An Irish scientist and his team of researchers have discovered how some old people stay sharp and smart.

Dr John Foxe graduated from University College Dublin and is now leading a research team at at the Nathan Kline Research Institute in Orangeburg, New York.

Speaking to the Irish Times, Dr Foxe said he wanted to find out what was "special" about the elderly that were as "sharp as a tack."

"With older people you get a lot of variance. Some get doddery but with others you say, ‘He is as good as he ever was," said Dr Foxe.
Dr Foxe and his colleague, Dr Pierfilippo De Sanctis, assumed that the brains of sharper pensioners remained youthful and escaped deterioration with age or else some elderly brains were able to reorganize and deal with ageing.
The researchers studied the brain wave activity (EEG) of groups of people with an average age of 75.
Each subject was asked to do two tasks at the same time. The tasks included mathematical and alphabetical tasks. The subjects were asked to switch back and forth between these tasks. 

Dr Foxe said that many old people found it difficult to switch between tasks.

"You can switch your attention around easily, but the elderly have a problem with this. Using EEG we could watch the brain switch between these tasks.”

Dr Foxe soon realized that though the sharper subject’s brains were aged, they had been able to overcome difficulties by making fresh use of the frontal lobes.

“What we found was their brains had been substantially reorganized. What they had been able to do is compensate by reorganizing,” added the Irishman.
 Dr Foxe was hopeful that other people could learn to make better use of their frontal lobes as they age.
“If these folks can learn the trick, then we may be able to find how to teach others to do it. What is good about this is we can objectively measure this. We can see if we can take people in the lower-performing bracket and move them up to a higher bracket.”