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Sleep Necessary for Memories

Burning the midnight oil before an exam or interview does harm to the performance according to a recent research which found that sleep is necessary for memories to be taken back into the brain. A．good night’s sleep within 30 hours of trying to remember a new task is a required condition of having good recall in the weeks ahead, scientists have found.
The research, published in the December issue of Nature Neuroscience, showed that it was the act of sleep, rather than the simple passage of time, that was critical for long- term memory formation.
"We think that getting that first night’s sleep starts the process of memory consolidation (巩固)," said Robert Stickgold, a sleep researcher at Harvard Medical School who conducted the latest study.
"It seems that memories normally wash out of the brain unless some process nails them down. My suspicion is that sleep is one of those things that does the na
A. couldn’t remember the task.
B. could not sleep the second and third nights.
C. performed slightly better than those who did not.
D. did much better than those who did not.