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
57
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.
How does the brain function according to the old view?
选项
A、The traces of memory are made in an area called hippocampus.
B、The hippocampus stores long-term memory.
C、The hippocampus is located behind the forehead.
D、The information is stored in only the hippocampus, not in cerebral cortex.
答案
D
解析
推理题。此题题干的问题可以在第五段开头找到,但是答案却要看回第四段,这是上段说明下段来总结的例子,答案可以在“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 codex.”推断得出D。其他三个选项有提及,但均不是题干答案内容。
转载请注明原文地址:https://kaotiyun.com/show/wkaO777K
0
专业英语八级
相关试题推荐
Whentheendoftheworldcomes,we’llknowwhattoblame.ScientistshavefoundcompellingevidencethattheSunhasababybro
TherenownedAmericanlinguistN.Chomskyinthelate1950’sproposedthedistinctionbetween______.
IntheUnitedStates,charterschoolsprovidealternativesto"regular"publicschools.Unlikemostpublicschools,chartersdon
TheAmericanFamilyWe’lllearntheAmericanfamiliesfromthefollowingfiveaspects:1.Familystructures1)Immediatefamily
Deathisasubjectthatisevaded,ignored,anddeniedbyouryouth-worshipping,process-orientedsociety.Itisalmostasweh
BodySystemsAbodysystemreferstoagroupoforgans,whicharepartsofthebodythatdoaspecialjob,suchastheheart,
ThefirstwriterinAmericatowintheNobelPrizeinliteratureis______.
DanielDefoeisafamous______.
CarrieMeeberappearsin______.
Culturereferstothesocialheritageofapeople—thelearnedpatternsforthinking,feelingandactingthatcharacterizea
随机试题
CharlotteHollinsknowsshefacesabattle.The23-year-oldBritishfarmerandher21-year-oldbrotherBenarefightingtosave
27岁初产妇,妊娠38周。今晨起床时发现阴道流血,量中等,无明显腹痛及宫缩。可以确诊本病的体征是
下列关于胃癌根治切除术的叙述,正确的是()
下列关于凝胶剂叙述正确的是()。
某实施监理的机电工程项目,在基础施工时,施工人员发现了有研究价值的古墓,监理机构及时采取措施并按有关程序处理了该事件。设备安装工程开始前,施工单位依据总进度计划的要求编制了如图7-1所示的设备安装双代号网络进度计划(时间单位:天),并得到了总监理工
患者,男,60岁,胆石症多年,2天前腹痛,寒战、高热和黄疸发作,经抗生素治疗无效,1小时前患者意识不清,血压80/60mmHg。应考虑()。
很久以前,一位挪威青年男子漂洋到法国,他要报考巴黎音乐学院。考试的时候尽管他竭力将自己的水平发挥到最佳状态,但还是未被录取。作者接下来最有可能主要介绍的是()。
12月7日,记者从山西高平市文物旅游局获悉,11月19--23日,在高平市羊头山上,省文物考古研究所专家发现一处仰韶文化遗址。遗址上,除发现大量陶片、瓦砾外,还发掘出一道东西走向的人工石砌围墙、石基础、古旧步道,经山西省考古研究所考古专家推测,这处遗址可能
以下有关财务杠杆的说法正确的是()。
Look,______inhisusualT-shirt.
最新回复
(
0
)