Sleep scientists are still in disagreement about how many hours of sleep the average person needs to remain healthy. Some claim eight hours while others claim we can do fine with six hours. Moreover, many scientists are asking what exactly is the purpose of sleep?
ESL Voices Lesson Plan for this post with Answer Key.
Excerpt: How much do we really know about sleep? By Tom Chivers,The Telegraph-Science
“We spend a third of our lives doing it, and yet we still don’t fully understand the reasons why we sleep. Tom Chivers meets the scientists devoting their lives to plumbing its mysteries – and learns the perils of ignoring its importance
How much do we really know about sleep? There is no single activity that humans do more: if you live to be 90, you will probably spend 32 years asleep. It is as vital for us as eating or drinking water. Sleep deprivation will kill you as surely as starvation. It is an activity we share with every other animal species, from cockroaches to chimpanzees. Yet we do not fully understand why we do it. Sleep scientists are locked in furious disagreements about what it’s for. Some suggest it’s to do with memory; some suggest it’s about clearing toxins from the brain; others suggest a combination of several factors. Others are even trying to establish whether humans can do without it altogether, using pharmaceutical drugs.
The question of why we sleep is incredibly interesting, says Prof Russell Foster, a neuroscientist and sleep specialist at the University of Oxford. You have to disentangle it into two parts. One, what’s going on in the human brain as we sleep, and two, why did sleep evolve? They’re related, but they’re not the same. From an evolutionary point of view, on the surface, sleep is baffling. But perhaps it’s not as mysterious as we think, and perhaps it does not have just one vital function, but many.
The Earth has been spinning around the Sun for five billion years. Life, in some form or another, has been clinging to its surface for at least 3.5 billion of those. Early on in the cycle, animals, and indeed plants, became adapted to the varying pressures of the light-dark cycle, says Foster. They developed what we now know as a biological clock: a fine-tuning of physiology and behaviour to deal appropriately with that cycle.
For humans, there are four distinct phases of sleep: three largely dreamless phases of increasing depth, then a highly active period, known as “rapid eye movement” or REM sleep, when most of our dreams happen. Dreaming has a real biological function, says Williams.
Foster believes the brain is making sense of events, that it is putting together a “jigsaw” of information and that the pieces that it can’t fit into its usual model of how the world works create the bizarre associations of dreams.
Also controversial is the phenomenon of “lucid dreaming”: wakefulness in dreaming, when dreamers are aware of the dream and able to control their actions. says Foster, it is a real phenomenon, and what’s more, some people can train themselves to do it, much like the sci-fi film Inception.
What’s strange about all this is how sleep, a third of our lives, takes up so little of our thinking. Medical schools dedicate almost no teaching to it; our education system worries about so much else, but not about the very simple and obvious fact that sleep deprivation ruins children’s ability to learn.”
Level: Intermediate -Advanced
Language Skills: Reading, writing, speaking and listening. Vocabulary and grammar activities are included.
Time: Approximately 2 hours.
Materials: Student handouts (from this lesson) access to news article, and video.
Objective: Students will read and discuss the article with a focus on improving reading comprehension and learning new vocabulary. At the end of the lesson students will express their personal views on the topic through group work and writing.
I. Pre-Reading Activities
Stimulating background knowledge
Directions: Place students in groups, ask students to think about what they already know about the topic. Next, have students look at the picture(s) in the text and generate ideas or words that may be connected to the article. Debrief as a class and list these ideas on the board.
Students can use the UIE brainstorming chart (sample) for brainstorming the meanings.
II. While Reading Activities
Directions: Students are to infer the meanings of the words in bold taken from the article. They may use a dictionary, thesaurus, and Word Chart by Education Oasis for assistance.
- It is as vital for us as eating or drinking water.
- Sleep deprivation will kill you as surely as starvation.
- Why did sleep evolve?
- If you’re a nocturnal animal, you’ve got big ears and eyes.
- We tend to think of sleep as just an absence of consciousness.
- The first four hours or so you spend more time in restorative non-REM sleep.
- Also controversial is the phenomenon of lucid dreaming.
- Sleeping is essential for survival.
- In future, it may be possible to use drugs to reduce our sleep need, or even mimic it.
- People are self-medicating with stimulants and sedatives.
Directions: Review the following statements from the reading. If a statement is true they mark it T. If the statement is not applicable, they mark it NA. If the statement is false they mark it F and provide the correct answer.
- According to the article we spend half of our lives sleeping.
- Sleep scientists are in disagreement about why we sleep.
- Some members of the animal kingdom are forced to spend perhaps a third of their lives unconscious and vulnerable.
- Some scientists think there may be more than one function for sleep.
- For humans, there are nine distinct phases of sleep.
- Rapid eye movement or REM sleep, is when we can’t sleep.
- Animals in the wild require more sleep than humans.
- According to Adrian Williams Dreaming has a real biological function.
- Rechtschaffen was a sleep scientist who experimented with fruit flies.
- Paul McCartney claims that he woke up one morning with the tune for Yesterday already playing in his head.
Directions: The following sentences from the article are scrambled. Have students unscramble each sentence. Students can find the original sentences in the reading to check their work.
- How really sleep about know we much do?
- deprivation starvation will kill you Sleep surely as as.
- interesting incredibly I is sleep we why of question The.
- very brain active REM sleep The is during.
- For humans, phases there distinct sleep are four of.
III. Post Reading Tasks
Reading Comprehension Check
Directions: Have students use the WH-question format to discuss or to write the main points from the article.
Who or What is the article about?
Where does the action/event take place?
When does the action/event take place?
Why did the action/event occur?
How did the action/event occur?
Directions: Place students in groups and have them answer the following questions. Afterwards, have the groups share their thoughts as a class. To reinforce the ideas, students can write an essay on one of the following discussion topics. Review Review ESL Voices Modes of Writing
- The article states, “ Whatever is going on when we sleep, we do know one thing: we’re not doing it enough, and we’re doing it badly. We’re dosing ourselves with caffeine and nicotine to stay awake, and knocking ourselves out with alcohol and sleeping tablets, and all the while stopping ourselves from getting the healthy, normal sleep that lets our brains function.” How would you put this idea into your own words? Provide examples.
- According to the article, “A study in America found that teenagers need an average of nine hours’ sleep, but that a quarter were getting less than six-and-a-half.” What reasons could you give for this problem with teens?
- Do you think that you get enough sleep? Provide reasons for why or why not.
IV. Listening Activity
Video Clip: Sleep Deprivation Can Have Devastating Consequences.
Doctors examine the reasons for sleep deprivation in people who work at night.
While Listening Activities
Directions: Review the statements with students before the watching the video. As students listen to the video if a statement is true they mark it T. If the statement is not applicable, they mark it NA. If the statement is false they mark it F and provide the correct answer.
- 16 % of Americans work the night shift.
- Sleep derivation is a major problem on the night shift.
- Air traffic controllers fall asleep on the night shift.
- Sleep depravation can affect our health and our safety.
- People with sleep deprivation are as dangerous as people intoxicated with alcohol.
- Sleep deprivation can cause gastric ulcers.
- Air traffic controllers fall asleep more than other night workers.
- The concept of napping is not necessarily the answer because people can remain groggy after a nap.
- One solution is to wear dark glasses when driving home from a night shift.
- Another solution is to rotate the shifts so that people who work the night shifts can get regular sleep.
Questions for Discussion
Directions: Place students in groups and have them discuss the following questions.
1. After listening to this video has your personal idea of sleep deprivation changed in any way? If yes, describe in what way. If no, describe your original opinion.
2. Make a list of other jobs where people work nights. Research to find out how much trouble workers have with staying awake on these jobs. Make a list of possible solutions and share them with the class.
3. With your group members, make up questions that you would like to ask the doctors, or people who work night shifts.
ANSWER KEY: What is Sleep?