Look at the ten statements for this part. You will hear a passageabout "A Research on Sleep ". You will listen to it twice.

Look at the ten statements for this part.
    You will hear a passage about "A Research on Sleep ". You will listen to it twice.
    Decide whether you think each statement is right(R), wrong(W)or not mentioned(NM).
    Mark your answers on the Answer Sheet.
                            A Research on Sleep
    When you first drift off into slumber, your eyes will roll about a bit, your temperature will drop slightly, your muscles will relax, and your breathing will slow and become quite regular. Your brain waves slow down a bit too, with the alpha rhythm predominating for the first few minutes. This is called Stage 1 sleep.
    For the next half hour or so, as you relax more and more, you will drift down through Stage 2 and Stage 3 sleep. The lower your stage of sleep, the slower your brain waves will be. Then, about 40—60 minutes after you lose consciousness, you will have reached the deepest sleep of all. Your brain waves will show the delta rhythm. This is Stage 4 sleep.
    You may think that you stay at this deep fourth stage all the rest of the night, but that turns out not to be the case. Instead, about 80 minutes after you fall into slumber, your activity cycle placed by the activity pattern of brain waves increases. Your eyes will begin to dart around under your closed eyelids as if you were looking at something occurring in front of you. This period of Rapid Eye Movements lasts for some 8-15 minutes and is called REM sleep. During both light and deep sleep, the muscles in your body are relaxed but capable of movement. However, as you slip into REM sleep, a very odd thing occurs — most of the voluntary muscles in your body become paralyzed. Although your brain shows very rapid bursts of neural activity during REM sleep, your body is incapable of moving. In more technical terms — as we will see later in this chapter — we can say that REM sleep is accompanied by extensive muscular inhibition.
That is the end of Part 3. You now have 20 seconds to copy your answers on the Answer Sheet.