In NewScientist (21 Feb 2015) Teal Burrell conveys new information about the brain in “Brain boosting: It’s not just grey matter that matters” (print: “Meet your other Brain”) (paywall):
To test her idea, [Heidi] Johansen-Berg [at the University of Oxford] turned to a 2004 study, which had found that learning a new skill such as juggling changed the density of grey matter – an example of classic synaptic plasticity. Johansen-Berg decided to recreate the study, and measure changes in white matter too. A group of volunteers agreed to learn how to juggle, and after six weeks, brain scans showed that their myelin had increased more than that of a control group who had no training (Nature Neuroscience, vol 12, p 1370).
“We saw a change not only in the grey matter but also in the underlying white matter pathways, suggesting that these pathways strengthen in some way as a result of experience,” says Johansen-Berg. The changes to white and grey matter took place over different timescales, suggesting two separate processes. Johansen-Berg thinks the increase in white matter would have enabled faster conduction along the circuits coordinating juggling. What’s more, the effect was seen in everyone who learned to juggle, regardless of how good they became, which means it is the learning process itself that is responsible.
This was the first study to reveal that training can alter white matter in healthy adults, and it opened the door to a plethora of similar findings. Since then, numerous activities have been linked to extra myelin, from learning to read, to meditating, and learning a new skill like playing the piano or another language.
Myelin is one of the keys to a properly functioning brain, and a lack of it, for any reason, may lead down the path to Alzheimer’s, MS, and ALS.
Harvard contributes information on the apparent role of myelin in accelerating intelligence here, including this possibly contradictory information:
But the new research shows that despite myelin’s essential roles in the brain, “some of the most evolved, most complex neurons of the nervous system have less myelin than older, more ancestral ones,” [Professor Paola] Arlotta, co-director of the HSCI nervous system diseases program, said.
Websites dedicated to reporting on myelin are here and here.
