The public will be invited to take part in a mass brain training study later as part of a project between the BBC and medical research bodies.
A host of celebrities will kick off the experiment on the BBC science series Bang Goes the Theory at 1930BST.
People are being asked to take part in regular memory and reasoning tests to see if they can boost brain function.
Dementia experts believe such computer tests could help ward off and slow the development of the disease.
But, to date, evidence has been mixed on the effectiveness of so-called brain training.
Dementia is caused by the mass loss of cells in the brain, and some believe one way to guard against it is to build up as many connections between cells as possible by being mentally active throughout life.
The theory has prompted several firms to market brain training programmes, but a recent investigation by consumer group Which? found only “weak” evidence they worked.
However, King’s College London research has shown that keeping the mind active though things such as work or computer use, especially later in life, could help.
The BBC now wants to put brain training to the test by asking the British public to take part in the nine-month study, Brain Test Britain.
Participants will carry out 10-minute online brain training exercises three times a week for at least six weeks. Before and after the study they will be tested to see if they have improved brain function.
The trial will be launched on the BBC One show by radio presenter Evan Davis and celebrities including Richard McCourt, of Dick and Dom, and TV astrologer Russell Grant.
Tests
Mr McCourt said: “I always wondered if any of these brain training gadgets and games really work.
“I’m looking forward to being trained and finding out a lot more about how our brains function.
“The more we know about the brain, the nearer we’ll come to finding a cure for dementia – and that’s the reason why I want to be involved.”
A one-off show will be aired next year revealing the results, which will then be used by bodies such as the Medical Research Council and the Alzheimer’s Society.
Around 700,000 people in the UK currently have dementia and experts have estimated that by 2051, the number could stand at 1.7m.
The Alzheimer’s Society said even if brain function does improve through using the tests, there would still need to be a long-term study into whether this improved brain function could help protect people against the disease.
But Professor Clive Ballard, director of research at the charity, said the mass study could help solve “one of the biggest mysteries of the brain”.
“It’s vital we understand the truth behind the old saying use it or lose it.
“Every week thousands of people spend time exercising their brain using some form of computer-based brain training, but the jury’s still out on whether exercising your brain can boost your brain power.”
Sources: http://news.bbc.co.uk
