蜜芽传媒

A common fear of growing older is what happens to our brain power. Our bodies show the signs of age on the outside - but what's going on in the inside?

For many years scientists in Edinburgh have been looking into just that, by asking a group of people who are now in their 70s, to undergo a test they first took when they were at school.

And now they say they've reached a crucial stage in their findings. As part of our series of special reports about how more of us are living longer, John Maguire's been finding out more.