Mastering a New Skill Changes the Architecture of Your Brain

As a former pro athlete turned science reporter, I keep my antennae up for new research that gives us fresh clues about how daily practice and lifestyle habits reshape the human brain. One of my ongoing pet projects is to keep tabs on neuroscience-based studies that shed light on how we can optimize the structure and functional connectivity of our brain's white matter (WM).

For example, a recent postmortem MRI-based brain scan study (Dawe et al., 2021) suggests that regular physical activity across a lifespan may offset cognitive decline by fortifying the brain's white matter microstructure. Other white matter neuroplasticity research (Frizzell et al., 2020) found that two weeks of training practice makes the blood oxygen level dependent (BOLD) signals of WM tracts more robust.

Anecdotally, I've long suspected that fine-tuning the muscle memory required to play sports or to master the sensorimotor skill of touch typing upwards of 100 words per minute without looking at the keys was correlated with intra- and inter-hemispheric white matter changes throughout all four hemispheres of the brain. Much like Braille allows people to read without sight, touch typing relies on a sense of touch, not sight.

Changes in motor, visual, and language-related white matter areas over time

Source: Molendowska aMatuszewski et al., JNeurosci 2021

Learning Braille Changes White Matter Brain Structure Over Time

This week, a white matter plasticity study (Molendowska et al., 2021) was published in the Journal of Neuroscience that shows how learning a new skill can change the functional connectivity and structure of WM over the course of eight months based on the brain's supply-demand needs.

For this longitudinal diffusion tensor imaging study, the researchers investigated white matter microstructural changes among 26 sighted adults who participated in an intensive eight-month training program to learn tactile Braille reading.

First author Malwina Molendowska and colleagues found that when people learn Braille, the architecture of their white matter tracts reorganizes itself based on a blueprint that accommodates new sensorimotor demands.

White matter in somatosensory areas of the cerebral cortex strengthened steadily during the eight-week training course. But WM in the visual cortex didn't start to reorganize until about halfway through the Braille training. According to a July 12 news release, these findings suggest that "white matter reorganizes itself across regions and different timeframes to meet the brain's needs."

Four months of training practice was a turning point when WM microstructure began to change. However, there also appears to be a use-it-or-lose-it aspect to these changes. After two-and-a-half months of not practicing Braille, white matter in somatosensory areas and the visual cortex regions returned to pre-training levels.

Before now, numerous studies had identified the training-induced reorganization of white matter microstructure. But relatively little was known about the temporal dynamics or time frame associated with changes in the brain's WM architecture associated with practicing (and ultimately mastering) a new skill. According to the news release, "Prior studies only examined white matter before and after training, so the exact time course of the changes was not known."

"Taken together, these results demonstrate that white matter plasticity is a highly dynamic process modulated by the introduction of novel experiences," Molendowska et al. conclude. "Our results confirm the supply-demand model of brain plasticity and provide evidence that WM reorganization depends upon distinct computational demands and functional roles of regions involved in the trained skill."

Memory Essential Reads

Why Cramming Doesn't Work

Shaping the "Episodes" of Our Memory

"Practice. Practice. Practice."

In closing, I'm going to filter the latest white matter research on white matter microstructure and the "dynamic nature of learning-induced brain plasticity" through my life experience as an athlete-turned-science-writer and practice-makes-perfect touch typist.

Keyboard finger chart used to master the sensorimotor skill of "touch typing" without looking at the keys.

Source: Albert Stephen Julius/Shutterstock

When I stopped competing in sports at age 38 and decided to write a book, I realized immediately that my touch typing skills were excruciatingly rusty. Instead of being able to type effortlessly without looking at the keyboard, I found myself having to "hunt and peck" for each letter, which depleted my cognitive reserves and prevented me from getting in the zone.

One day, I complained to my mom—who did secretarial work at LIFE magazine in the 1960s and is a speed typist—that my touch typing skills (which I mastered in high school "keyboarding" classes) had deteriorated in the two decades I'd spent doing nothing but sports. She said, "Touch typing is like riding a bike. The muscle memory will come back."

Then, she asked me a simple question, "Are you remembering to feel for the little Braille-like bumps on the "F" and "J" keys with the tips of your index fingers to establish your home-key position?"

In a flash, I realized that I'd overlooked the sensorimotor importance of feeling those little ridges under my index fingers so my brain could remember how to navigate a keyboard without sight.

Within two weeks of starting every writing session by lightly touching the "F" and "J" with the tips of my index fingers and placing my other fingers on their respective home keys, my tactile muscle memory came rushing back; I was touch typing at lightning speed again and experiencing flow states at the keyboard.

Based on the latest white matter research, it seems that the strength of training-induced white matter microstructure changes can atrophy and become less robust without practice. However, based on the supply-demand model of neuroplasticity, if someone reactivates a specific network of white matter tracts that have been pruned due to lack of use, BOLD signals may boost their robustness in about two weeks.

Molendowska and Matuszewski et al. (JNeurosci, 2021) image via EurekAlert