Researchers the UK found that learning to juggle boosts brain connections by making structural changes in the white matter of the brain. They hope the study will help develop new treatments for diseases such as multiple sclerosis where central nervous system pathways have become degraded.

The study was led by Dr Heidi Johansen-Berg, a Wellcome Trust Career Development Fellow at the University of Oxford and was published online ahead of print on 11 October in the journal Nature Neuroscience.

Johansen-Berg told the media that:

“We tend to think of the brain as being static, or even beginning to degenerate, once we reach adulthood.”

“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,” she added.

Our brains’ white matter contains bundles of long fibres that carry electrical impulses from nerve cell to nerve cell. It is a massive and dense network of lines and junctions. In contrast our brains’ grey matter comprises mostly nerve cell bodies and busies itself with processing and computation.

Although previous studies have shown that learning and practising new skills like juggling that use the visuo-motor part of the brain lead to changes in the grey matter of the adult brain, it was unclear whether it had a similar effect in the white matter.

For this study, which was funded by the Wellcome Trust and Medical Research Council, Johansen-Berg and colleagues used a new form of magnetic resonance imaging (MRI) called “diffusion tensor imaging” to show that the structure of the adult brain’s white matter changes after practising juggling extensively.

Johansen-Berg and colleagues scanned the brains of 48 volunteers who undertook to learn and practise juggling. None of the volunteers could juggle when they started their training which comprised one weekly training session and 30 minutes of daily practice for 6 weeks.

The researchers found changes in regions of the brain’s white matter that are linked with reaching, grasping and peripheral vision.

At the end of the training period, the volunteers reached varying levels of juggling skill, but all those who trained and practised showed changes in white matter, suggesting it wasn’t skill attainment that mattered but the time spent training and practising.

The researchers wrote that they detected:

“A localized increase in fractional anisotropy, a measure of microstructure, in white matter underlying the intraparietal sulcus following training of a complex visuo-motor skill.”

They concluded that:

“This provides, to the best of our knowledge, the first evidence for training-related changes in white-matter structure in the healthy human adult brain.”

Johansen-Berg said they were not suggesting people should now go out and start juggling to improve their brain. She said they just chose juggling as an example of a complex new skill for the volunteers to learn. However, she added that:

“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.”

“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,” said Johansen-Berg.

“Training induces changes in white-matter architecture.”
Jan Scholz, Miriam C Klein, Timothy E J Behrens & Heidi Johansen-Berg.
Nature Neuroscience, Published online ahead of print 11 October 2009.

Additional source: Wellcome Trust.

Written by: Catharine Paddock, PhD