Mobiles and the internet have opened up the world, only to shrink our horizon to 2in. They may even be affecting the way we think – and not necessarily for the better.

Researchers at the University of Illinois have shown that if people who are engaged on a challenging task are interrupted by a call or an e-mail, they can take up to 15 minutes to refocus on their original purpose. Other studies have shown, perhaps unsurprisingly, that interruptions impair creativity and memory.

Researchers have found that if you react to a call or message at a natural break-point in your existing work, you are much better at assimilating the information and returning to your previous task. But if you cannot resist answering your Crack-Berry as soon as it rings, you are likely to suffer “distraction overload”.