To sleep. Perchance to file? Findings
published online this week by the Proceedings of the National Academy of
Sciences further support the theory that the brain organizes and stows memories
formed during the day while the rest of the body is catching zzz's.
Gyorgy Buzsaki of Rutgers University and his colleagues analyzed the
brain waves of sleeping rats and mice. Specifically, they examined the
electrical activity emanating from the somatosensory neocortex (an area that
processes sensory information) and the hippocampus, which is a center for
learning and memory. The scientists found that oscillations in brain waves from
the two regions appear to be intertwined. So-called sleep spindles (bursts of
activity from the neocortex) were followed tens of milliseconds later by beats
in the hippocampus known as ripples. The team posits that this interplay between
the two brain regions is a key step in memory consolidation. A second study,
also published online this week by the Proceedings of the National Academy of
Sciences, links age-associated memory decline to high glucose levels.
Previous research had shown that individuals with diabetes suffer from
increased memory problems. In the new work, Antonio Convit of New York
University School of Medicine and his collaborators studied 30 people whose
average age was 69 to investigate whether sugar levels, which tend to increase
with age, affect memory in healthy people as well. The scientists administered
recall tests, brain scans and glucose tolerance tests, which measure how quickly
sugar is absorbed from the blood by the body's tissues. Subjects with the
poorest memory recollection, the team discovered, also displayed the poorest
glucose tolerance. In addition, their brain scans showed more hippocampus
shrinkage than those of subjects better able to absorb blood sugar.
"Our study suggests that this impairment may contribute to the memory
deficits that occur as people age," Convit says. "And it raises the intriguing
possibility that improving glucose tolerance could reverse some age-associated
problems in cognition." Exercise and weight control can help keep glucose levels
in check, so there may be one more reason to go to the gym.
单选题
Which of the following statements is nearest in meaning to the sentence
"To sleep. Perchance to file?"?
A. Does brain remember files after one falls asleep?
B. Does brain arrange memories in useful order during sleep?
C. Does brain have memories when one is sleeping?
D. Does brain work on files in sleep?
【正确答案】
B
【答案解析】[解析] 根据第一段第二句“Findings...further support the theory...”可知，科学发现进一步支持了以下理论，即当人睡眠时，大脑会对白天形成的记忆进行组织和储存。所以本题选B。
单选题
What is the result of the experiment with rats and mice carried out at
Rutgers University?
A. Somatosensory neocortex and hippocampus work together in memory
consolidation.
B. Somatosensory neocortex plays its primary role in memory
consolidation.
C. The electrical activity is emanating from the somatosensory
neocortex.
D. Oscillations in brain waves are from hippocampus.
【正确答案】
A
【答案解析】[解析] 由文章第二段第二句“they examined...the somatosensory neocortex...and the hippocampus”可知，科学家分析了源自大鼠和小鼠的躯体感觉新皮质层和海马体的脑电波。根据本段倒数第二句“The team posits that this interplay...in memory consolidation.”可知，科学家们认为两个大脑区域的互动是巩固记忆的重要步骤。由此可知A项正确，B项错误。C项和D项内容只是涉及了实验的过程，未触及到最后的结果。故本题选A。
单选题
What is the relation of memory to glucose tolerance, as is indicated by
a research mentioned in Paragraph 3?
A. People with good memory have low glucose tolerance.
B. People with poor memory have high glucose tolerance.
C. Memory level has nothing to do with glucose tolerance.
D. The poorer the memory, the poorer glucose tolerance.
【正确答案】
D
【答案解析】[解析] 根据文章第三段倒数第二句“Subjects with the poorest memory recollection...displayed the poorest glucose tolerance.”可知，科学家发现记忆力最差的实验参与者显示出最弱的葡萄糖耐受性。故本题选D。
单选题
In what way is memory related to hippocampus shrinkage?
A. The less hippocampus shrinks, the poorer one's memory.
B. There is no relation between memory and hippocampus shrinkage.
C. The more hippocampus shrinks, the better one's memory.
D. The more hippocampus shrinks, the poorer one's memory.
【正确答案】
D
【答案解析】[解析] 根据文章第三段最后一句“...their brain scans showed more hippocampus shrinkage than those of subjects better able to absorb blood sugar”可知，脑部扫描显示，与那些能更好地吸收血糖的人相比，记忆力最差的人的海马体萎缩得要更厉害。所以本题选D。
单选题
According to the last paragraph, what is the ultimate reason for going
to the gym?
A. To control glucose levels.
B. To exercise.
C. To control weight.
D. To prevent hippocampus shrinkage.
【正确答案】
A
【答案解析】[解析] 根据最后一段末句“Exercise and weight control can help keep glucose levels in check...”可知，锻炼身体和控制体重能保持葡萄糖的水平，所以本题选A。