INTERMEDIO II

READING

1   Read the article and tick (ü) A, B, or C.

For centuries, sleep was a complete mystery. In the last few years, however, scientists have been able to use new technology to investigate electrical and muscular states of the body during sleep. These investigations have shed new light on the six recurring stages of sleep, which were first described in the early 20th century. It is fair to say that we now have a much better understanding of what actually happens to us when we are sleeping, though it is far from a totally clear picture.

The first stage of sleeping is called, somewhat confusingly, ‘waking’. By this, sleep scientists mean a short period of wakefulness, just a matter of minutes, when the body is relaxed and prepares for sleep. Tense muscles relax, eye movement slows down, and the body slips gently towards drowsiness.

Once feeling drowsy, the sleeper has moved into a period known to the scientists as ‘stage 1 sleep’, a period which lasts no more than ten minutes. A way of describing this stage is to say that the sleeper is on the very edge of sleep, with their eyes closed and their bodies still. However, it wouldn’t be difficult to rouse a person at this stage. And once awake, a person may feel as if he or she has not slept.

By stage 2, the sleeper has entered a period of light sleep, perhaps best explained as a time when the muscles of the body hover between being completely relaxed and being responsive. Then, as the heart rate quickly slows down, and the body temperature drops, the body prepares to enter a much deeper phase of sleep. The third and fourth stage of sleep are when the body is completely asleep, its muscles paralysed, its breathing regular.

What happens next is quite unexpected. From the deep sleep of stage 4, the body works backwards through stage 3 sleep to the light sleep of stage 2, but then, instead of waking, it enters the bizarre and magical stage of REM sleep. The body has been asleep for about an hour and a half before reaching this stage.

REM stands for ‘rapid eye movement’. The heart rate speeds up, breathing becomes erratic, and the brain becomes very active. The sleeper is dreaming, something that only happens during the REM stage. Fortunately, however, while the brain is in overdrive, the rest of the body’s muscles are paralysed.

The initial REM stage is over after ten minutes or so. Then, the body starts its sleep cycle all over again, with the next REM stage taking a bit longer. In a typical night’s sleep, there will be five different sleep cycles with the final REM stage lasting as long as an hour.

Naturally, there are many factors which influence our sleep cycle, not least age. Small children get more deep sleep than anybody else, and, as a general rule, the older we get the shorter the time we spend in deep sleep. But, while stage 3 and stage 4 of the sleep cycle shorten with age, the first REM stage lengthens.

So, there you have it. Next time you go to bed and lay your head on the pillow, just imagine what adventures your sleeping self is about to set off on.

Example: For hundreds of years, people had no idea what happened when we slept.

A  True   ü     B  False          C  Doesn’t say      

1   In recent years, scientists have used technological advances to better understand what takes place when we sleep.

     A  True          B  False          C  Doesn’t say     

2   During the ‘waking’ period a person is fast asleep.

     A  True          B  False          C  Doesn’t say      

3   ‘Waking’ is different from ‘stage 1 sleep’ because it lasts much longer.

     A  True          B  False          C  Doesn’t say      

4   If you wake up a sleeper during ‘stage 1 sleep’, he / she won’t be able to get back to sleep.

     A  True          B  False          C  Doesn’t say     

5   Features of ‘stage 2 sleep’ include decreasing body temperature and heart rate.

     A  True          B  False          C  Doesn’t say     

6   A typical sleep cycle happens in this order: waking ® stage 1 ® stage 2 ® stage 3 ® stage 4 ® REM stage

     A  True          B  False          C  Doesn’t say   

   

7   In a typical sleep cycle, a person is asleep for approximately 90 minutes before starting to dream.

     A  True          B  False          C  Doesn’t say   

   

8   A faster heart beat is a feature of REM sleep.

     A  True          B  False          C  Doesn’t say    

  

9   As a typical sleeper moves from one sleep cycle to the next, he / she is likely to spend more time dreaming with each sleep cycle.

     A  True          B  False          C  Doesn’t say   

   

10   Older people generally enter REM sleep quicker and stay there longer.

     A  True          B  False          C  Doesn’t say      

2   Match five of the highlighted words / phrases to the definitions.

Example:    a bit sleepy   drowsy

1   happening over and over again

2   unable to move

3   be in a state that may change at any time

4   the effect of something or somebody

5   irregular

6  added more information
7  first
8   wake up
9   to start being very active
10   several things that cause or influence something

source: NEF I2

answers:
1. ABBCABAAAA
2. recurring, parlysed, hover, influence, erratic, shed new light, initial, rouse, overdrive, factors