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
78
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.YouwillhearareportonIndianeconomy.Foreachquestion(16-22),filli
Youwillhearaconversationthroughaphone.Foreachquestion(23-30),markoneletter(A,BorC)forthecorrectanswer.After
Youwillhearaconversationthroughaphone.Foreachquestion(23-30),markoneletter(A,BorC)forthecorrectanswer.After
Thecustomercan’thavearefundbecause
Readthemessagefromyoursecretary.TelephoneMessageMr.Wangcalledtosaythathewaspromo
YouwanttheseniorSecretaryintheGeneralOfficetoordersomeofficeequipment.Youneedaportablecomputer,acarryingcas
Readthisnoteyouhavereceivedfromyourboss.MaryBrownatHeadOfficecalledtoinvitestafffromourbranchtohavea
BUSINESSCOURSESAHospitalityandTourismManagementBMarketingResearchCProductDesignandDevelopmentDMarketingandElec
推进现代化建设、完成祖国统一、维护世界和平与促进共同发展,是中国人民在新世纪的三大历史任务。
随机试题
A.去枕平卧6~8小时B.平卧可不去枕C.半坐卧位D.侧卧位E.俯卧位
里证形成的主要原因是
对哮喘持续状态伴阵发性心动过速的患者,哪项治疗措施是错误的
眼眶手术、手术进路原则为
A.白细胞减少症B.再生性障碍贫血C.缺铁性贫血D.白血病E.淋巴瘤全血细胞减少,网织红细胞减少,为
暂估材料或工程设备的单价确定后,在综合单价中只应取代原暂估单价,不应再在综合单价中涉及某些其他费的变动,这些费用是指()。
证券交易种类通常根据交易对象来划分,那么证券交易可分为()
烂尾楼
《礼记》中有言:“君子乐得其道,小人乐得其欲。”下面几种说法最能说明这句话含义的是
在查询设计器"添加表和视图"窗口中,单击"其他"按钮用于添加:
最新回复
(
0
)