The answer I gave was that while there does appear to be some support for the notion that cognitive exercise can help maintain cognitive capacity and what neuroscientists call 'cognitive reserve', I am not aware of any hard evidence to support the claims of the brain game manufacturers.
The best piece of research I could find on the subject was a study by the consumer watchdog Which? in 2009, where they looked at the validity of the claims made by products such as Dr Kawashima's Brain Training. Coincidentally, I had one bought for me by my children as a Christmas present, but stopped using it after it said I had the brain of an 83 year old!
Which? began by asking the manufacturers what the benefits of using their products were and to back their claims up with evidence. They sent this to three experts and asked if they thought the evidence justified the claims. They looked at whether the evidence related directly to the product concerned and whether it had been checked by experts working in the same field and published in a reputable scientific journal.As an example, one manufacturer claimed that “in just 20 minutes a day, the CD will help increase thinking ability, prevent brain aging, and hone memory, language, concentration, visual/spatial skills and executive function.”
One of Nintendo’s claims was that playing the game helps improve blood flow to the frontal cortex and thereby improve "practical intelligence". But the three neuroscientists consulted by Which? said there was no evidence that an increased blood flow had "any functional impact on your life whatsoever."Which? Editor Martyn Hocking said: "If people enjoy using these games, then they should continue to do so - that's a no-brainer. But if people are under the illusion that these devices are scientifically proven to keep their minds in shape, they need to think again."