Tuesday, May 25, 2010

Why Do We Forget Things?

By Martha Weinman Lear

Before I forget, let me ask: Is your dinner-table talk as snappy as ours?

“Remember I asked you to remind me to call someone?” “Yes.” “Who was it?” “I forget.”

And: “What did I go to the kitchen for?” “How do I know?” “You asked me to get it.” “Get what?”

And: “I saw Whatsisname today.” “Who?” “You know. Whatsisname.” “Oh. Where?”

If this sounds familiar, and if you ever complain about your memory, join the crowd. There are millions of us out here, complaining more about remembering less. Memory specialists, of whom I have interviewed a slew, say that forgetfulness is the top health concern of baby boomers. And they’re not the only ones. “My memory is awful,” says my dental hygienist, Eve, 36, as she tenderly macerates my gums. “Does that mean I’m likelier to get demented?” I shake my head no. “Good,” she says, “because I sure worry.”

The Worried Well, therapists call them. They worry because they do not know that this type of memory loss is normal. Normal, friend. Universal. So universal that the phrase “it’s on the tip of my tongue” is used in more than 40 languages.

With normal aging, what we lose is not memory in general but a particular kind. We have many kinds. One is procedural memory, which is how-to-walk, how-to-eat, how-to-tie-a-shoe memory. It’s what Sinatra never thought about when he sang, Astaire never thought about when he danced, Tiger Woods doesn’t think about when he swings a golf club. (If he did, it might ruin his stroke.) It is memory we use unconsciously, and it is the strongest kind we have.

A second is semantic memory, which covers facts. What is a key? What are eyeglasses? What is a movie?

And a third is episodic memory, which covers experience. I’ve lost my keys. Where did I leave my glasses? Who was in that movie? This is the type that starts playing tag with us in the sweet fullness of time. Here’s why.

That 3-pound miracle tucked into your skull has 100 billion neurons zapping around wildly, sending each other the electrical and chemical signals that make memories. With time, the signals weaken. Brains shrink by about half a percent a year, starting around age 30—though usually we don’t notice any change for years. And here’s the rub. Episodic memory relies heavily on the front areas of the brain, the frontal lobes—the very areas that start shrinking first.

The loss isn’t that big, really. It feels big, because we perceive a huge difference between a brain buzzing along at full strength and one operating at, say, 95%. But it’s just a slowing down. That elusive name is probably not gone—it simply takes longer to pop up. Which raises a question everyone always asks: Is everything that ever went into my brain still there? Answer: Nobody knows. (How would you find out?)

Many researchers do believe it’s all there but in altered form. “The disc is full,” we say, and, “No room on my hard drive”—but the computer analogy is not really accurate. As Dr. Barry Gordon, a neurologist at Johns Hopkins points out, computer memory is exact; brain memory is fluid. Whenever you make or retrieve a memory, its pattern of signals is altered. Sort of like writing over writing. Which is why, as time passes, our memories are apt to change and deceive us.

We accept other changes in our bodies. We consider it natural that we won’t play tennis at 50 as we did at 20, but we cannot accept that our brains also may slow down. It’s simply too threatening.

Scientists who understand the why of memory are not so easily threatened. I ask Dr. Richard E. Powers, chairman of the medical advisory board of the Alzheimer’s Foundation, if he has memory problems. “A group of doctors my age were laughing about the changes we observe,” he says. “At 25, we could read a scientific article once and absorb it. Now we have to read it several times. At 57, my ability to hold onto new information is not as good as it used to be—but we retain the capacity to store and use the information. It’s like flypaper that’s been lying a long time on the counter: It’s still got plenty of stick but not as much as it used to have.”

We actually may be wired to forget. Consider: If everything stuck to that mental flypaper, we would be in big trouble. We’d be overwhelmed by trivia. The longer we live, the more memories we stuff into our brains, and the harder it may become to locate any particular one. So those that we need least, the episodic memories, get stored in the attic first. After all, how important is it (how does it help you survive in the world) to remember the name of that restaurant you ate at last night? What is important to remember is what “eating” means and how to eat.

Think of our kind of memory loss as nature’s priority filing system—often irritating but practical and desirable in the great Darwinian scheme of survival. And normal—a lovable word. It comes with the territory of healthy longevity. And when you consider the alternatives, as they say, it’s the best deal in town.

Make Your Memory Better

1 ASSOCIATE NAMES. Link what you want to remember to what you already know. You meet a Jennifer: Picture her in your mind’s eye with other Jennifers—Aniston (above), Lopez. Visualize them together, which is what makes it work.

2 GET ORGANIZED. Dr. Margaret Sewell, director of the Memory Enhancement Program at Mount Sinai Hospital in New York, suggests changing the way you organize your tasks. For example, no calls and no e-mail until the current job is done. “It’s amazing,” she says, “the difference people see as they cut down on nonessential multi-tasking.”

3 CONCENTRATE MORE. Tests show that in absorbing new facts, we are no less competent than 20-year-olds, just slower. “Concentrate a little harder and practice more,” says Dr. Sewell. “You want to learn Italian when you’re 90? OK! It will take you a little longer but, assuming there’s no pathology, you can do it!”

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