"There are two incontestable facts with brain-training,” says Stafford. “First, humans are amazing at getting better at anything they practice. We’re the learning species – if you want to learn pi to a hundred digits in a weekend, or to memorise a deck of cards or master Ancient Greek, you can. Second, it’s very hard to show that when you practice one thing you get better at another. The problem with all this brain-training stuff is that you might get better at doing puzzles, or remembering number sequences, but no one has found the Holy Grail of brain-training – ‘far transfer’, where you practice one thing and get better at an array of very different things."

Can you really train your brain? -
Features, Gadgets & Tech - The Independent