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
In patients with Huntington’ s disease, it’ s the part of the brain called the basal ganglia that’ s destroyed. While these vict
In patients with Huntington’ s disease, it’ s the part of the brain called the basal ganglia that’ s destroyed. While these vict
admin
2011-01-26
74
问题
In patients with Huntington’ s disease, it’ s the part of the brain called the basal ganglia that’ s destroyed. While these victims have perfectly intact explicit memory systems, they can’ t learn new motor skills. An Alzheimer’ s patient can learn to draw in a mirror but can’ t remember doing it: a Huntington ’ s patient can’ t do it but can remember trying to learn. Yet another region of the brain, an almond-size knot of neural tissue seems to be crucial in forming and triggering the recall of a special subclass of memories that is tied to strong emotion, especially fear. These are just some of the major divisions. Within the category of implicit memory, for example, lie the subcategories of associative memory--the phenomenon that famously led Parlov’ s dogs to salivate at the sound of a bell which they had learned to associate with food--and of habituation, in which we unconsciously file a way unchanging features of the environment so we can pay closer attention to what’ s new and different upon encountering a new experience.
Within explicit, or declarative memory, on the other hand, there are specific subsystems that handle shapes, textures such as faces, names--even distinct systems to remember nouns vs. verbs. All of these different types of memory are ultimately stored in the brain’ s cortex, within its deeply furrowed outer layer--a component of the brain dauntingly more complex than comparable parts in other species. Experts in brain imaging are only beginning to understand what goes where, and how the parts are reassembled into a coherent whole that seems to be a single memory is actually a complex construction. Think of a hammer, and your brain hurriedly retrieves the tool’s name, its appearance, its function, its heft and the sound of its clang, each extracted from a different region of the brain. Fail to connect person ’ s name with his or her face, and you experience the breakdown of that assembly process that many of us begin to experience in our 20s and that becomes downright worrisome when we reach our 5Os.
It was this weakening of memory and the parallel loss of ability to learn new things easily that led biologist Joe Tsien to the experiments reported last week. "This age-dependent loss of function." he says, "appears in many animals, and it begins with the onset of sexual maturity."
What’ s happening when the brain forms memories--and what fails with aging, injury and disease--involves a phenomenon know as "plasticity". It’s obvious that something in the brain changes as we learn and remember new things, but it’ s equally obvious that the organ doesn ’ t change its overall structure or grow new nerve cells wholesale. Instead, it’ s the connections between new cells and particularly the strength of these connections that are altered by experience. Hear a word over and over, and the repeated firing of certain cells in a certain order makes it easier to repeat the firing pattern later on. It is the pattern that represents each specific memory.
We can draw a conclusion from the passage that ______.
选项
A、scientists have found the mechanism underlying the memorizing activities
B、more research must be done to determine the brain structure.
C、some researchers are not content with the findings.
D、it is obvious that something in the brain changes as we learn and remember
答案
A
解析
文中详细叙述了两种记忆机制的涵盖范围,以及功能等,可以判断选项A正确,即科学家们已找到了大脑活动机制。
转载请注明原文地址:https://kaotiyun.com/show/e2BO777K
0
考博英语
相关试题推荐
Lookatthenotesbelow.Someinformationismissing.Youwillheartwopeopletalkingaboutresume.Foreachquestion(9-15),fi
YouwillhearadialoguebetweenamanandHRManager.Foreachquestion(23-30),markoneletter(A,BorC)forthecorrectanswe
Thecustomercan’thavearefundbecause
●Readthismessagefromyoursecretary.TelephoneMessageMr.Smithcalled--sampleofshirtsnot
WehaveachainofsupermarketsalloverBritain.Imanagethelocalsportscenter.
•Readthearticlebelowaboutteam-building.•Choosethecorrectwordtofilleachgap,fromA,BorConthenextpage.•For
LeadingtheStrategicChangesTheleaderisthechangestrategist,whoseroleistolead,tochampionthechanges,topromot
WelcometotheDanseBankGroup’sjobsite.Thisiswhereyoucansearchforjobsanddiscoveraworkplacewithmorethan20,000
当前,国际形势正经历着自冷战结束以来最复杂、最深刻的变化。和平与发展依然是摆在世界各国人民面前的两大课题。和平是发展的前提,发展是和平的保障,在和平的环境中谋求发展已成为国际社会的共同愿望。
随机试题
设由抛物线y=x2与y=2-x2所围成的平面图形,试求:此平面图形的面积;
患者,女,68岁。CT表现:直肠壁局限性增厚,外壁毛糙,周围脂肪内见密度增高的结节影,周围筋膜增厚,拟诊为直肠癌,根据Thoeni分期应属于
机体排斥微生物侵袭的能力属于下列哪一种免疫功能
关于子宫的解剖,下列哪项是错误的( )
下述使用阿托品解救有机磷中毒的注意事项中,正确的是()。
业主主供应的材料、设备使用前,负责检验或试验的人和承担检验或试验费用的人分别是()。
Youcancloseyourumbrella.Therainseems______.
20世纪60、70年代我国成功试射“两弹一星”表明,中国在尖端科技领域的某些方面正接近世界先进水平,其中“两弹”是指()
设f(x)在(一∞,+∞)上有定义,x0≠0为函数f(x)的极大值点,则().
Intheworldofentertainment,TVtalkshowshaveundoubtedlyfloodedeveryinchofspaceondaytimetelevision.Andanyonewho
最新回复
(
0
)