The Forgetting: Understanding Alzheimer’s: A Biography of a Disease. David Shenk

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СКАЧАТЬ so otherwise sophisticated but with an apparent built-in fuzziness, a tendency to regularly forget, repress, and distort information and experience?

      The answer, it turns out, is that fuzziness is not a severe limitation but a highly advanced feature. As a matter of engineering, the brain does not have any physical limitations in the amount of information it can hold. It is designed specifically to forget most of the details it comes across, so that it may allow us to form general impressions, and from there useful judgments. Forgetting is not a failure at all, but an active metabolic process, a flushing out of data in the pursuit of knowledge and meaning.

      We know this not just from brain chemistry and inference, but also because psychologists have stumbled upon a few individuals over the years who actually could not forget enough—and were debilitated by it.

      In his New Yorker profile, Mark Singer wonders if Martin Scorsese is such a person—burdened by too good a memory.

      Was it, I wondered, painful to remember so much? Scorsese’s powers of recall weren’t limited to summoning plot turns or notable scenes or acting performances; his gray matter bulged with camera angles, lighting strategies, scores, sound effects, ambient noises, editing rhythms, production credits, data about lenses and film stocks and exposure speeds and aspect ratios.… What about all the sludge? An inability to forget the forgettable—wasn’t that a burden, or was it just part of the price one paid to make great art?

      For some perspective on the inability to forget, consider the case study that psychologists call S. In the 1920s, S. was a twenty-something newspaper reporter in Moscow who one day got into trouble with his editor for not taking notes at a staff meeting. In the midst of the reprimand, S. shocked his boss by matter-of-factly repeating everything that had been said in the meeting—word for word.

      This was apparently no stretch at all for S., who, it emerged upon closer examination, remembered virtually every detail of sight and sound that he had come into contact with in his entire life. What’s more, he took this perfect memory entirely for granted. To him, it seemed perfectly normal that he forgot nothing.

      The editor, amazed, sent S. to the distinguished Russian psychologist A. R. Luria for testing. Luria did test him that day, and for many other days over a period of many decades. In all the testing, he could not find any real limit to his capacity to recall details. For example, not only could he perfectly recall tables like this one full of random data after looking at them for just a few minutes:

      And not only could he efficiently recite these tables backwards, upside down, diagonally, etc., but after years of memorizing thousands of such tables he could easily reproduce any particular one of them, without warning, whether it was an hour after he had first seen it, or twenty years. The man, it seemed, quite literally remembered everything.

      And yet he understood almost nothing. S. was plagued by an inability to make meaning out of what he saw. Unless one pointed the obvious pattern out to him, for example, the following table appeared just as bereft of order and meaning as any other:

      “If I had been given the letters of the alphabet arranged in a similar order,” he remarked after being questioned about the 1–2–3–4 table, “I wouldn’t have noticed their arrangement.” He was also unable to make sense out of poetry or prose, to understand much about the law, or even to remember people’s faces. “They’re so changeable,” he complained to Luria. “A person’s expression depends on his mood and on the circumstances under which you happen to meet him. People’s faces are constantly changing; it’s the different shades of expression that confuse me and make it so hard to remember faces.”

      Luria also noted that S. came across as generally disorganized, dull-witted, and without much of a sense of purpose or direction in life. This astounding man, then, was not so much gifted with the ability to remember everything as he was cursed with the inability to forget detail and form more general impressions. He recorded only information, and was bereft of the essential ability to draw meaning out of events. “Many of us are anxious to find ways to improve our memories,” wrote Luria in a lengthy report on his unusual subject. “In S.’s case, however, precisely the reverse was true. The big question for him, and the most troublesome, was how he could learn to forget.”

      What makes details hazy also enables us to prioritize information, recognize and retain patterns. The brain eliminates trees in order to make sense of, and remember, the forests. Forgetting is a hidden virtue. Forgetting is what makes us so smart.

      

      One of the worst things that I have to do is put on my pants in the morning. This morning I kept thinking there is something wrong because my pants just didn’t feel right. I had put them on wrong. I sometimes will have to put them on and take them off half a dozen times or more.… Setting the washing machine is getting to be a problem, too. Sometimes I’ll spend an hour trying to figure out how to set it.

      —B.

      San Diego, California

       Chapter 4 THE RACE

      Taos

      “Ten years to a cure,” a Japanese scientist whispered to me in our hotel lobby as we waited for the shuttle bus to the Taos Civic Plaza.

      The whisper was as telling as the words. He couldn’t contain his optimism, and yet he also couldn’t afford to put it on display.

      Other Alzheimer’s researchers had lately been adopting a similar posture. As scientists, they were reserved by nature. But the recent acceleration of discovery had made them a little giddy. Hundreds of important discoveries had come in recent years, and funding for research was way up. The study of Alzheimer’s was now in the top scientific tier, alongside heart disease, cancer, and stroke research. This seemed fitting, since the disease was emerging as one of the largest causes of death in the U.S., not far behind those other three.

      There was now even an Alzheimer’s drug on the market. Aricept, introduced in 1997, which boosted the brain’s supply of the neurotransmitter acetylcholine. Some of the functional loss in early Alzheimer’s involves a deficiency of acetylcholine; replenishing it with this drug seemed to help about half of early and middle-stage patients to slow or even arrest the progression of symptoms for a year or more.

      On the one hand, this was a giant advance: a real treatment that often made a tangible difference. But it was also a frustrating baby-step: Aricept did not slow the advance of the actual disease by a single day. It only worked on the symptoms. Scientists couldn’t stop Alzheimer’s yet—only put a thick curtain in front of it for a while.

      More ambitious advances were brewing. An electronic update service named Alzheimer’s Weekly had been launched in 1998. Neurologists in the 1960s would have considered this phrase a sarcastic reference to the drudging nature of discovery: Understanding of the disease was practically frozen for more than half a century. But after a thaw in the 1970s and a renewed effort in the ’80s, genetic and molecular discoveries started to cascade so quickly by the mid-1990s that the excavation of Alzheimer’s seemed to be moving at the same clip as sporting events and financial markets.

      Now a weekly update was not only useful but essential. In fact, updates on other Web sites came almost daily:

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