All those hours spent on your DS crunching numbers and memorising words on a brain training game, may well have amounted to nothing if a recent report is to be believed.

Researchers at the University of Rennes in Brittany have concluded that there is no evidence that supports Nintendo's claims that popular games such as Dr Kawashima's Brain Training do anything to improve your mental sharpness.

Games such as Brain Training and Big Brain Academy have been said to improve "practical intelligence" and will help regular users to perform "two or three times better" in memory tests.

However, in tests run on 67 10-year-old children, it was found that those who undertook a seven-week memory course using the DS failed to show any significant improvements in memory tests compared to those children who did puzzles on paper, or did nothing outside of regular homework.

"If it doesn’t work on children, it won’t work on adults", said Alan Lieury, professor of cognitive psychology at the University of Rennes.

He added: "As a game it’s fine, but it is charlatanism to claim that it is a scientific test".

Brain training games have been a smash hit with consumers since their launch, and have played a big part in opening up the market of the Nintendo DS to a new, slightly older audience.

However, Nintendo has hit back in defence of such titles, saying it never claimed the games were scientifically proven to improve memory.

"The challenges in Brain Training and More Brain Training are inspired by the exercises developed by respected neurologist Dr Kawashima, who believes that the brain needs to be exercised to help stay fit in the same way that our bodies need exercise to stay in shape", said a Nintendo spokesperson.

"The game requires users to perform a number of fun challenges incorporating simple arithmetic, memorisation and reading. In this way it is like a workout for the brain and the challenges in the game can help stimulate the player’s memory".