Neuroscientists have discovered that learning to juggle causes changes in white matter, the nerve strands which help different parts of the brain communicate with each other.
University of Oxford researchers recruited 48 healthy young adults who were unable to juggle and put them in a functional magnetic resonance imaging (fMRI) scanner to get a cross-section map of their brain.
Half the volunteers then underwent a six-week training period to learn how to juggle, during which they were also encouraged to practise for 30 minutes a day.
At the end, they were all able to perform at least two cycles of the classic three-ball "cascade."
They were then scanned again, as were their 24 non-juggling counterparts.
Among the juggling group, imaging showed important changes in white matter, the bundle of long nerve fibres that carry electrical signals between nerve cells and connect different areas of the brain.
So-called grey matter consists of areas of nerve cells where the brain processes information.
The findings, published online on Sunday by Nature Neuroscience, are important, for they suggest the brain remains "plastic" -- or mobile and adaptable -- beyond childhood.
"We tend to think of the brain as being static, or even beginning to degenerate, once we reach adulthood," the study's leader, Heidi Johansen-Berg, said in a press release.
"In fact we find the structure of the brain is ripe for change. We've shown that it is possible for the brain to condition its own wiring system to operate more efficiently."
Juggling was selected for the experiment because it is a difficult motor skill to master, which means that any cerebral changes would show up more readily.
To juggle requires accurate arm and hand movements, grasping of fast-moving objects and the ability to track objects in the periphery of one's vision.
In fact changes in white matter seen after six weeks occurred precisely in those parts of the brain that are involved in these tasks.
"This doesn't mean everyone should go out and start juggling to improve their brains," said Johansen-Berg.
"We chose juggling purely as a complex new skill for people to learn. But there is a 'use it or lose it' school of thought, in which any way of keeping the brain working is a good thing, such as going for a walk or doing a crossword."
Johansen-Berg said clinical applications could eventually follow, such as ways to stimulate the brain and maintain neurological health.
"Knowing that pathways in the brain can be enhanced may be significant in the long run in coming up with new treatments for neurological diseases, such as multiple sclerosis, where these pathways become degraded."Reuse content