The visual areas of the brain showed activity. But the real differences were found in two areas related to movement - the pre-motor cortex and the visual-motor integration cortex.
Both these ‘movement’ areas of the brain showed more activity when a skilled dancer saw movements he had been trained to perform, compared with watching movements he hadn't been trained to perform. It was as if the movement part of his brain was resonating with the moves he knew.
Click here to hear Daniel Glaser talk about these results
Other people (ie those who weren’t dancers) were also scanned. There was no difference in their brain activity whether they watched ballet or capoeira – their brains did not discriminate.
This shows that the dancers combine what they saw with their own personal ‘motor repertoire’ – and this shows up differently in their brain scans.
It also shows that by lying still and simply watching other people move, you can activate movement areas of the brain as if you were moving yourself!
Your astounding ‘mirror neurons’
Scientists have known for many years that when a monkey reaches out and grabs a peanut, motor command neurons fire in his brain. A different, nearby neuron will fire when that monkey for example pulls something towards him.
Giacomo Rizzolatti working in Italy has discovered these same neurons fire when a monkey simply WATCHES another monkey grabbing a peanut, or WATCHES another monkey pulling something towards him.
This is a truly fantastic discovery because the visual image of someone else grabbing a peanut is entirely different from the image of yourself doing it. It implies a different type of representation.
Early results suggest that humans have more extensive mirror systems than monkeys.
Why do we have mirror neurons?
Mirror neurons are likely to be vitally important to human behaviour – to interpret other people’s actions and intentions. They have probably been fundamental to our evolution, allowing us to imitate our parents and quickly transfer skills and culture to the next generation.
Why is this experiment important?
These findings might one day help people who have lost movement due to a stroke. Once the brain has learned a skill, it’s possible to stimulate this brain area by watching someone else do the activity.
Perhaps greater knowledge of the mirror system could help injured athletes and dancers. They could continue to train without moving a muscle – by simply watching someone else do the movements until their bodily injury had recovered.
There is also an appealing though completely untested idea that maybe disorders such as autism are in some way related to disruption of these mirror neuron systems.