Roadside bombs, childhood abuse, car accidents—they form memories that can shape(and damage)us for a lifetime. Now, a handful of

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问题     Roadside bombs, childhood abuse, car accidents—they form memories that can shape(and damage)us for a lifetime. Now, a handful of studies have shown that we’re on the verge of erasing and even rewriting memories. The hope is that this research will lead to medical treatments for mental disease, especially for addiction and post-trauma tic stress disorder(PTSD).
    Researchers have known for decades that memories are unreliable. They’re particularly adjustable when actively recalled because at that point they’re pulled out of a stable molecular state. A study was performed at the University of Washington in which adult volunteers completed a survey about their eating and drinking habits before age 16. A week later, they were given personalized analyses of their answers that stated—falsely—that they had gotten sick from rum or vodka as a teen. One in five not only didn’t notice the lie, but also recalled false memories about it and rated that beverage as less desirable than they had before.
    Studies like these point to possible treatments for mental health problems. Both PTSD and addiction disorders hinge on memories that can trigger problematic behaviors, such as crippling fear caused by loud noises or cravings brought about by the sight of drug paraphernalia(用具).
    Several studies have found chemical compounds that can be used to subdue or even delete memories in mice(and maybe someday in people). In June, a report led by an Emory University researcher showed that SR-8993, a drug that acts on the brain’s opioid receptors, can prevent a fear memory from forming. Researchers strapped mice to a wooden board for two hours—a stressful experience that later gave them a heightened sense of fear similar to PTSD. But mice given SR-8993 before or after the stressful incident were less likely to end up this way.
    Another study identified a drug, Latrunculin A, that can erase memories days later. The researchers trained mice to consume methamphetamine(甲基苯丙胺,俗称“冰毒”)in an environment with distinctive visual, tactile, and scent cues such as black walls, gridded floors. Mice that were injected with Latrunculin A two days later didn’t seek out meth when returned to that environment, but others did.
    To make more targeted treatments, researchers will ultimately need to understand how the brain’s neurons encode each memory. Susumu Tonegawa at the Massachusetts Institute of Technology reported that individual memories in mice leave telltale molecular signatures in the brain’s hippocampus(海马体)region. Later, his group caused mice to falsely associate an old memory with a new context—essentially creating a false memory.
    The idea of scientists manipulating memory does, naturally, sound a bit creepy. But it also points to some possible good: treatment for millions of people tormented by real memories. And that’s something worth remembering.
According to Susumu Tonegawa’s research, why people can have a false memory?

选项 A、Because a false memory can really leave marks in the brain.
B、Because a real memory can be easily removed by a false one.
C、Because the brain’s neurons can convert a real memory into a false one.
D、Because an old memory, combined with a new situation, can change into a false one.

答案D

解析 细节辨认题。由定位句可知,Susumu Tonegawa教授和他的研究团队能够让受试老鼠在旧记忆和新场合之间建构联系,从而创造出一个虚假的新记忆。由此可以推断,人类之所以也能产生虚假记忆是因为旧记忆和新场合相融合的缘故,故答案为D)。本段第二句指出,在大脑海马区留下分子记号的是个体真实记忆,而非虚假记忆,故A)“虚假记忆在大脑中留下印记”错误;本段最后一句指出,旧记忆与新场合联系可以形成虚假记忆,而非“真实记忆能够轻易地被虚假记忆抹去”,故B)错误;本段第一句中谈到,大脑神经元的作用是将每个记忆编码,而非“将一个真实记忆转换成一个虚假记忆”,故C)错误。
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