Learning Module 4: Evaluate
Title: Are you dreaming? The adaptation of sleep
Objectives:
- Evaluate the spectrum of behavior
- Extend understanding of the qualifications of behavior through the notion of sleep
- Evaluate the adaptive nature of sleep
- Recognize the (human) need for sleep and the harmful effects of not enough sleep
- Evaluate how sleep or rest is connected to being alive
- Acknowledge the complexity of questions in science by considering whether or not all living things sleep
- Evaluate the uniqueness of human behavior by presenting research that humans are not the only species to sleep and even dream
- Evaluate the ways science is used, or misused, to make money
Materials and Preparation:
Check out for some free resources including a crossword puzzle, quiz, and short movie on sleep. (These may or may not be the appropriate level for specific classes.)
Students should record their dreams or a family member’s dreams and answer the questions provided before this class:
Dream Journal
Have students record their dreams and try to make connections between events during the day and their dreams at night. It is important to write down dreams as soon as you wake up because chances are you will forget them later in the day. Questions include things like what did you do right before bed, what was the biggest event of the day, did anything happen out of the ordinary…
This is an at home experiment students may enjoy, but it is not included in the lesson as written:
Human Alarm Clock
(This is best to do on the weekend or when you don’t have to be somewhere at a certain time). When you get in bed, tell yourself you want to wake up at a specific time such as 8:00am. The next morning record what time it is when you wake up. Repeat this as many nights as you can to see if you wake up closer and closer to the exact time, in this case 8:00am. This is a great example of circadian rhythms that control our functioning.
Background Information:
Terms:
voluntary behavior – a behavior that occurs with conscious control
involuntary behavior – a behavior that occurs without conscious control
sleep – a typically recurring condition in which the body and mind rest by relaxing muscles and suspending consciousness
REM sleep – a type of sleep repeating in intervals throughout a period of sleep characterized by rapid eye movements (REM), higher dream frequency, increased heart rate and breathing
dream – thoughts, images, or sensations that take place while a person is sleeping
pseudoscience – a set of practices or beliefs that the general public mistakenly assumes to be grounded in the scientific method
Resources:
How Stuff Works
Dream Theories
How Stuff Works
Dream Experiments
How Stuff Works
How Sleep Works
Biological Rhythms Experiments
The Human Alarm Clock
Why Do I Need Sleep?
Sleep Video, Crossword Puzzle, and Quiz
Activities:
Attention Getter
The phenomenon of sleep and dreams has caused humans to marvel for much of our history. Why is it that we sleep? Do some people need more sleep than others? What are our dreams trying to tell us? Is sleep different for different species? These questions and many others have created a lucrative market for scientists—and pseudo-scientists—to profit. Specifically, dreaming in humans has sparked many theories as to the purpose and even the meaning of dreams.
Think & Write: What do you think? Why do humans dream?
Several Sides
Present the following opposing theories regarding why we dream. (The following information is taken directly from Howstuffworks.com.):
“For centuries, we've tried to figure out just why our brains play these nightly shows for us. Early civilizations thought dream worlds were real, physical worlds that they could enter only from their dream state. Researchers continue to toss around many theories about dreaming. Those theories essentially fall into two categories:
1. “The idea that dreams are only physiological stimulations”
“Physiological theories are based on the idea that we dream in order to exercise various neural connections that some researchers believe affect certain types of learning.”
Prominent Physiological Theory:
“More recently, around 1973, researchers Allan Hobson and Robert McCarley set forth another theory that threw out the old psychoanalytical ideas. Their research on what was going in the brain during sleep gave them the idea that dreams were simply the result of random electrical brain impulses that pulled imagery from traces of experience stored in the memory. They hypothesize that these images don't form the stories that we remember as our dreams. Instead, our waking minds, in trying to make sense of the imagery, create the stories without our even realizing it -- simply because the brain wants to make sense of what it has experienced. While this theory, known as the activation-synthesis hypothesis, created a big rift in the dream research arena because of its leap away from the accepted theories, it has withstood the test of time and is still one of the more prominent dream theories.”
2. “The idea that dreams are psychologically necessary”
“Psychological theories are based on the idea that dreaming allows us to sort through problems, events of the day or things that are requiring a lot of our attention. Some of these theorists think dreams might be prophetic.”
Prominent Psychological Theories:
“First and foremost in dream theory is Sigmund Freud. Falling into the psychological camp, Dr. Freud's theories are based on the idea of repressed longing -- the desires that we aren't able to express in a social setting. Dreams allow the unconscious mind to act out those unacceptable thoughts and desires.”
“Carl Jung studied under Freud but soon decided his own ideas differed from Freud's to the extent that he needed to go in his own direction. He agreed with the psychological origin of dreams, but rather than saying that dreams originated from our primal needs and repressed wishes, he felt that dreams allowed us to reflect on our waking selves and solve our problems or think through issues.”
3. “Many researchers and scientists also believe that perhaps it is a combination of the two theories.”
Testing Theories
Before you move on to the following activity, you may want to share these dream facts with your students (also directly taken from Howstuffworks.com).
- “Most dreams last anywhere from five to 20 minutes.
- People don't only dream in black and white, as was once believed.
- Even though they may not remember them, everyone dreams several times a night. In fact, during a typical lifetime, we spend about six years dreaming.
- People who have been blind from birth have dreams that are formed from their other senses (e.g., touch, smell, sound).
- When people are snoring, they're not dreaming.
- Elephants (and some other animals) sleep standing up during non-REM sleep, but lie down for REM sleep.”
Activity:
Dream Journal
Have students discuss, in groups, the content of their dream journals. Students should specifically address the events, images, or situations presented in dreams in relation to the events or situations of the day preceding the given dream. Once groups begin to recognize patterns (or not), have them decide which theory seems best supported by their journal findings. Groups should be prepared to share their final decision with the entire class.
Think & Write: What experiment could you do to better prove one dream theory over another? Specify the theory you would support and how.
Review the following information regarding sleep with your students (this information is taken directly from the “Why do I need sleep?” page at :
Effects of not enough sleep
“Skipping one night's sleep makes a person cranky and clumsy. After missing two nights of sleep, a person will have problems thinking and doing things; his or her brain and body can't do their normal tasks nearly as well. After five nights without sleep, a person will hallucinate (this means seeing things that aren't actually there). Eventually, it becomes impossible for the brain to give its directions to the rest of the body without sleep - the brain needs to spend time in bed and catch its ZZZs!”
Sleep requirements of humans at certain ages and of different animals
Adults can get by on about 7 hours of sleep per day
Human kids need 10 or 11 hours, but most only get 9 ½ hours
Babies sleep 14-15 hours per day, including naps
Lions get as much as 20 hours of sleep per day
Chimpanzees sleep 12 hours per day
Pigs need about 8 hours of sleep per day
Koala bears sleep 18-20 hours per day
Cats sleep for 16 hours a day
Mice sleep 12 hours
Elephants only need 4-6 hours
A sloth will sleep 20 hours in a day
Giraffes only get 30 minutes of sleep a day (broken into 6 five-minute naps)
As a class, discuss how these facts regarding sleep in addition to the dream theories illustrate that sleep is both voluntary and involuntary.
Think & Write: Based on what you have learned so far, do you think sleep and specifically dreaming are adaptive? Why or why not?
Reflect
Think & Write: Is human sleep unique? If so, how? How could an experiment test your hypothesis about human sleep’s uniqueness?