"Edu-tainment" games like the popular Brain Training series (available on the Nintendo DS console) have been credited with bringing a new group of older users to gaming. The game features a number of activities, such as solving math problems, counting currency and unscrambling letters, that Nintendo says is based on the work of Japanese neuroscientist Ryuta Kawashima.

"The Nintendo DS is a technological jewel. As a game it's fine,” Alain Lieury of the University of Rennes in Brittany, told the Times of London “But it is charlatanism to claim that it is a scientific test.”

Lieury conducted a study with 67 10-year-old children, who are at an age where he says they have the best chance of improvement in brain performance.

He split the children into four groups — two did a seven-week memory improvement course, while the other did puzzles with pencil and paper, and the last went to school as normal.

At the end of the seven-week period, all the children were given tests to measure memory, logic, arithmetic skills and symbol interpretation.

Lieury found no significant improvement in memory among the first two groups — in fact, they registered a decline. The group with paper and pencil did 33 per cent better in memory tests. The Nintendo group did 17 per cent worse.

The Nintendo group did fare better in math tests — a 19 per cent improvement — and that number was replicated in the paper-and pencil-group, while the fourth group improved 18 per cent.

Nintendo, in response, told the Daily Telegraph that it never claimed to have scientifically improved cognitive ability.

Nintendo's website, which doesn't explicitly say Brain Age improves a user's intelligence or memory, nevertheless says it features games "designed to help stimulate your brain and give it the workout it needs .…"

"The design of Brain Age is based on the premise that cognitive exercise can improve blood flow to the brain."

Lieury says doing puzzles like Sudoku or playing Scrabble would be just as effective as playing games like Brain Training. Lieury's findings will be published in Stimulate Your Neurones, a book due out later this month.