人类其实是人老大脑不老

当你老了的时候，你的大脑会不如从前吗？或许很多人都会这么认为吧，毕竟老年人记忆力下降，对于新知识的吸收较年轻人而言似乎都略逊一筹。但其实，你的大脑和以前一样，甚至比原先做的更出色。

RENEE MONTAGNE, host:

If you walk up to people old enough to have college-age kids - that would be middle-aged adults - and you asked them how is your brain functioning these days, you're likely to hear answers like this...

Ms. RUTH ALICE WHITE: Well, I ran into somebody that I had worked with for several years and could not remember her name at all, and it was really embarrassing.

Mr. PAT HARDY: And I'm dismayed by the number of times that I walk into a room and then I look around and say, Wait a minute, what's in here that I could have come for?

Ms. JENNIFER TURVOID: I forgot something really big last weekend and I can't remember what it is. It was like someplace I needed to be or like I took the kids to the wrong place. It was pretty funny in hindsight. Like I can't believe I forgot that, but I did.

MONTAGNE: You could call them small stumbles, but the fact is people are not imagining them. Scientists tell us that as we careen through middle age, our brains do slow down. People have trouble retrieving names, get easily distracted. But the news is nowhere as bad as one might think.

In fact, science writer Barbara Strauch set out to explain why brainsfalter in middle age and wound up writing a book about how brains can flourish. The book is called "The Secret Life of the Grown-up Brain," and by grown-up she means people roughly between the ages of 40 and 65.

Ms. BARBARA STRAUCH (Author, "The Secret Life of the Grown-up Brain"): They used to think that it was one big slide, a decline, and that we lost 30 percent of our brain cells as we aged. Now they know, as they look in there with brain scanners and things year after year, we don't. In fact, we keep our brain cells pretty intact, as long...

MONTAGNE: Which is a relief.

Ms. STRAUCH: It's a huge finding, actually, and has completely flipped around how we think about how the brain ages. There is some shrinkage here and there, but in general our brains, if there isn't a disease of some sort, basically we can do quite fine.

MONTAGNE: You have research that suggests that middle age people shouldn't panic about their brains, because actually they're getting better. Start us with one.

Ms. STRAUCH: Well, for instance, there're some studies that started in the 50s that traced the same people throughout their lives, and they find that in this middle span we are higher - have the higher scores on cognitive tests in a whole range of areas, including things like inductive reasoning, believe it or not verbal memory, vocabulary - we're better in that span of time than we were when we were in our 20s.

MONTAGNE: Well, one of the studies, to give an example of how this might work, was one of air traffic controllers who were in their mid-60s.

Ms. STRAUCH: Right. They went to Canada to study controllers who can work till they're 65. And they found some cognitive declines on tests. But when you actually test them in what they're supposed to be doing, for instance, keeping planes from colliding with each other, they do just as well as they did when they were younger, as do pilots.

MONTAGNE: Well, is Chesley Sullenberger, who's quite famous now, the pilot who ditched the U.S. Airways plane in the Hudson so perfectly, is he an example of that?

Ms. STRAUCH: He is, in fact. And it's not only him. The whole crew is what they call senior. It was an amazing story, actually. We had ferry boat captains and tugboat captains all watching this happen. Many of them middle-aged; and they all, in a split second, made all the right decisions; and so we had a kind of a middle-aged extravaganza that came out quite well.

MONTAGNE: We all talk about gray matter. Youve been talking about that, how the brain, in fact, a lot of that gray matter doesnt die. But there's also, as you describe in the book, white matter.

Ms. STRAUCH: Mm-hmm.

MONTAGNE: Tell us about that. And it turns out to be quite a good thing.

Ms. STRAUCH: Right. It's fat, actually. It's fatty stuff that kind of coats the long tails of the brain cells. And so, as we do things, as we learn things, the white matter increases and the brain signals move faster. And this was also a shock but they find that the white matter peaks in middle age. So that itself might be middle-aged wisdom. Because the brain sees connections, it sees the full picture. As one friend of mine, she's an AIDS doctor in her 50s, she says, when I walk into a hospital room now, you know, I can size up the situation much faster. We get to the gist of an argument faster. Some people think we can be even more creative because we see these connections.

MONTAGNE: In the book, you also talk about middle age people can protect their brains from the natural effects of aging.

Ms. STRAUCH: Mm-hmm.

MONTAGNE: And one of the more compelling strategies seems to be exercise.

Ms. STRAUCH: You know, the science at this point, the best science is on exercise. The brain, is much more like the heart than we thought, so - and they find things like walking around a track three times a week increases brain volume. They find that exercise increases the ability of the brain to produce new baby brain cells, which nobody thought was possible, anyhow, as an adult, until a few years ago. It does have to be exercise that gets your heart going but it doesnt have to be marathon.

MONTAGNE: What did you learn that tells us where to from here? As one moves into the 70s and beyond, will the brain hang in there, unless there's disease?

Ms. STRAUCH: Well, there's all sorts of things that can happen. Cardiovascular disease, of course, of any sort affects the brain, strokes and things like that. But what they find, also, in middle age is this when the brain they think is on the cusp. There's a great deal of variability as we go through middle age and some brains just keep going on fine and some brains don't. And so what they're trying to figure out is: what's the difference? And that really makes middle age, what we do during the spam of time, even more important.

MONTAGNE: Youre taking care of yourself is sort of what you say.

Ms. STRAUCH: Mm-hmm.

MONTAGNE: But crossword puzzles and mind games and experiences where you're challenging yourself, is that partly what you're talking about?

Ms. STRAUCH: Yes. I mean I think that crossword puzzles are kind of thought to be not enough anymore. You're kind of retrieving stuff you already know, there's nothing wrong with them. But what they do know is that, one way or another, you have to push your brain very hard. You have to make it not comfortable. And there's some science that says that things like, even talking to people who disagree with you, is good. Basically, it helps you sharpen your own thinking; it challenges those the brain likes a good rut, and we need to kick them out of those ruts a little bit. You know, if you always watch MSNBC, maybe you should switch to Fox or vise versa, just to get your blood boiling a little bit.

MONTAGNE: That's New York Times science editor Barbara Strauch, who told us that actually, blood is less likely to boil as we get older.

Go to NPR.org to hear why older adults accentuate the positive. You can also read excerpts from her book, "The Secret Life of The Grown-up Brain."

(Soundbite of song, "My Brain")

Mr. MOSE ALLISON (Musician, songwriter): (Singing) My brain is always ticking, my brain. My brain is always ticking, my brain. My brain is always ticking...

MONTAGNE: You're listening to MORNING EDITION from NPR News.