The brain's attentional state is controlled by the neurotransmitters dopamine and noradrenalin. Dopamine encourages a persistent, goal-centred state of mind whereas noradrenalin produces an outward-looking, vigilant state. So not surprisingly, anything that raises dopamine levels can boost your powers of concentration.
One way to do this is with drugs such as amphetamines and the ADHD drug methylphenidate, better known as Ritalin. Caffeine also works. But if you prefer the drug-free approach, the best strategy is to sleep well, eat foods packed with slow-release sugars, and take lots of exercise. It also helps if you are trying to focus on something that you find interesting.
The second step is to cut down on distractions. Workplace studies have found that it takes up to 15 minutes to regain a deep state of concentration after a distraction such as a phone call.
Music can help as long as you listen to something familiar and soothing that serves primarily to drown out background noise.
clipped from: www.newscientist.com