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
88
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.Youwillhearamandiscussinganorderfromanofficesupplycompany.For
Asaresultofthelightingsystem,people______.
Paymenttobemadebycashondelivery.TheinvoicehastobepaidForestryuniversitystudentsbycitizenship.Whichcountry
Mindyourhead.Delegatesareaskedtocheckoutby10:30a.m.Thedelegatesshouldleavetheirrooms.
•Lookatthenoticebelow.ItshowsthecompanieswithofficesintheRoyalCommercialbuilding.•Forquestions6-10,decidewhi
TRAININGOPPORTUNITIESFORLOCALBUSINESSESAseriesof15one-daycoursesisbeingplannedforsmallbusinessesintheScar
TheInspironAndTheOthersDELLINSPIRONnotebooksaredesignedforsmallbusinesseswhichdemandbetterperformanceandmor
Creasey’sOfficeSupportAbroadrangeofsmallbusinessservicesprovidedbyaworkforcewithcombinedexperienceofover45ye
Readthetextbelowaboutasportsretailer.ChoosethecorrectwordtofilleachgapfromA,BorContheoppositepage.Fore
Lookatthelistbelow.Itshowsanumberofbusinesstrainingcourses.Forquestions6-10,decidewhichtrainingcourse(A-H)ea
随机试题
东亚市场包括()
黏膜纤毛清除功能显像的检查方法,下列哪项是不准确的
下列关于卵巢癌的说法不正确的是
某个体医师,在一次诊治中不按照规定使用麻醉药品,受到责令暂停6个月执业活动的行政处罚,随后又被注销注册,他对后一处理特别不满,可以依法采取的法律救助是
A、Vj=150.26kNB、Vj=134.91kNC、Vj=123.67kND、Vj=118.05kNB
在泵送混凝土的原材料和配合比中应注意,粗骨料宜优先选用( )。
合伙事务执行人不按照合伙协议或全体合伙人的决定,与善意第三人以合伙企业的名义进行商业行为的,以下说法符合合伙企业法的是()。
已知a,b,c,均为正数,且a<c,b<c,=1,若以a,b,c为三边构造三角形,则c的取值范围是__________。
唐三彩是一种盛行于清代的陶器,以黄、白、黑色为基本釉色。()
Publicofficialsandcandidatesforpublicofficeroutinelyusepublicopinionpollstokeeptrackofwhatthepeoplearethinki
最新回复
(
0
)