A new study just published in PLoS One reports that learning to juggle alters the structure of motion detection areas in the brain within as little as 7 days.
Led by neuroscientist Joenna Driemeyer, the study builds on a previous research that also found juggling could alter brain structure, although this previous study waited three months before the brain was checked for alterations using high resolution structural MRI scans.
This new study also took 20 non-jugglers and asked them to learn to juggle, but scanned them after 7, 14 and 35 days.
After only 7 days, a motion specialised part of the occipital lobe known as V5 had increased in density. In both studies, the changes were maintained over the subsequent weeks of practice, but these areas returned to their pre-learning state after several weeks without juggling.
This is an interesting example of rapid ‘neuroplasticity‘, the ability of the brain to adapt structurally to new situations.
However, the authors are careful to note that they can’t tell whether the brains of the participants had generated more neurons, or whether existing cells grew in size, or additional glial cells were developed, or maybe there were just changes in how much blood or other brain fluids packed the area.
Also, the fact that changes seemed to occur at the beginning of the learning cycle but that further practice maintained but didn’t cause additional changes led the researchers to speculate that learning a variety of new things, rather than simply practising old skills, may be most effective in terms of brain structure alterations.
Link to ‘Changes in Gray Matter Induced by Learning ‚Äî Revisited’.
Link to PubMed entry for paper.
Full disclosure: I’m an unpaid member of the PLoS One editorial board.
Mind Hacks 
I saw this in PLoS, too.
What I find fascinating is that all of the research evidence of brain plasticity reminds one so much of the effects of stimuli on the body’s musculature: The right physical exercise strengthens and modifies our musculature. The right mental exercise does the same for the brain.
Hello,
If you’re interested in neuroplasticity, there is an excellent dialogue between Richard Davidson and Daniel Goleman entitled “Training the Brain: Cultivating Emotional Skills.” It is available at http://www.morethansound.net.
i am a chartered psychologist and therapeutic counsellor. I have for the last year been adapting my clinical practice in an addiction agency to Utilize neuroplasticity, the results so far have been very positive in the area of changing clients habits and perceptions. in some cases the client has not only stopped drinking but finds the thought of drinkin alcohol nauseous.
I wonder if one might see change in brain structure from multiple long term periods of juggling, where on the later periods, it had been months since the subject had lay juggled. As a long time juggler who has had periods without practice, I do feel that my focus is generally improved during periods of consistent effort towards growth.