November 22, 2008

Thinking about Not-Thinking

Saw the November 8 copy of NewScientist on the racks at the local public library, and couldn't resist the cover story title, "Vacant Mind, Busy Brain," since I had to think meditation might play a part. In the issue, I found the story, there titled "Private Life of the Brain," and then found it online, where it's titled "The Secret Life of the Brain." [Whew! A many-named thing, this -- but, then, I go by the three names of Tom, Mr. Armstrong, and Hey, You, and God, to some, is God, Jesus and Holy Spirit, so perhaps I shouldn't complain.]

Click to enlargeAnyway, before I touch on the main article, there was indeed a direct Zen connection, told in a green aside-box captioned "the meditating mind," which led me to a PLoS ONE article from September last titled "“Thinking about Not-Thinking”: Neural Correlates of Conceptual Processing during Zen Meditation."

Unhappily, I am not subscribed to PLoS ONE, but I can read the article abstract which includes this esoteric-yet-revealing explanation of the research results: "While behavioral performance did not differ between [Zen practitioners and a control group, the Zen guys] displayed a reduced duration of the neural response linked to conceptual processing in regions of the default network, suggesting that meditative training may foster the ability to control the automatic cascade of semantic associations triggered by a stimulus and, by extension, to voluntarily regulate the flow of spontaneous mentation." How about them apples!! Basically, what this means is that practitioners of meditation have an improved ability to switch which areas of their brains are "turned on." They have more brain control, which, on the physical level, is what happens when people are more in charge of their minds, it seems.

The article begins by citing a study done in 1953 that showed that our brains use just as much oxygen when they are busy, doing arithmetic problems, than when they are seemingly idle, resting with eyes closed. This evidence was at odds with the idea then (and long afterward) that are brains are old-style computers that go into stand-by mode when not brought into use. Indeed, building on the study, scientists now know within the brain is "an organ within an organ" that some now call "the neural dynamo of daydreaming" and others believe has a more-curious role, knitting our memories into a personal narrative. This so-called organ within the brain goes to work when conscious activities become idle -- thus, the brain's constant, level oxygen needs.

A 2001 study identified the regions of the brain that were "turned on" when the consciousness areas were idle. [See article "A default mode of brain function" by Marcus E. Raichle, et al, in the journal Proceedings of the National Academy of Science (aka, PNAS).] This study and subsequent ones [see NewScientist 24Mar2007 p. 36 and Science vol 315, p. 393] say, from what was known about the turned-on regions, that daydreaming is what goes on there.

But now scientists are starting to suspect that the default network does more than just daydream. This from the recent NewScientist article:
Raichle reported last year that the network's resting waves continued in heavily anaesthetised monkeys as though they were awake (Nature, vol 447, p 83). More recently, [Michael D.] Greicius [a prime research scientist in this area of study] reported a similar phenomenon in sedated humans, and other researchers have found the default network active and synchronised in early sleep (Human Brain Mapping, vol 29, p 839 and p 671).

It threw a monkey wrench into the assumption that the default network is all about daydreaming. "I was surprised," admits Greicius "I've had to revamp my understanding of what we're looking at."
Today, Raichle believes "the default network is involved [in] selectively storing and updating memories based on their importance from a personal perspective - whether they're good, threatening, emotionally painful, and so on. To prevent a backlog of unstored memories building up, the network returns to its duties whenever it can."

This research also is an avenue at better understanding dementia. From the article: "[Research scientists] have since found that the default network's pattern of activity is disrupted in patients with Alzheimer's disease. They have also begun to monitor default network activity in people with mild memory problems to see if they can learn to predict who will go on to develop Alzheimer's. [This is of keen interest to me since both my parents had dementia (which was in both cases probably Alzheimer's) when they died. I have some word-find memory problems which, with my parents' histories, suggests I likely will suffer from the disease in the future.]

And now, back to zen meditation: This is merely my speculation, but I think we might suppose that meditation is greatly helpful to us because it begins by organizing our thoughts, behind the scenes. And since this organizing is based on our "personal perspective," a compassionate and wise effort makes us more coherent and harmonious than if the organizing was done without such guidance. Having a more-organized, compassionate, wise and harmonious mind, we are brought closer to the reality of our life and life's meaning, generally. With confusion swept away, enlightenment becomes possible.

3 comments:

~C4Chaos said...

Tom,

thanks for the article and the link to PLoS study. checking it out.

keep it flowing...

~C

Anonymous said...

Hey, PLoS One is an open access journal! It's easy to miss the link to the full text, but it's there...

Tom said...

YES, Anon. Thanks. I didn't see that. I'll correct my article!