in the brains of people of different ages. She is studying what parts of the brain older adults use for different activities compared to younger adults. Ms. Park says mental performance is a direct result of brain activity and brain structure. She says older people should take part in activities that keep their brain active. She hopes that future studies will identify ways to improve the operation of our aging minds.
A. in their early teens
B. in their mi-sixties
C. in their mid-twenties
D. in their early thirties