Human see, human do

Ballet dancers’ brains reveal the art of imitation

Scientists have discovered that a system in our brain which responds to actions we are watching, such as a dancer’s delicate pirouette or a masterful martial arts move, reacts differently if we are also skilled at doing the move. The University College London (UCL) study, published in the latest online edition of Cerebral Cortex, may help in the rehabilitation of people whose motor skills are damaged by stroke, and suggests that athletes and dancers could continue to mentally train while they are physically injured.

In the UCL study, dancers from the Royal Ballet and experts in capoeira – a Brazilian martial arts form – were asked to watch videos of ballet and capoeira movements being performed while their brain activity was measured in a MRI scanner. The same videos were shown to normal volunteers while their brains were scanned.

The UCL team found greater activity in areas of the brain collectively known as the ’mirror system’ when the experts viewed movements that they had been trained to perform compared to movements they had not. The same areas in non-expert volunteers brains didn’t care what dance style they saw.

While previous studies have found that the system contains mirror neurons or brain cells which fire up both when we perform an action and when we observe it, the new study shows that this system is fine tuned to each person’s ’motor repertoire’ or range of physical skills. The mirror system was first discovered in animals and has now been identified in humans. It is thought to play a key role in helping us to understand other people’s actions, and may also help in learning how to imitate them.

Professor Patrick Haggard of UCL’s Institute of Cognitive Neuroscience says: “We’ve shown that the mirror system is finely tuned to an individual’s skills. A professional ballet dancer’s brain will understand a ballet move in a way that a capoiera expert’s brain will not. Our findings suggest that once the brain has learned a skill, it may simulate the skill without even moving, through simple observation. An injured dancer might be able to maintain their skill despite being temporarily unable to move, simply by watching others dance. This concept could be used both during sports training and in maintaining and restoring movement ability in people who are injured.”

Dr Daniel Glaser of UCL’s Institute of Cognitive Neuroscience says: “Our study is as much a case of ’monkey do, monkey see’ as the other way round. People’s brains appear to respond differently when they are watching a movement, such as a sport, if they can do the moves themselves.

“When we watch a sport, our brain performs an internal simulation of the actions, as if it were sending the same movement instructions to our own body. But for those sports commentators who are ex-athletes, the mirror system is likely to be even more active because their brains may re-enact the moves they once made. This might explain why they get so excited while watching the game!”

Deborah Bull, Creative Director at Royal Opera House (ROH2), says: “We are delighted to be working with Patrick Haggard, our Associate Scientist, on this fascinating area of research. As a former dancer, I have long been intrigued by the different ways in which people respond to dance. Through this and future research, I hope we’ll begin to understand more about the unique ways in which the human body can communicate without words.”