Question

Why can some people sleep through noises like a  honking car or flushing toilet, while others are awakened by the lightest  sound?

To find the answer, sleep researchers at Massachusetts  General Hospital conducted an unusual study of 12 self-described deep sleepers.  After tests confirmed that the healthy volunteers were solid sleepers, they  took part in a three-night study in the university’s sleep laboratory. The  participants spent the night in a big and comfortable room. But the room also  included four speakers positioned near the top of the bed.

During the night, the deep sleepers were  subjected to 14 different recorded sounds, like street traffic, toilets  flushing, and an airplane flying overhead. Next door, the researchers monitored  their sleep patterns and brain waves.

As expected, all of the participants slept  relatively well, but there were differences in how they responded to the noisy  interruptions. Some of the sleepers didn’t wake up even when a sound was  blasted at 70 decibels（分贝）；others were awakened by sounds at 40 or 50  decibels.

The researchers discovered that the difference  in a sleeper’s reaction to noise could be predicted by the level of brain  activity called “sleep spindles（纺锤体）”. A sleep spindle is a burst of high-frequency  brain activity coming from deep inside the brain during sleep. The source of  the spindles is the thalamus（丘脑）, a part of the brain that sends sensory  information to the rest of the cortex（皮层）.

Before the study, the Massachusetts researchers  theorized that the spindles are the brain’s way of preventing sensory  information from passing through the thalamus and waking the rest of the brain  during sleep. They found that sleepers who experienced the most sleep spindles  during the night were also the soundest sleepers and were least likely to be  awakened by noise.

Scientists already know that most people become  lighter sleepers with age, most likely because older people experience less  “slow wave sleep”, which is the deepest stage of sleep. People also produce  fewer sleep spindles as they age. But even when controlling for the stage of  sleep a person was in, the number of sleep spindles still predicted their risk  for awakening because of noise.

More research is needed, but the findings  suggest that a better understanding of sleep spindles could lead to new behavioral  or drug therapies for people with sleep disorders. For example, future studies  may try to determine whether diet, exercise or other behaviors may influence  the number of sleep spindles a person produces during the night.

71. Some participants can sleep well  through loud noises mainly because ________.

A. their brains don’t respond to outside noises.

B. their brains react differently to noises.

C. they adapt too the environment quickly. 

D. they don’t pay attention to the monitors.

72.  Scientists believe that the key to affecting deep sleep is__________.

A. sleep spindles                           B. stages of sleep         

C. sleep disorders                           D.  sensory information

73.  It can be learned from the passage that_____________.

A. The older a deep sleeper becomes, the lighter  his sleep must be.

B. The more “slow wave sleep” one experiences,  the deeper sleep one has.

C. The more frequently a sleeper’s brain works,  the less information it sends.

D. The deeper sleep people have, the more likely  they will be awakened by noise.

74.  From the passage we can predict____________.

A. more factors in influencing sleep spindles  may be discovered.

B. more solid sleepers will take part in  relative experiments.

C. sleep spindles will be applied to change  one’s behaviors.

D. deep sleepers will probably enjoy a more  healthy life.

75.  What is the main idea of the passage?

A. The differences between the deep sleepers and  the light sleepers.

B. The experiments conducted by Massachusetts  General Hospital.

C. The discovery and the importance of “sleep spindles”.

D. The new behaviors or drug therapies for  people with sleep disorders.

Answer 1

【全文翻译】

为什么有些人睡到像一辆车的噪音或冲洗厕所，而其他人却被最轻的声音惊醒？

为了找到答案，麻省总医院的睡眠研究人员对12名自称深睡眠者进行了一项不同寻常的研究。经过测试证实健康志愿者是真正的睡眠者，他们参加了大学睡眠实验室的三晚的研究。参加者在一个舒适的大房间里过夜。但是房间里也有四个扬声器靠近床的顶部。

在夜间，深睡者受到14种不同的声音，比如街道交通，厕所冲水，还有一架飞机从头顶飞过。隔壁，研究人员监测他们的睡眠模式和脑电波。

正如预期的那样，所有参与者都睡得比较好，但他们对嘈杂干扰的反应有差异。有些人没有醒来，甚至当一声爆炸在70分贝（分贝）；人被吵醒的声音在40或50分贝。

研究人员发现，睡眠者的反应的差异可由噪声水平的大脑活动被称为“睡眠纺锤波的预测（纺锤体）”。睡眠纺锤波是一种高频脑活动，来自于睡眠时大脑深处的活动。锭的来源是丘脑（丘脑），那将感觉信息的其余部分的皮层的大脑的一部分（皮层）。

在这项研究之前，马萨诸塞州研究人员推测纺锤波是大脑阻止感觉信息通过丘脑并在睡眠中唤醒大脑其余部分的一种方式。他们发现，那些经历过最睡眠纺锤波夜间睡眠也最完整的枕木，是最有可能被吓醒了。

科学家已经知道，大多数人随着年龄的增长而变得更轻，很可能是因为老年人经历了“慢波睡眠”，这是睡眠最深的阶段。随着年龄的增长，睡眠纺锤波也越来越少。但是即使控制了睡眠阶段，睡眠纺锤波的数量仍然预示着由于噪音而醒来的危险。

需要更多的研究，但研究结果表明，更好地了解睡眠纺锤波可能会导致新的行为或药物治疗睡眠障碍的人。例如，未来的研究可能会试图确定饮食、运动或其他行为是否会影响一个人夜间睡眠的数量。

71—75 BABAC