Biological - NIH Office of Science Education - National Institutes of ...

Sleep, Sleep Disorders, and Biological Rhythms
d. average total sleep time
e. average number of caffeine-containing drinks in morning,
afternoon, and evening
f. number of students who snore
g. number of students who report sleeping difficulties
2. Instruct students to calculate the class average for each of the items
a through e in Step 1 (pages 59-60).
Content Standard A:
Design and conduct
scientific investigations.
Content Standard A:
Communicate and
defend a scientific
argument.
Content Standard A:
Students should
develop abilities to
formulate and revise
scientific explanations
and models using
logic and evidence.
Please ensure that a copy of the class data is retained for later reference.
Ask students to a) compare their own data with the class data
(for example, How does their average total sleep time compare with
the average total sleep time of the class?); b) compare the data
entered by males with that entered by females; and c) determine
whether there is a correlation between evening consumption of caffeine
and average bedtime or average total sleep time.
3. Ask the class to generate a hypothesis about sleep that can be
answered using the class data.
There are a number of possibilities. For example, students might
hypothesize that individuals who snore sleep less per night than
individuals who do not snore. Another possibility is that students
might observe that their calculated average sleep time is quite unlike
either their usual weekday sleep times or their usual weekend sleep
times. Perhaps students are sleeping far less on weekdays than on
weekends. Such analysis leads to discussion of sleep debt and good
sleep habits, which will be addressed in Lessons 4 and 5. There is
also the option of compiling data separately for males, females, and
the class as a whole.
4. To conclude the activity, explain to the class that we feel pressure to
sleep in daily cycles. Scientists refer to this need-to-sleep cycle as
“homeostatic regulation.” Ask students to draw a graph that depicts
the need to sleep (on the y-axis) versus the time of day (on the x-axis).
Students should conclude that the need to sleep increases throughout
the day, reaching some level that is sufficient (in combination
with other factors) to induce sleep. Sleep itself causes a decline in
the need to sleep. This is depicted in Figure 1.2.
Students may draw the line more-or-less linear. The important point,
however, is that homeostatic regulation of sleep is cyclic, rising during
wakefulness and then declining during sleep.
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