Sunday, January 21, 2007

Time does science (hopefully not for the last time)

When I received the latest issue of Time a few days ago, I was excited to see that the cover story was "The Brain: A User's Guide." (I also got a little sad, because I recently heard from someone who works there that the magazine's ongoing restructuring may mean that there are fewer science cover stories, despite the fact that they sell amazingly well.)

I haven't read all of the articles yet, but here were the highlights from what I've read so far.

There is an article about brain rewiring that is actually an excerpt from Sharon Begley's new book The Mind and the Brain. Among other things, it reports on research that challenges the long-held hypothesis that a person's "happiness set point" is (as implied by the phrase) basically unmovable. A person's happiness, it was thought, returns to approximately the same level even after great tragedy or joy. But recently, Richard Davidson from the University of Wisconsin-Madison (with the help of the Dalai Lama) recruited Buddhist Monkswho had spent more than 10,000 hours of their lives meditatingfor tests in which they were asked to meditate under fMRI scans. The scans showed "dramatic changes in the parts of the brain associated with happiness" as compared to a group of students who had recently undergone a crash course in meditation. Begley writes,

But perhaps the most striking difference was in an area in the left prefrontal cortexthe site of activity that marks happiness. While the monks were generating feelings of compassion, activity in the left prefrontal swamped activity in the right prefrontal (associated with negative moods) to a degree never before seen from purely mental activity. By contrast, the undergraduate controls showed no such differences between the left and right prefrontal cortex. This suggests, says Davidson, that the positive state is a skill that can be trained.

For the monks as well as the patients with depression or OCD, the conscious act of thinking about their thoughts in a particular way rearranged the brain. The discovery of neuroplasticity, in particular the power of the mind to change the brain, is still too new for scientists, let alone the rest of us, to grasp its full meaning. But even as it offers new therapies for illnesses of the mind, it promises something more fundamental: a new understanding of what it means to be human.

This I find fascinating. I have never doubted that meditation had positive health effects, but this research implies that meditationor, more broadly, the practice of particular thought patternscan rewire the brain.

Begley's article also mentions another interesting finding. Not only does the repeated use of certain musclessay, by practicing a certain passage on the piano each daycause the brain to "devote more cortical real estate to it," even just imagining the practicing elicits the effect:

"Mental practice resulted in a similar reorganization" of the brain, Pascual-Leone later wrote. If his results hold for other forms of movement (and there is no reason to think they don't), then mentally practicing a golf swing or a forward pass or a swimming turn could lead to mastery with less physical practice. Even more profound, the discovery showed that mental training had the power to change the physical structure of the brain.
Steven Pinker has an interesting article about the nature of consciousness, in which he describes the so-called "Easy Problem," the difference between conscious and unsconscious thoughts, and the "Hard Problem," or why there is first-person, subjective experienceand why it's so difficult to solve this problem. (I recall being in elementary school and asking my parents how I could be sure that the "green" I saw was the same color that my classmates saw when they saw green. This article gets at just that.) There's also an interesting (and mildly amusing) sidebar by Daniel Dennett that begins, "Suppose Steve Pinker contracts a terrible progressive brain disease..."

article by Michael Brunton argues that we may have been giving babies too much credit. Challenging research from the '80s that suggested babies have a certain amount of "built-in knowledge" about the workings of the world, new research suggests that "a baby's fascination with physically impossible events merely reflects a response to stimuli that are novel."

And our memories are heavily driven by emotion, writes senior staff writer Michael Lemonick in his piece, "The Flavor of Memories." He points out something I never knew: the reason that memories grow more inaccurate over time has to do with the fact that when we remember old events, we are not calling up the original memory but the last time we thought about it:
Each time we retrieve and re-store a memory, it can be subtly altered by all sorts of factors. What goes back into our brains is like the new version of a text document, overwriting the old.
And last but certainly not least, there was a very interesting essay by Harvard psychologists Daniel Gilbert and Randy Buckner. When people are not performing specific mental tasks that require them to be "in the moment"like following instructions, or answering the telephonewhat are their brains doing? Traveling through time, apparently, either re-living past events or imagining the future. Gilbert and Buckner offer some potential reasons for this:
Why did evolution design our brains to go wandering in time? Perhaps it's because an experience is a terrible thing to waste. Moving around in the world exposes organisms to danger, so as a rule they should have as few experiences as possible and learn as much from each as they can. Although some of life's lessons are learned in the moment ("Don't touch a hot stove"), others become apparent only after the fact ("Now I see why she was upset. I should have said something about her new dress"). Time travel allows us to pay for an experience once and then have it again and again at no additional charge, learning new lessons with each repetition. When we are busy having experiencesherding children, signing checks, battling traffic--the dark network is silent, but as soon as those experiences are over, the network is awakened, and we begin moving across the landscape of our history to see what we can learnfor free.
Certainly some fascinating pieces herethere are more I haven't read yet, tooand most appear to be available for free online, at least for now.


Blogger Karen said...

Keep it up, and I won't have to fork over the newsstand price for this baby! :P

That stuff about memories is completely new to me. I suppose it partially explains why when I tell a little white lie over and over again, I sometimes get to the point where I actually believe it's true. My fabricated stories are overwriting my truthful memories!

1:50 PM  

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