Is it worth going to the mind Gym?

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I'M CONCENTRATING hard, staring at a small white square in the middle of my computer screen. Any second now a letter is going to flash up inside the box. At the same time a bird will pop up elsewhere on the screen. My task is to hit the bird with my mouse, then type the letter in the box. I'm playing a game called Birdwatching, and if my boss catches me at it I'll have some explaining to do. But I've got an excuse: I'm training my brain. The more I practise, the better I'll get and the more powerful my brain will become - or at least that's what I'm told. Birdwatching is the brainchild of San Francisco-based Lumos Labs, just one of the dozens of companies that have sprung up in recent months to cash in on the "brain-training" craze. Like most of its competitors, the theory behind its sales pitch is straightforward. Your brain is like a muscle: the more you use it, the stronger it will get. For those who believe that claim, there are dozens if not hundreds of brain-boosting games now on the market, not to mention a plethora of books and magazines on the same subject. The best-known product is a video game called Dr Kawashima's Brain Age, developed by neuroscientist Ryuta Kawashima from Tohoku University in Japan; it is marketed in the UK and Australia as Brain Training: How Old Is Your Brain? and endorsed by actress Nicole Kidman. While each brain trainer makes slightly different claims, broadly speaking they offer one of two benefits. Either they will "enhance normal brain functioning" - things like attention, memory and processing speed - or they will "slow down the inevitable decline that comes with age". Practically all of the companies say that their programs are based on the latest scientific evidence. So is it worth investing in brain training, and do you risk being outsmarted if you don't? Unfortunately for the wannabe genius, there are no simple answers. While there is no shortage of studies suggesting that some cognitive functions can be trained, the link between most of these programs and a better-performing brain is still unproven. "Does brain training work? It depends," says Torkel Klingberg, a brain-training expert at the Karolinska Institute in Stockholm, Sweden. "That's like asking, 'Do drugs work?'. It depends on the molecule." Commercial brain training has been around for at least a decade, but has only really caught on in the past couple of years. According to figures published in The New York Times in November 2007, the US brain-training market was worth just $2 million in 2005 but was expected to be worth $80 million in 2007. The catalyst for this exponential increase was probably the release of Brain Age in 2005. The game runs on the Nintendo DS console and has sold more than 14 million copies worldwide. For an investment of around $20 (plus the price of the console) and a few minutes' concentration a day, it promises to help you "get the most out of your prefrontal cortex". Like its competitors, Brain Age is a collection of puzzles and video games that use cognitive skills such as memory, attention and rapid processing. As with all video games, the more you play, the better you get. What makes brain-training games special, so the story goes, is that your improvements are not just within the context of the game but manifest themselves in the real world as well. On the face of it, this makes a lot of sense. It's well known that older people who stay mentally active are more resistant to cognitive decline and dementia, and many scientific studies have backed up this "use it or lose it" hypothesis (New Scientist, 17 December 2005, p 32). So if it works for older people, shouldn't it work for everybody? Perhaps it does. Over the past 15 years or so, neuroscientists have gathered abundant evidence that important cognitive functions such as memory, attention and processing speed can be improved by training, not just in older people but in young, healthy adults too. There are also numerous studies showing that challenging a specific part of the brain encourages that region to grow and develop, as in the well-publicised example of the London taxi drivers, who develop a larger hippocampus - the part of the brain responsible for spatial memory - as they learn their way around the city (Proceedings of the National Academy of Sciences, vol 97, p 4398). Most companies offering brain training stop short of specifying how their product will physically change your brain. For evidence that brain-training programs work, they tend to point to the sheer weight of accumulated data, but dig below the surface and things start to look far from clear cut. "There's 12 to 15 years of good laboratory science that we can direct brains in a corrective direction," says Mike Merzenich, a neuroscientist at the University of California, San Francisco, who also runs a company called Posit Science, which develops "brain-fitness" programs. "Just about anything can be improved. The brain is massively plastic - if engaged in the right way." It's a key distinction: the brain certainly appears to be trainable - but you have to train it in the right way. "There's lots of confusion in the field," says Klingberg. "People say 'use it or lose it', but that doesn't mean anything unless you define 'use' and 'it'." That means that each brain-training program needs to be evaluated on its own merits. And when you do that, doubts begin to emerge. Experiments on specific programs tend to be small and poorly controlled. Unless a training program has been shown to succeed under the stringent conditions of a proper clinical trial, the results must be treated as provisional, says Merzenich. By the same token, companies' claims need to be appraised with caution. "It's an incredibly murky area," says Merzenich. "There are good studies but not many controlled trials. There's a massive level of underlying science but not much has been reduced to hard, gold-standard levels." Lumosity, created by Lumos Labs, is a typical example. According to Mike Scanlon, chief scientist at the company, the brain-training program was adapted from experiments in psychology and cognitive neuroscience literature. The company's own trials show that 30 training sessions produced significant improvements on a battery of standard tests of visual attention and working memory. This sounds impressive until you take into account the trials only involved 14 people, plus eight controls who received no contact, and that the results have not been published in a peer-reviewed journal. Lumos claims that its program trains processing speed and cognitive control, but it has yet to present evidence to back this up. This is not to say that Lumosity doesn't work or that the trials were badly designed. There's no doubt the games are fun and that you get better at them with practice. What it does suggest is that Lumosity cannot claim to be a proven route to a better brain, and that the company's results, and those of many of its competitors, need to be understood for what they are - provisional. This situation is unlikely to change, particularly as there is no incentive for companies selling brain training to conduct proper trials. As Merzenich points out, it can cost $2 million to run a controlled trial, and few companies are willing or able to shell out that kind of money. "I want to continue the research," says Scanlon, "but we're not going to keep on blowing out studies on more and more people." In any case, the brain-training market is not regulated by an FDA-like body that demands scientific proof of a product's efficacy before allowing it to be sold. Nor does a lack of clinical data seem to be a barrier to commercial success, if the growth of the US market is anything to go by. Despite a lack of large trials, Lumosity has at least been shown to make generalisable improvements: trainees not only get better at the training program itself, they also improve on independent tests of working memory and visual attention. This, says Merzenich, is one of the minimum requirements for a credible brain-training program. "It's crucial, or you're making it up," he says. Not all companies show such evidence of generalisability, however. Notable among these is Nintendo, though the company is careful not to claim that Brain Age is scientifically validated, merely stating that it is an entertainment product "inspired" by Kawashima's work. The absence of cast-iron evidence isn't necessarily seen as a problem, however. Susan Greenfield of the University of Oxford has publicly endorsed MindFit, a brain-training program for older people, on the back of research that has yet to appear in a peer-reviewed journal. She says she has seen enough evidence to convince her that brain training is worth the effort. "I believe it works," she says. "What is there to lose? There's no risk, and every chance it might be doing something." Looked at in this way, brain training is rather like an anti-ageing cream: if people want to spend their money on something that won't do them any harm and might do them some good, who's to stop them? Also like anti-ageing cream, brain-training companies are not as up front as they might be when it comes to potential limitations. Klingberg says that consumers should be more questioning. "I'm surprised that people don't care more about the science," he says, "that they don't ask, 'where's the evidence that this works?'." Like an anti-ageing cream: it won't do any harm and might do some good Against this confusing background of sales pitches and celebrity endorsement, is there any decent, independent evidence that brain training can work? Encouragingly, there is. There may not be many large-scale clinical trials, but those that have taken place all point in the same direction. In 2006, a group led by Karlene Ball of the University of Alabama, Birmingham, published the results of a huge US government-funded study of the "use i