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 he 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 nailing down," Professor Stickgold said.
With about one in five people claiming that they are so chronically short of
sleep that it affects their daily activities, the latest work emphasizes the
less well-understood side effect—serious memory impairment (损害).
Volunteers in an experiment found it easier to remember a memory task if
they were allowed to sleep that night. But for those kept awake, no amount of
subsequent sleep made up for the initial loss. Professor
Stickgold’s team trained 24 people to identify the direction of three diagonal
(斜线形的) bars flashed for a sixtieth of a second on a computer screen full of
horizontal (水平的) stripes. Half of the subjects were kept awake
that night, while the others slept. Both groups were allowed to sleep for the
second and third nights to make up for any differences in tiredness between the
volunteers. Those who slept the first night were significantly
and consistently better at remembering the task while the second group showed no
improvement despite enjoying two nights of catch-up sleep. The research published in Nature Neuroscience showed that what was
essential to the formation of long-term memory was ______.