१५ जुलै, २०२१

"These past studies of brain plasticity generally focused on gray matter, though, which contains the celebrated little gray cells, or neurons, that permit and create thoughts and memories."

"Less research has looked at white matter, the brain’s wiring. Made up mostly of fat-wrapped nerve fibers known as axons, white matter connects neurons and is essential for brain health. But it can be fragile, thinning and developing small lesions as we age, dilapidations that can be precursors of cognitive decline. Worryingly, it also has been considered relatively static, with little plasticity, or ability to adapt much as our lives change. But Agnieszka Burzynska, a professor of neuroscience and human development at Colorado State University in Fort Collins, suspected that science was underestimating white matter. 'It’s been like the ugly, neglected stepsister' of gray matter, she says, ignored and misjudged.... So, for the new study... they divided the volunteers into groups, one of which began a supervised program of stretching and balance training three times a week, to serve as an active control. Another started walking together three times a week, briskly, for about 40 minutes. And the final group took up dancing, meeting three times a week to learn and practice line dances and group choreography.... In the new scans, the nerve fibers in certain portions of their brains looked larger, and any tissue lesions had shrunk. These desirable alterations were most prevalent among the walkers, who also performed better on memory tests now. The dancers, in general, did not.... Meanwhile, the members of the control group, who had not exercised aerobically, showed declining white matter health after the six months, with greater thinning and tattering of their axons and falling cognitive scores."

From "How Walking Can Build Up the Brain/Older men and women who walked for six months showed improvements in white matter and memory, while those who danced or did stretching exercises did not" (NYT).

Why would dancing and walking produce different results? Burzynska suggests that it might be that these dancers spent time watching instructors rather than moving, so maybe dancing continuously would be as productive of neurogenesis as walking. I couldn't tell if the walking was done outdoors. Maybe the difference is not in the exertion but in the experience of moving through and encountering the real physical world.

And here's something else, as expressed in the most-liked comment over there: "One aspect not addressed by this article: While walking, one is engaged in a kind if relaxed thinking. I walk a lot and constantly think about things - important and mundane things. I make plans, solve problems, talk to myself about issues - walking provides a kind of meditative state while you’re doing it. Not sure why this article never mentions this aspect."

Yes, walking — and, I find, low-key running — does release and sustain a certain kind of flowing, creative thinking — especially if you don't use earbuds to pipe words or music into your head. 

AFTERTHOUGHT: The post title I'm thinking of too late: White Matter Matters.

४ टिप्पण्या:

Ann Althouse म्हणाले...

Tim writes:

"One more benefit of the walking done in this study that is not discussed in the excerpt--they were walking together for 40 minutes, which likely means socializing. Coincidentally, I just read a short discussion (podcast introduction) for "Successful Aging: A Neuroscientist Explores the Power and Potential of Our Lives," which claims, "interacting with others is about the most complex human activity we can do. [snip] You have to listen, focus, remember what’s already been said, read emotions, empathize, give appropriate responses on the fly, and check your inappropriate responses. You have to stay on your mental toes; it’s a delicate and deft dance that maintains your brain’s metaphorical fancy feet."

"If this is a factor, it also explains why the dancers had much less benefit (stayed where they were) and the isolated stretchers had none at all (continued their decline)."

Ann Althouse म्हणाले...

LA_Bob writes:

"From reading your post, it occurred to me it might be purposeful activity, not necessarily the aerobic exercise, that grew the white matter. Of course, it could be both, and of course I'm just thinking out loud here, which I hope helps sustain my white matter.

"Brisk walking strikes me as more purposeful activity than following direction. What would have happened if the "supervised" stretchers and balancers designed and executed (and maybe taught) their own routines? What about any difference between walking alone and walking in a group? Lots of things to explore here.

"There's no mention in the article of myelin or myelination, which is what gives white matter its "whiteness" (and privilege, I suppose). Here's an article about white matter and myelination from about four years ago.

https://www.medicalnewstoday.com/articles/318966#What-is-white-matter?

""Researchers have also demonstrated that using our brains in a specific way can change the structure of white matter. For instance, one experiment found that regularly practicing a musical instrument increases the level of organization within white matter in the areas important for musical performance. The researchers showed that the amount of change was proportional to the number of hours the individual practiced. The more you work, the more white matter is modified."

"So, similar to exercise increasing muscular strength and/or endurance, the more you use the brain, the more white matter you get. I wonder if walkers got a generalized increase in white matter, or if it was specific to certain areas of the brain.

"Nice animation at the link, too.

"Finally, from Wikipedia (https://en.wikipedia.org/wiki/Myelin), "Cholesterol is an essential lipid component of myelin, without which myelin fails to form." I wonder how much damage to white matter can be attributed to statin use. I wonder if aerobic exercise can help offset any such damage."

Ann Althouse म्हणाले...

Birches writes:

"I agree with you. I do my best thinking while I'm running or walking. I do listen to podcasts while I run, but I will sometimes pause and let my thoughts roam around various topics that are stimulated by the podcast subject."

I write:

Yes, I do that with podcasts and audiobooks. It's good to have them to prompt thoughts and to turn them off often, whenever you're producing your own thoughts. Give yourself priority.

Another thing I do is think back over a TV show or movie I watched the previous day or whatever book I've been reading. I am amazed at how many ideas become available to me this way — the depth, the connections.

Ann Althouse म्हणाले...

Chris wrote:

"I used to walk briskly for an hour a day. I was happier and healthier than I’ve ever been. Weight melted, thoughts flowed, and mood lifted when I walked.

"But then I changed jobs and work schedules, and I lost the walking habit. The weight I’d lost returned in time. I realized I shouldn’t have taken the habit and its benefits for granted. Once a habit is gone, I found, it is difficult to reclaim it, especially when the activity itself now prompts a feeling of discouragement.

"But this post has encouraged me to try again to build up a habit of daily walking. Even 15 minutes would make a difference."