British scientists have invented a new type of brain scanner that patients can wear on their head allowing them to move while being tested.

The device, which looks like a prop from a budget sci-fi movie or phantom of the opera, is in fact the latest thing in brain scanning.

"I think in terms of mapping brain activity, brain function, this represents a step change," said Matt Brookes, a physicist at the University of Nottingham.

Because you can do this while wearing it -- play bat and ball, or even drink a cup of tea.

It was at Nottingham University in the early 70s that the MRI was first developed. Now the wearable 'MEG' system has the potential to open a whole new field of brain scanning. The scanner records the magnetic field produced by brain activity and can show precisely where in the brain these movements are being controlled. The area of the brain shown in blue is where wrist and arm movements are controlled while playing bat and ball.

"Neuroscientists will be able to envisage a whole new world of experiments where we try to work out what a brain is doing but whilst a person is behaving naturally," Brookes said.

"For children with epilepsy, this technology is going to be tremendously beneficial and the reason is that doctors can now scan these children as they're moving around and that's never been done before," said Gareth Barnes with Wellcome Trust Neuroimaging Centre.

And it will make it easier to scan people with movement disorders like Parkinson's.