The study, published in 'Neuron', has revealed that introducing completely new facts when learning, significantly improves memory performance.

Researchers have long suspected that the human brain is particularly attracted to new information and that this might be important for learning. They are now a step closer to understanding why.

Dr Emrah Düzel, UCL Institute of Cognitive Neuroscience, said: "We hope that these findings will have an impact on behavioural treatments for patients with poor memory. Current practice by behavioural psychologists aims to improve memory through repeatedly exposing a person to information – just as we do when we revise for an exam.

"This study shows that revising is more effective if you mix new facts in with the old. You actually learn better, even though your brain is also tied up with new information.

"It is a well-known fact amongst scientists that the midbrain region regulates our levels of motivation and our ability to predict rewards by releasing dopamine in the frontal and temporal regions of the brain. We have now shown that novelty activates this brain area.

"We believe that experiencing novelty might, in itself, have an impact on our dopamine levels. Our next project will be to test the role of dopamine in learning. These findings could have implications for drug development."

Separate behavioural experiments were also conducted without the use of a scanner to test the subjects' memory. Their memory of the novel, familiar and very familiar images they had studied was tested after 20 minutes and then a day later.

Subjects performed best in these tests when new information was combined with familiar information during learning. After a 20 minute delay, subjects' memory for slightly familiar information was boosted by 19 per cent if it had been mixed with new facts during learning sessions.