It is a feeling we all know - the moment when a light goes on in your head. In a sudden flash of inspiration, a new idea is born. Today, scientists are using some unusual techniques to try to work out how these moments of creativity - whether big, small or life-changing - come about. They have devised a series of puzzles and brainteasers to draw out our creative behaviour, while the very latest neuroimaging technology means researchers can actually peer inside our brains and witness the creative spark as it happens. What they are discovering could have the power to make every one of us more creative. Swedish voice over version of Horizon, episode 1 season 2013, originally broadcast on BBC Two 2013-03-14.