It’s no longer just a party trick. Juggling and probably other visual skills that take time to master increase the size of your brain.
That’s the conclusion of German researchers, which throws down the gauntlet to the mainstream view that the size of the adult brain does not change at all except when confronted by aging or disease.
University of Regensburg neurologist Arne May and colleagues asked 12 people in their early 20s, most of them women, to learn a classic three-ball juggling trick over three months until they could sustain a performance for at least a minute. Another 12 were a ‘control’ group who did not juggle.
All the volunteers were given a brain scan with magnetic resonance imaging (MRI) at the program’s start and a second after three months.
After this, the juggling group was told not to practice their skills for three months, and then a third scan was taken of all 24 volunteers.
The scans found that learning to juggle increased the volume of gray matter in the mid-temporal area and left posterior intra-parietal sulcus by about three percent. These are parts of the brain’s left hemisphere that process data from visual motion.
Students who had not undergone juggling training showed no such change.
After the third scan, when many recruits had forgotten how to juggle, the increases in gray matter had partly subsided.
That proves that the anatomical change had been only temporary in the researchers’ view.
Our results contradict the traditionally held view that the anatomical structure of the adult human brain does not alter, except for changes in morphology caused by aging or pathological conditions,’ their study says.
Quite why the brain’s size should grow and contract in response to the demand for learning is unclear.
The change could be caused by an increase in the production of neurons (brain cells) to cope with the data-processing burden or, alternatively, by changes in the connections between the cells, the authors speculate.
Their study was published in Nature, the British weekly science journal.
