A study of people in their nineties reveals that many of them retain all their mental abilities, despite popular belief.
It's often assumed that if you live to be a hundred, you will pay the price in loss of independence and both mental and physical decline. But that's not necessarily the case, according to researchers at the Mayo Clinic.

They report from the Mayo Oldest Old Study, which looks at the mental performance of a group of 111 local people aged between 90 and 99. At least half had no sign of dementia and performed well on all cognitive tests. This group hasn't been much studied before. The researchers were interested to learn that they could detect mild cognitive impairment (MCI) in these older people and distinguish it from normal mental functioning. Those who did have MCI showed the same symptoms as younger people with this condition, which often precedes dementia.