AGEING is a daunting process, not least because some of the first things to fail are also the most useful, such as memory, attention and motor skills. The idea that some form of regular mental activity—doing a crossword, for example—can postpone mental decline is not new. Now researchers have found another: playing a certain type of video game could help the elderly stay sharper for longer.

Video games can be fun but whether they serve any useful purpose beyond keeping some young people confined to their bedrooms is questionable. In a 2010 study thousands of volunteers spent six weeks playing video games but showed virtually no improvement in performance of cognitive tasks that were not related to the game when compared with non-players. The players’ gaming skills improved, but the prowess did not extend to other cognitive areas.

Age, though, was not a factor in this study: most of the participants were in their late 30s or early 40s. So things might be different for other age groups. Adam Gazzaley of the University of California, San Francisco, and his colleagues wondered if playing video games would be more effective in exercising the brains of older people. And, according to their research just published in Nature, that turns out to be so.

Dr Gazzaley and his team recruited more than 200 volunteers, whose ages spanned seven decades, to play a video game designed specially to use multi-tasking skills, which can be particularly testing for older folk. The participants, who had healthy vision and little prior gaming experience, used a hand-held controller to drive a car following a line on a road. At the same time they had to pay attention to signs that would appear above the car. As they played the game, the brain activity of each participant was measured by a cap fitted with electrodes.

The first set of experiments, which involved those aged between 20 and 79, found, not surprisingly, that the older participants had to put more mental effort, as measured by their brain activity, into the game than younger people. In other words, they found multi-tasking harder.

In the second set of experiments, a group aged 60 to 85 got to take the video game home and play it in an adaptive mode (as they got better at the game, the game got harder) for three hours a week over a month. When the participants returned, their multi-tasking abilities were again measured with the cap and found to have improved along with other aspects of cognition that were not specifically demanded by the game, such as working memory. The improvement in multi-tasking was so great that the amount of cognitive effort required by the oldies after their training was no more than if they were in their 20s and playing the game for the first time. Furthermore, the changes seemed to last for some time. After a six-month break from playing, the older participants were still nimble-minded.

Exactly how the process works neurologically is still an open question. The prefrontal cortex, a region of the brain responsible for attention, is one area being explored by researchers. In the meantime, the gaming and brain-training industry might find new customers. With more disposable income, free time and discipline to play games in moderation, older people could be a healthy market for a whole new generation of video games.