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  3. Think about yesterday’s lunch and a variety of details may leap to mind, each of them employing a different section of your brai

Think about yesterday’s lunch and a variety of details may leap to mind, each of them employing a different section of your brai

admin2015-03-25  4
问题     Think about yesterday’s lunch and a variety of details may leap to mind, each of them employing a different section of your brain. The olfactory system calls up what the meal smelled like, while the visual cortex retrieves images of the restaurant you ate in and the temporal lobe recalls the sound of your waitress’s voice. Scientists have long suspected that every recollection— from the mundane to the momentous—ignites a distinct pattern of neurons. But for decades, they have struggled to understand how the brain assembles such disparate elements into a single coherent memory, one that can be retrieved intact, spontaneously or on demand, hours, days or even years after the fact. "It’s not like a tape recorder where you store it all on one cassette," says Lynn Nadel, a neuroscientist at the University of Arizona in Tucson. "There’s more than one PLAY button to hit. "
    It’s no trivial matter. One of the most devastating effects of dementia and Alzheimer’s disease is the loss of what’s known as episodic memory—the capacity to remember experiences in detail. Despite years of research and some initial progress, the ability to restore this function to aging or diseased brains continues to elude doctors. But research published earlier this month in the journal Science has provided some important clues into how the brain builds memories.
    UCLA neuroscientist Itzhak Fried and his Israeli colleagues measured neural activity in the brains of 13 study participants as they watched short video clips. Afterward, while their brains were still being monitored, subjects were asked to describe whichever of the video clips came to mind. The same neurons that had fired as they watched a given clip fired again when they recalled that clip. Actually, researchers could predict which clip a subject was about to remember, as corresponding neurons flared up seconds ahead of actual remembering.
    The findings offer the first proof of a long-held assumption—reactivation of the neurons initially involved in an experience forms the basis of human memory. " Being able to see human memory recall in action, in real time, is unprecedented," says MIT neuroscientist Matthew Wilson. "We’ve suspected for quite a while storage and retrieval would be concentrated in the same cells, but never had the proof until now. "
    As exciting as that finding may be, however, some memory experts say the true significance of Fried’s study lies not in when the neurons fired, but in where they were located—the hippocampus. One of the earliest and most common signs of Alzheimer’s disease is patients start getting lost in places familiar to them. The hippocampus, a thin slice of tissue tucked deep in the brain, is known to play a role in the ability to remember and navigate through a given place, a process known as spatial learning. The involvement of these same cells in the storage and retrieval of memories suggests location may be the key to human recollections, the defining element summoning all the other elements together to reconstruct an event.
According to the passage, which of the following statements is true?
选项 A、Whether people can recall the details of yesterday’s lunch is a trivial matter.
B、After years of research, doctors made initial progress in restoring episodic memory.
C、What’s published in Science this month is carried out by Fried and his colleagues.
D、Some experts think the discovery of when neurons work in Fried’s study is useless.
答案C
解析 推理判断题。解答本题可以用排除法：[A]与第二段首句意思不符，故排除；[B]与第二段第三句“医生们仍无法恢复老化或者生病大脑的这一功能”相悖；根据最后一段第一句可知，一些记忆专家认为弗里德研究最重要之处不在于神经元何时工作，而在于神经元所处的位置，这意味着那些专家否定了关于神经元何时工作的重要性，但并没有完全否定其价值，因此[D]不正确。第二段末句提到了在《科学》杂志上发表了一项研究，第三段紧接着介绍Fried与其同事的研究，由此可以推断，杂志上的研究与后者的研究是同一项，故正确答案是[C]。
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