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
Scientists have long believed that constructing memories is like playing with neurological toys. Exposed to a barrage of sensati
Scientists have long believed that constructing memories is like playing with neurological toys. Exposed to a barrage of sensati
admin
2012-12-30
43
问题
Scientists have long believed that constructing memories is like playing with neurological toys. Exposed to a barrage of sensations from the outside world, we connect together brain cells to form new patterns of electrical connections that stand for images, smells, touches and sounds.
The most unshakable part of this belief is that the neurons used to build these memory circuits are depletable resource, like petroleum or gold. We are each given a finite number of cells, and the supply gets smaller each year. That is certainly how it feels as memories blur with middle age and it gets harder and harder to learn new things. Maybe it’s time for this notion to be forgotten-or at least radically revised.
In the past two years, a series of confusing experiments has forced scientific researchers to rethink this and other assumptions about how memory works. The perplexing results of these experiments remind scientists how much they have to learn about one of the last great mysteries-how the brain keeps a record of our individual passage through life, allowing us to carry the past inside our head.
This much seems clear: the traces of memory-or engrams as neuroscientists call them-are first forged deep inside the brain in an area called the hippocampus. This area stores the engrams temporarily until they are transferred somehow (perhaps during sleep) to permanent storage sites throughout the cerebral cortex. This area, located behind the forehead, is often described as the center of intelligence and perception. Here, as in the hippocampus, the information is thought to reside in the form of neurological scribbles, clusters of connected cells.
Until now our old view of brain functionality has been that these patterns ate constructed from the supply of neurons that have been in place since birth. New memories don’t require new neurons-just new ways of connecting the old ones together. Retrieving a memory is a matter of activating one of these circuits, coaxing the original stimulus back to life.
The picture appears very sensible. The billions of neurons in a single brain can be arranged in countless combinations, providing more than enough clusters to record even the richest life. If adult brains were cranking out new neurons as easily ad skin and bone from new cells, it would serve only to scramble memory’s delicate ornamental pattern.
Studies with adult monkeys in the mid-1960s seemed to support the belief that the supply of neurons is fixed at birth. Therefore the surprise when Elizabeth Gould and Charles Gross of Princeton University reported last year that the monkeys they studied seemed to be producing thousands of new neurons a day in the hippocampus of their brain. Even more surprising, Gould and Gross found evidence that a steady stream of the fresh cells may be continually moving to the cerebral cortex.
No one is quite sure what to make of these findings. There had already been hints that spawning of brain cells, a process called neurogenesis, occurs in animals with more primitive nervous systems. For years, Fernando Nottebohm of Rockefeller University has been showing that canaries create a new batch of neurons every time they learn a song, then slough them off when it’s time to change tunes.
But it was widely assumed that in mammals and especially primates this manufacture of new brain parts had long ago been phased out by evolution. With a greater need to store memories for a long time, these creatures would need to ensure that the engrams weren’t disrupted by interloping new cells.
We used to think that the neurons______.
选项
A、need to be constructed in new patterns to store the new information
B、can be arranged to forge countless new cells to record information
C、can be produced easily as skin and bone grow new cells
D、all of above
答案
A
解析
此题为细节题。作答此题要看清楚题干,“We used to think that the neurons…”即“我们曾认为神经元……”的意思,言下之意就是我们原来的想法是不对的,所以,答此题最后用排除法,回原文第六段“The billions of neurons in a single brain can be arranged in countless combinations, providing more than enough clusters to record even the richest life.If adult brains were cranking out new neurons as easily ad skin and bone from new cells.”涵盖了BC的说法,D说包含上述三项自然也不对,所以,很容易就选出了A正确答案。
转载请注明原文地址:https://jikaoti.com/ti/cdUYFFFM
0
专业英语八级
相关试题推荐
IntheUnitedStates,charterschoolsprovidealternativesto"regular"publicschools.Unlikemostpublicschools,chartersdon
______isthekeyconceptioninChristianityinwhichthethreeaspectsofthesameGodareunitedasone.
Duringthewholeofadull,dark,andsoundlessdayintheautumnoftheyear,whenthecloudshungoppressivelylowintheheav
Deathisasubjectthatisevaded,ignored,anddeniedbyouryouth-worshipping,process-orientedsociety.Itisalmostasweh
WiththeexplosionofexcitementabouttheInternet,thereseemstobeanothertypeofaddictionthathasinvadedthehumanpsyc
Thewordsthatcontainonlyonemorphemearecalled______.
CarrieMeeberappearsin______.
书籍到了我的手里,我的习惯是先看序文,次看目录。页数不多的往往立刻通读,篇幅大的,只把正文任择一二章节略加翻阅,就插在书架上。除小说外,我少有全体读完的大部的书,只凭了购入当时的记忆,知道某册书是何种性质,其中大概有些什么可取的材料而已。什么书在什么时候再
1925年2月24日,国父孙中山病危时,留下一段《家事遗嘱》:“余因尽瘁国事,不治家产。其所遗之书籍、衣物、住宅等均付吾妻宋庆龄,以为纪念。余之儿女已长成能自立,望各自爱,以继余志。此嘱。”中山先生艰苦奋斗40年,功勋卓然。但终身廉洁,
随机试题
如果“新龙门”餐馆在同一天供应红焖羊肉和什锦火锅,那么它也一定供应烤乳猪,该餐馆星期二不供应烤乳猪。贾女士只有当供应红焖羊肉时才去“新龙门”餐馆吃饭。如果上述断定是真的,那么以下哪项也一定是真的?
简述PHP语言的特点。
清代负责寄递外务部与驻外使馆间的往来公文的秘书性机构是
Youhavestudiedhard,andthedayhas【C1】______comewhenyoumustwriteyourexam.Trytoarriveafewminutesbeforethe【C2】__
湿热、瘀热蕴久成毒或直接感受湿、热、毒邪,宜清热解毒,代表方剂有
根据民事诉讼法律制度的规定,书记员的回避应当由()决定。
自魏晋以来,在玄学思潮的推动下,开创了在文学创作中追求言外之意、弦外之音、象外之趣以及言有尽而意无穷的美学旨趣。中国古代诗歌理论对此有大量论述,这是众所周知的。下列古诗文语句中,不符合这种审美旨趣的是()。
根据下列材料回答下列问题。下列说法中错误的是()。
求由方程xyz+(其中z小于0)所确定的函数z=z(x,y)在点(1,0)处的全微分dz.
微分方程y"-3y'+2y=2ex满足的特解为__________________.
最新回复
(
0
)