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NOVA scienceNOW: Sleep
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Viewing Ideas
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Before Watching
Record information about
sleep habits. Starting the week before you view
the program, have students record four kinds of their own sleep-related
data—hours of sleep, general mood, physical energy, and mental alertness.
Ask them to record the data for a five-day period and enter it in bar graphs on
the Why Sleep Matters graphing sheet.
After five days of data collecting,
have students form groups and discuss their logs. What was the average number
of hours each person slept per night? How does this compare to what doctors
recommend (between nine and ten hours)? Was there a common pattern in relation
to daytime alertness/sleepiness? Have a recorder from each group make a list of
common findings. Then have groups share their results with the class.
As an extension, have students also
record the following information about their sleep behavior and discuss it when
they meet in groups:
The time they went to bed
and got up the next morning A general statement about
how they slept, and possible reasons for their good or poor night's sleep A log of their level of
alertness/sleepiness, in which they record every two hours during the day how
alert/sleepy they feel, using a scale of one to five (one equals least sleepy,
five equals most sleepy).
Play a
game to review sleep-related vocabulary. Have
students play the word game Choose the Correct Meaning to familiarize them with vocabulary terms related to sleep and memory. Divide
the class into three or four teams. Read a vocabulary term and the three
possible definitions aloud. Have teams take turns identifying the correct
definition for each term. -
Design a poster about sleep. Divide the class into four groups and have each
group research the questions below and present their work in a poster. (You may
choose to have groups present information in a health-brochure format.) See the
Links and Books section for sources of this information.
What are rapid eye movement
(REM) and non-rapid eye movement (NREM) sleep? What are the differences between
these two types of sleep? What is the body's
biological clock? Why is it beneficial to stay on a set sleep schedule? What
are the sleep requirements for people of different ages? What is sleep debt? What kinds of activities are affected by a lack of sleep? What are some common sleep
disorders?
(Suggested
source: http://science.education.nih.gov/supplements/
nih3/sleep/guide/info-sleep.htm)
After Watching
Make a model of the human
brain. Have student teams make a clay or
Plasticine model of the human brain. (Or, provide students with a diagram of
the brain for this activity.) The program highlights two brain regions, the
hippocampus and the neocortex, where nerve cells show coordinated activity
during sleep. As students make the brain models, have them use bright colors to
indicate the hippocampus and the neocortex. Ask teams to label the different regions
of the brain using toothpicks with labels attached.
Have students research and then
write on an index card the basic function of each region of the brain. (Include
frontal, temporal, and parietal lobes, the cerebellum, and the brain stem. The
hippocampus is in the temporal lobe. The neocortex is the top layer of the
frontal, temporal, parietal, and occipital lobes.)
(Suggested
sources: www.pbs.org/wnet/brain/3d/index.html
and http://brainmuseum.org/functions/) Play a game demonstrating how
information storage relates to memory.
Researchers have shown that long-term memories are embedded in a web of neural
connections. Individual memories aren't stored as distinct
"files," separated from all others. Rather, many connections exist
among a person's memories. To demonstrate this phenomenon, read aloud a
list of eight unrelated words, such as tub, grass, car, ring, chair,
cow, juice, and star.
Then have students write down as many words as they can remember. As a class,
list the words. The class will likely be able to recreate the list of eight
words, but individuals are less likely to get them all. Next, read, in a
mixed-up order, an eight-word list that contains four pairs of closely linked words,
such as eye, nose, boy, girl, apple,
orange, salt, pepper.
Again, have students write down as many words as they can remember. When
recalling the list, most students will write related words together because
such words are strongly connected in people's long-term memory network or
web.
Another way our brains remember
information is by grouping it in meaningful "chunks." In the above
example, students remember four pairs, or chunks, rather than eight individual
words. To retest "chunking," ask students to see how well they can
remember the next group of clustered letters: THEB IGDO GCHA SEDT HOSE ORAN
GECA TS. Then regroup the letters: THE BIG DOG CHASED THOSE ORANGE CATS and
have students explain why the second group was easier to remember. (A
sentence is like one chunk of information. All the words in the sentence are
familiar. The brain makes an image of the sentence.) Play games that test
short-term memory. The program discusses
how sleep may help the brain process short-term memories. Have students
brainstorm the definition of a short-term memory (a memory of an event that
lasts from several seconds to a few minutes). Then divide the class into groups
and have each group play the following three short-term-memory games. Conclude
with a class discussion about why seeing something multiple times might
reinforce memory. (Neural connections may be enhanced.)
What's on the Tray?
Materials for each group: tray, 25
different common items, towel
Procedure: Provide each group with
a covered tray of items. Have each group remove the cover, observe for 25
seconds, and then cover the tray again. Individual students should write down
all items they remember. Try the game a second time. Have groups share general
results. The hypothesis is that students will remember more after two trials
because their initial observation was reinforced by the second viewing. Do the
class data support this hypothesis?
What Was Taken?
Materials for each group: tray, 25
different common items, towel
Procedure: Provide each group with
a tray of items. Have students observe their tray for 25 seconds and then close
their eyes. Ask a designated member from each group to remove one item from the
group's tray. Then each person tries to identify what's missing.
Repeat the game a few times.
Again, have groups share results.
Were students better able to discover which item was missing after the second
or third trial?
Which Cities?
Material for each group: a story
that is a few paragraphs long containing the names of 5 to 10 well-known cities.
You may choose to write a story about a class trip, a sports event, or a
student discussion related to traveling.
Procedure: In each group, one
person reads the story aloud while the others listen. When the story is
finished, group members should try to list the names of the cities in the
story. Repeat and see how much difference a second reading makes.
Hypothesize some reasons why
sleep may be important for different kinds of animals. Researchers have found that even fruit flies need
sleep. Sleep is important for our survival, and for some animals, it seems be
important to learning and memory. Provide students with the information in the
first two columns of the table below. Do students see any patterns? Then have
the class hypothesize some reasons why sleep may be important for different
kinds of animals. (Be sure to let students know that only a few different
types of animals have been subjects in laboratory sleep and memory studies.
Students are only proposing hypotheses. Accept reasonable answers.)
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Animal
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Average Daily Amount of Sleep
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Sample Hypotheses
for the Role Sleep Might Play in Consolidating Memory
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Brown bat
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19.9 hours
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To process routes
they travel, finding food, and avoiding predators
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Human infant
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16.0 hours
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To process new
information from the surroundings
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Squirrel
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14.9 hours
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To process where
food is located and hidden
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Cat
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12.1 hours
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To process
strategies for capturing food and prey
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Rabbit
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11.4 hours
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To process location
of food and ways to avoid predators
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Dog
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10.6 hours
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To process social
and training experiences
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Bottle-nosed dolphin
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10.4 hours
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To process their
songs
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Chimpanzee
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9.7 hours
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To process social
interaction and locating and accessing food
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Human adolescent
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9.3 hours
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To process social
interaction and learning experiences
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Human adult
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8.0 hours
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To process social
interaction and learning experiences
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Elephant
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3.5 hours
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To process social
interaction and locating food and water
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Giraffe
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1.9 hours
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To process memories
related to location of food and water
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Data
for animal sleep times obtained from:
http://science.education.nih.gov/supplements/
nih3/sleep/guide/info-sleep.htm Learn about "daily rhythms" by performing an
activity measuring reaction time. While
the segment considers the role sleep may play in learning and memory, many
factors can affect performance. For example, most living organisms follow a circadian
rhythm, an "internal body clock"
that regulates a roughly 24-hour cycle of biological processes. Yet even with
such a biological "clock," there is variation in people's
daily rhythms, with different people experiencing such things as hunger,
maximum alertness, and tiredness at different times of the day. People often
acknowledge these differences by describing themselves as early birds or night
owls.
Explore
students' circadian rhythms by having them identify the time of day they
experience their peak performance. Have them brainstorm some of factors that
might affect performance, such as when a person last ate, one's mood, the
time of day, and events that occurred that could interfere with the ability to
focus. Ask, "How do you think time of day influences our actions and
behavior?" (Some people are more alert, feel better, and perform
better during the morning; others during the evening.) Tell students that these time-of-day changes are called circadian
rhythms, and they contribute to how we
perform and feel throughout the day.
Have students rank themselves as an early bird or night
owl, based on what they think are their times of highest alertness. (Early
birds are most alert before noon and night owls are most alert during the
evening.) Discuss the Student Reaction
Time Activity below, and either copy the
procedure onto the board or onto a handout. Give each student four pieces of
grid paper, and do the first trial in class. Ask students to complete the
remaining three trials before the next class meeting.
Student Reaction Time Activity
Materials: Reaction Time Chart, 4 sheets of 1-cm grid
paper, pencil, timer (seconds and minutes)
Procedure:
On the Reaction Time Chart, mark
whether you are an early bird or a night owl. Set the timer for one minute.
Start the timer, and mark as many grid-squares as possible with a check mark.
After a minute, count the number of squares checked. Record your results in the
chart.
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Reaction Time Chart
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I think I'm more of: ___an early
bird ___a night owl
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Time of Day
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Number of checkmarks
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Early morning
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Mid morning
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Around dinnertime
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At bedtime
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Before
the next class period, make a class-data chart on the board like the one below.
Have students share their results by placing a check in the space that matches
their designation and the times of their highest and lowest scores. Once the
chart is complete, have students see if the data supports the idea that
performance is influenced by time of day. Emphasize that one's circadian
rhythm impacts alertness and, therefore,
learning, memory, and performance. Have students brainstorm how a
person's circadian rhythm could
play a role in activity choices (e.g., playing games late at night or playing
sports early in the morning); work or career choices (e.g., being an
emergency-room surgeon or an air-traffic controller); and personal choices
(e.g., whether one gets sufficient sleep). Also ask about what people can do to
make adjustments when their school or work schedules conflict with their
natural rhythm (e.g., take naps). End
the discussion by brainstorming variables that may have influenced the activity
results. (Students may have experienced different stressors, amounts of sleep,
or levels of nutrition.) Have students
suggest controls that would make the investigation more reliable. (Some
students may suggest keeping participants in a more uniform environment that
would better control sleep, stress, and diet.)
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Time of Day
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Early-Birds
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Night-Owls
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Place an "X" when you got
your highest score
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Place an "X" when you got
your lowest score
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Place an "X" when you got
your highest score
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Place an "X" when you got
your lowest score
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Early morning
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Mid morning
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Around dinnertime
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At bedtime
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Web Sites
NOVA scienceNOW
www.pbs.org/nova/sciencenow/3410/01.html
Offers sleep-related resources,
including additional activities, streamed video, and reports by experts.
Are You a Lark, an Owl, or a
Hummingbird
nasw.org/users/llamberg/larkowl.htm
Presents an excerpt from a book
about daily rhythms and the body clock.
Clockwork Genes
www.hhmi.org/biointeractive/clocks/index.html
Contains four animations on
biological clocks, pertinent articles, and an online biological clockworks
exhibit.
Information about Sleep
science.education.nih.gov/supplements/nih3/sleep/guide/info-sleep.htm
Includes information about the
sleep cycle, sleep requirements, the function of sleep, and sleep disorders.
Neuroscience for Kids
faculty.washington.edu/chudler/chmemory.html
Provides a variety of
memory-related experiments.
Power Nap Prevents Burnout;
Morning Sleep Perfects a Skill
nimh.nih.gov/Press/sleep.cfm
Summarizes "power
nap" and sleep studies that suggest sleep enhances some types of learning.
Researchers Find the Snooze
Button
www.hhmi.org/news/sehgal20060608.html
Describes research using fruit
flies which considers the role of "mushroom bodies" on regulating
sleep.
Sleep Forms Memory for Finger
Skills
www.pnas.org/cgi/doi/10.1073/pnas.182178199
Describes results of a
finger-to-thumb motor skill task. Findings indicate that sleep is important for
consolidation of motor skill memories.
Books
The Body Clock Guide
to Better Health
by Michael Smolensky and
Lynne Llamberg. Henry Holt and Co., 2000.
Discusses the importance of body rhythms in relation to
health.
The Promise of Sleep
by William C. Dement and
Christopher Vaughan. Dell, 2000.
Describes sleep disorders and discusses the importance of
sleep.
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