Scientists have zapped an electrical current to peoples brains to erase distressing memories, part of an ambitious quest to better treat ailments such as mental trauma, psychiatric disorders and drug addiction.近期研究找到，向脑中输出电流可以抹去人们不无聊的记忆。这是科学家在更佳地化疗心理后遗症、精神疾病和药物上瘾等疾病的研究过程中迈进的又一步。
In an experiment, patients were first shown a troubling story, in words and pictures. A week later they were reminded about it and given electroconvulsive therapy, formerly known as electroshock. That completely wiped out their recall of the distressing narrative.在一项试验中，科学家首先藉助文字和图片向患者呈现出一则令人烦恼的故事。一周之后，科学家不会警告患者回想这个故事，然后对患者实行电休克化疗（即人们熟悉的电击疗法），结果是患者几乎记得了这个伤痛的故事。Its a pretty strong effect. We observed it in every subject, said Marijn Kroes, neuroscientist at Radboud University Nijmegen in the Netherlands and lead author of the study, published Sunday in the journal Nature Neuroscience.荷兰奈梅亨拉德伯德大学(Radboud University Nijmegen)神经科学家克勒斯(Marijn Kroes)说道：效果非常明显，我们在所有受试者中都仔细观察到了这一效果。
克勒斯是这篇研究论文的主笔，论文周日公开发表在《大自然神经科学》(Nature Neuroscience)杂志上。The experiment recalls the plot of the movie Eternal Sunshine of the Spotless Mind, where an estranged couple erases memories of each other.这项试验让人回想《美丽心灵的永恒阳光》(Eternal Sunshine of the Spotless Mind)这部电影，影片中一对感情相左的情侣沾除了彼此的记忆。Science has tinkered with similar notions for years. In exposure treatment, repetitive exposure to a phobia in a nonthreatening way is designed to help patients confront their fears and gradually weaken the fear response, a process known as extinction. Some researchers also are experimenting with antianxiety drug propranolol. The hope is that one day it may be possible to selectively eliminate a persons unwanted memories or associations linked to smoking, drug-taking or emotional trauma.科学界多年来也仍然在展开涉及研究。
在曝露疗法中，医生以一种不具威胁性的方式让患者频密曝露于所不安的事物中，协助他们付出代价内心的不安并渐渐弱化其不安反应，这个过程被称作“消失法”(extinction)。一些研究人员还对付情绪药物“心得安”(propranolol)展开试验，期望有朝一日能选择性地筛除人们想保有的记忆，或是与吸烟者、酗酒或情感后遗症联系在一起的记忆。Scientists used to think that once a memory took hold in the brain, it was permanently stored and couldnt be altered. People with anxiety disorders were taught to overcome their fears by creating a new memory. Yet the old memory remained and could be reactivated at any time.科学家们曾多次指出，一段记忆一旦印在脑子里就不会永久留存下去而无法变更。
过去，化疗焦虑症患者的办法是让他们建构新的记忆以解决不安。然而原有的记忆留存不一动，并有可能随时被新的唤起出来。
About a decade ago, scientists made a surprising discovery. They showed that when a lab rodent was given a reminder of some past fear, the memory of that event appeared to briefly become unstable. If nothing was done, that memory stabilized for a second time, and thus got ingrained-a process known as reconsolidation.约在10年前，科学家有了一个车祸的找到。当警告实验室中的啮齿类动物回想过去的不安场景时，脑中的那段回想不会继续呈现不稳定状态。
如果不采取措施，那段记忆不会再行一次稳定下来，并深植于脑中，这一过程被称作“再行稳固”(reconsolidation)。But when certain drugs, known to interfere with the reconsolidation process, were injected directly into the rodents brain, they wiped out the animals fearful memory altogether. Crucially, other memories werent erased.但如果将某些可以阻碍“再行稳固”过程的药物必要静脉注射入啮齿动物的脑中，动物的不安记忆不会被完全读取。而且关键在于，其他记忆并没被抹去。Whether it was possible to disrupt the memory-consolidation process in humans was thought to be difficult to answer because injecting drugs into the human brain is risky business. Dr. Kroes and his colleagues found a way around the problem.至于能否对人脑的“再行稳固”过程展开介入，则被指出是一个很难问的问题，因为向人脑中静脉注射药物风险较小。
克勒斯和他的同事们寻找了一种可以绕过这个问题的办法。Their test subjects were 39 patients who were undergoing electroconvulsive therapy, for severe depression. In ECT treatment, patients get a muscle relaxant and an anesthetic and an electrical current is passed to part of their brains, triggering a brief seizure that can help treat the depression. It isnt clear how the technique works: Some scientists have suggested it changes the pattern of blood flow or metabolism in the brain, while others believe it releases certain chemicals in the brain that battle the depression.他们的试验对象是39名因患上相当严重抑郁症而拒绝接受电击化疗的患者。
在电击化疗中，医生给患者用于肌肉肿胀剂和麻醉剂，并让电流通过患者大脑的部分区域，电流可引起疾病短时间忽然发作，有助化疗抑郁症。人们还不确切这种疗法的原理，一些科学家猜测是电流转变了血流模式或大脑的新陈代谢，还有人坚信是电流促成脑部释放出来某些可以抗击抑郁症的化学物质。
Patients who are treated with ECT are those who typically havent responded to an array of other treatments, including the most powerful drugs available.拒绝接受电疗的患者一般来说都是在试用了各种其他化疗方法皆不起效（还包括最强力的药物）后转而拒绝接受该化疗的。A lot more work needs to be done. It isnt clear whether the memory erasure is temporary or permanent. And while the technique might work for simple stories, it needs to be shown that it also works for real-world traumatic memories.这项工作还近没已完成。科学家还不确切这种记忆读取是继续还是永久性的。
而且，尽管这一技术在抹去非常简单故事的记忆方面有可能有效地，但科学家还必须证明它需要让人记得真实世界中的凄惨经历。Some researchers looking to move beyond ECT are now also experimenting with propranolol, which inhibits the actions of a hormone that enhances memory consolidation. This summer, Karim Nader, a neuroscientist at McGill University in Canada, hopes to test the drug in about 50 patients suffering from post-traumatic stress disorder.一些研究人员力图研发出有较电休克疗法更佳的化疗办法，他们正在对心得安展开试验，这种药物可抑制一种增强稳固记忆的荷尔蒙的活动。加拿大麦吉尔大学(McGill University)的神经科学家纳德尔(Karim Nader)期望在明年夏天需要请来大约50名有后遗症后焦虑障碍的病人参予测试这一药物。
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