If you train intensively at long-distance running, you’ll find it easier to climb stairs or ride a bike. The running will boost your aerobic fitness and strengthen your leg muscles, providing benefits that transfer to other activities. Does our brain work in the same way? If we train ourselves on a specific mental task, do we become sharper across the board?

There’s a multi-million dollar industry that would like you to believe the answer is yes. Best-selling “brain training” games like Brain Age purport to give your brain a “the workout it needs” through a combination of word puzzles, number problems, Su Doku and more. Unfortunately, there is little good evidence that these games improve anything beyond performance