Final Test Audio Script
Wilson: Alright, Abolaji, you’re next. Are you ready?
Wilson: OK then, start when you like.
Abolaji: Good morning everybody. Let me start with a question. Do you like sleeping?
Students: Yes! No!
Abolaji: Today I’m going to talk to you about sleep. I hope to show you that sleep is a very important and interesting subject. But please stay awake – don’t fall asleep during my presentation!
Scientists are starting to understand sleep much better than before, and I’ll mention some new research in my talk. Because of the limited time, I’ll cover three areas:
1 how much sleep we need
2 the types and stages of sleep, and
3 some problems with sleep in today’s society.
So, let’s look first at how much sleep people need. Most people spend around a third of their lives asleep, although the need for sleep decreases with age. A one-year-old baby needs about fourteen hours of sleep a day, a child of five needs about twelve hours, and an adult about seven to eight hours. However, different people need different amounts of sleep. Some adults need to sleep for ten hours or more a day, while others only need half that amount or less. Elderly people tend to sleep less than younger adults at night, but they doze more during the day.
Let’s turn now to the different types of sleep, and I apologise for using some rather technical language here. There are two types of sleep, known as REM sleep and NREM sleep. REM means rapid eye movement. NREM means non-rapid eye movement. Most of our sleep – about 80 per cent of the sleeping pattern – is NREM sleep; during this time, brain activity falls to its lowest level. In REM sleep, the brain suddenly becomes more active – like the brain of a person who’s awake. The eyes move rapidly and dreams occur. REM sleep is about one half of sleep time in babies, and about one fifth of sleep time in adults.
Abolaji: OK. Turning to the stages of sleep, we can identify five stages in a night’s sleep, as you can see on the slide. In different stages of sleep, our brains put together thoughts and experiences, then store them in an organised way, giving us clearer memories. According to Robert Stickgold, a sleep researcher at Harvard Medical School in Boston, it seems that different kinds of sleep improve different kinds of memories, and this might be why we have the five different stages of sleep. Recent experiments suggest that the final stage of sleep, REM sleep, is very important for organising our memories and helps to improve our learning. NREM sleep is important for making our memories stronger. Experiments have also shown that the brain works in a different way after we’ve had a good night’s sleep.
The final area I want to talk about are things that can stop us sleeping well. One of them is too much light. Street lights and security lights mean that even when we’re asleep, it’s never completely dark. And the evidence suggests that the quantity and quality of darkness in our lives affects our health. Another problem is the 24/7 world, with the Internet, 24-hour shopping, global travel, etc. Because of this, our days are becoming longer and the nights shorter – and this could also damage our health, as we’re not getting enough sleep.
To sum up, I hope I’ve succeeded in showing you that sleep is a very important and interesting subject. We sleep less as we get older, but everybody’s different – some people need more sleep, others less. There are two types of sleep – NREM and REM; most sleep is NREM, but REM is when dreaming happens. During the five different stages of sleep, our brains organise our memories and make them stronger. But too much light and our modern way of life can have a negative impact on our sleeping patterns and, as a result, on our brains and our health. Thank you for listening. Are there any questions? Is anyone still awake?
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