首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
The Magic of Memory —By Laurence Cherry Our memories are
The Magic of Memory —By Laurence Cherry Our memories are
admin
2010-07-14
12
问题
The Magic of Memory
—By Laurence Cherry
Our memories are probably our most cherished possessions. More than anything else we own, they belong uniquely to us, defining our personalities and our views of the world. Each of us can summon thousands of memories at will: our first day at school, a favorite family pet, a summerhouse we loved. And yet the marvel of memory continues to be a tantalizing (挑逗性的) mystery. Nevertheless, within the past few years great advances have been made in understanding what memory is, how it works, and how it may possibly be improved. "We’re standing at the brink of a whole new era in memory re search," says Dr. Steven Ferris, a psychologist at the Millhauser Geriatric (老年医学的) Clinic. "For the first time, there’s a general feeling that we’re really on the right track."
For years, the prevailing theory was that remembering was somehow connected to electrical activity inside the brain. But within the past decade, it’s become clear that chemical changes must also be involved, otherwise our memories could never survive deep-freeze, coma, anesthesia (麻醉) and other events that radically disrupt the brain’s electrical activity. Ingenious re search over the past few years has demonstrated that biochemical changes do indeed accompany learning and remembering. In one dramatic experiment, mice, who usually prefer the safety of darkness, were taught to fear the dark and were then killed. Extracts of their brains were injected into untrained mice, and they then began to shun the dark. Other experimenters have shown that the amounts of certain chemicals, such as RNA (核糖核酸), radically in crease with learning, as do the amounts of certain neurotransmitters (神经传递素 )—chemicals released by brain cells that help conduct nerve impulses from one brain cell to another. Memory, then, is also chemical in nature, al though exactly in what way remains a mystery.
Almost all memory researchers now agree that our brains record—and on some level remember—everything that ever happens to us. Many people who’ve narrowly escaped sudden death, such as soldiers and mountain climbers, have reported that in the few seconds that seemed left to them a stream of long-lost memories flashed before them. The first experimental confirmation that the brain does record every experience in this minute way came some years ago from Dr. Wilder Penfield of the Montreal Neurological Institute. He hoped to cure epileptics (癫痫病人) by stimulating a part of their brains called the temporal cortex (脑的颞皮层) with a mild electric current. Because the brain is immune to pain, Penfield was able to operate with his patients fully awake. To his astonishment, simply by touching the brains of some patients with the tip of his wire-thin electrode (电极) he was able to evoke astonishingly precise and vivid memories. "I see a guy coming through the fence at the baseball game," exclaimed one patient, whenever Penfield touched the upper part of his left temporal lobe (脑叶). "It’s the middle of the game, and I’m back there watching him)" Another woman reported being back at a con cert she had once attended and could even hum along with the orchestra whenever her brain was stimulated.
Investigators using hypnosis (催眠术) have been as astonished as Penfield at the amazing capacity of our memories. Once in a trance (昏睡), good hypnotic subjects can report detailed recollections of events that took place days, months, even decades ago—which, when checked against old records and diaries, turn out to be accurate. "Everything, absolutely everything, is remembered," says one hypnotist.
Even senile patients, who can hardly remember recent events at all, retain the ability to remember new experiences, but only very briefly. "Give them a list of nonsense syllables to memorize, and for a few seconds they do almost as well as healthy young people in remembering," says one expert. But apparently the brains of senile subjects cannot electrochemically translate the new information and shift it into long-term storage. It seems rather as if our perceptions, in order to be remembered for more than a few seconds, must be sorted out and slid into place like folders into file cabinets. Some of the cabinets are easily opened, their contents readily available to us. Others, thanks to still unknown processes, are locked away, only to be retrieved if the files are jarred open by hypnosis or a researcher’s electrode.
For years, scientists hunted for the brain’s elusive "memory center," where long-term memories might be processed and stored. Above all, the hippocampi (侧脑室下角的海马状突起物), small, seahorse-shaped structures about three centimeters long, deep within each half of the brain, were target ed as the possible center. If one hippocampus is injured, memory is temporarily affected, then eventually returns. But if both are damaged, the loss of memory is final. Patients who have lost their hippocampi live in a strange, twilight world. If they meet you, they will shake your hand and five minutes later greet you as a complete stranger. Although they can still perform well enough on IQ tests and speak quite intelligently, it’s as if some crucial memory system had been cruelly short-circuited. Often they’re aware something is wrong and try to hold on to their memories. But the attempt is usually use less, and even when they forget the reason for their sadness, they remain de pressed.
Is it possible to improve your memory?
The surprising answer appears to be yes. Dr. Richard J. Wurtman, professor of endocrinology (内分泌学) at the Massachusetts Institute of Technology, recently discovered that the food we eat can affect the amount of neuro transmitters in our brains and—by implication—how well we can remember.
In 1985, Wurtman and his colleagues learned that choline (胆碱), a common food substance found in large quantities in egg yolks (and to some degree in meat and fish as well), has a pronounced effect on the brain’s ability to make an important neurochemical called acetylcholine (乙酰胆碱), al most certainly involved in memory.
Meanwhile, new information is being gathered about memory loss among older people. With the exception of an unfortunate minority who suffer from Alzheimer’s disease, a progressive ailment that leads to almost total memory loss, the news is good. "I think the most crucial thing we’ve learned is that it simply isn’t true that you lose your memory as you get older," says Dr. James Ninninger of the Payne Whitney Psychiatric Clinic. "That’s simply one of the self-fulfilling prophecies that should be dropped." At Johns Hopkins University, studies of men over many years as they grow older confirm this belief. "There are some subjects sixty-five to ninety who are just not showing any decrements," says Dr. Nathan Shock, who admits that the findings surprised him.
Although some brain changes do seem to come with age, in most cases their effect on memory is not nearly as serious as once thought. Even the idea that we begin to lose hundreds of thousands of brain cells each day past the age of 30 with the usual grim implication that our brainpower must diminish- has recently been hotly disputed. "As a neuroanatomist (神经解剖学家 ), I’ve been intrigued by this myth of disappearing brain cells," Dr. Mari an C. Diamond, professor of anatomy at the University of California at Berkeley, has said. As she points out, almost no studies of brain loss have been done in humans and only a few haphazard ones in animals. "In fact," she insists, "there is only a trivial decrease in the number of brain cells— right up through old age."
Another recent finding is that intellectual stimulation keeps memory at its peak—just as physical exercise does for our muscles. In the Johns Hopkins’ studies, the people who showed the least memory impairment as they aged were those who had made problem-solving a way of life. Studies in monkeys and rats have shown the same thing: constant mental activity pre serves memory. And at least until we reach the outer limits of old age, the continuous amount of new information we are always storing should help us to remember, not cause us to forget. Dr. Patricia Siple, a psychologist at the University of Rochester, has found that a large store of information helps our memories. We remember not so much words and sounds as concepts, which form a kind of indexed system to recall information.
Recent research indicates that, unlike a container that can be filled, our memory far more resembles an ever-growing tree, continually putting out new roots and connections, memory building on memory, rivaled in complexity only by the mysterious, ever-challenging brain itself.
Recent findings also indicate that ______ helps us keep memory at its height.
选项
答案
constant intellectual stimulation
解析
转载请注明原文地址:https://kaotiyun.com/show/I97K777K
0
大学英语六级
相关试题推荐
ThestudyfoundthatcigarettesmokingamongAmerican【36】______droppedduringthepastyear.Thedropcontinuesageneraldecre
Directions:Inthispart,youwillhave15minutestogooverthepassagequicklyandanswerthequestionsonAnswerSheet1.Fo
Directions:Inthispart,youwillhave15minutestogooverthepassagequicklyandanswerthequestionsonAnswerSheet1.Fo
THEBLENDINGOFTHEUNITEDSTATESForyears,JorgeDelPinal’sjobasassistantchiefoftheCensusBureau’sPopulationDivi
THEBLENDINGOFTHEUNITEDSTATESForyears,JorgeDelPinal’sjobasassistantchiefoftheCensusBureau’sPopulationDivi
A、12:15.B、1:10.C、1:00.D、12:30.C在听懂全部对话的基础上,要格外留心其中提及的时间:aquarterafter12和45minutes,可边听边记,并理解问题中departure的含义是离开,scheduled含
MildweatherhasbroughtJapan’smuch-lovedcherrytreesinto【B1】______twoweeksearlythisyear,butnoteveryoneis【B2】__
MildweatherhasbroughtJapan’smuch-lovedcherrytreesinto【B1】______twoweeksearlythisyear,butnoteveryoneis【B2】__
MildweatherhasbroughtJapan’smuch-lovedcherrytreesinto【B1】______twoweeksearlythisyear,butnoteveryoneis【B2】__
随机试题
变压器作空载试验,要求空载电流一般在额定电流的()左右。
在催收应收账款时,常用的策略有:①信函通知;②派员面谈;③诉诸法律;④电告催收。催收的程序一般是()
社会主义初级阶段基本路线的核心和主体是()
关于胎盘早期剥离,不正确的是
A、奶瓶龋B、少年龋C、猖獗性龋D、环状龋E、忽视性龋突然发生广范围快速的龋怏-,很快发生牙髓感染,下颌乳前牙也受到龋蚀的侵及
A.病因诊断B.病理解剖诊断C.病理生理诊断D.并发症的诊断E.伴发病的诊断乙型病毒性肝炎的诊断依据是
材料一:近日,国务院办公厅印发《完善促进消费体制机制实施方案(2018-2020年)》,其中提出:大力发展住房租赁市场。总结推广住房租赁试点经验,加快研究建立住房租赁市场建设评估指标体系。发挥国有租赁企业对市场的引领、规范、激活和调控作用,支持专
A、B两条船分别从甲港开往乙港,已知A船经过中点时B船刚走了全程的,A船到达终点时,B船恰走到中点。若两船各自速度始终不变,A船10点从甲出发11点抵达乙港.则B船几点出发?
公共危机管理是现在经常被提起的话题。在社会公共事件频发的今天,如何提高政府的公共危机管理能力是各级政府经常探讨的话题。2014年3月1日,昆明一伙歹徒持械冲进昆明火车站广场、售票厅,见人就砍,现场有人伤亡;歹徒手持刀具、统一着装;10多辆警车赶赴现场抓捕
一个具有m个结点的二叉树,其二叉链表结点(左、右孩子指针分别用left和right表示)中的空指针总数必定为(57)个。为形成中序(先序、后序)线索二叉树,现对该二叉链表所有结点进行如下操作:若结点p的左孩子指针为空,则将该左指针改为指向p在中序(先序、后
最新回复
(
0
)