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

Sleep, Sleep Disorders, and Biological Rhythms
4. Explain that these data are sufficient to tell if an astronaut is awake
or asleep, and if asleep, whether in NREM or REM sleep. Further
explain that not all of the data may be useful for determining the
astronauts’ sleep states.
5. Give each student a copy of Master 2.6, Sleep Medicine Reference
Manual. Explain that this is a resource to help them interpret the
data they have in front of them and relate it to the astronauts’ sleep
states.
6. Instruct students to evaluate the data for each astronaut, using the
information in the Sleep Medicine Reference Manual for comparison.
Student observations, interpretations, and conclusions should be
entered on Master 2.2, Astronaut Telemetry Evaluation Form.
7. After students have had an opportunity to complete their analyses,
ask the class, What is the state of wakefulness or sleep of each of
the three astronauts?
Astronaut Jordan is in REM-stage sleep. Astronaut Rodriguez is in
NREM-stage sleep. Astronaut Chen is awake.
8. Ask the class, Which physiological data are useful for determining
a person’s state of wakefulness or sleep?
Content Standard A:
Students should
develop understandings
about scientific
inquiry.
Students should conclude that the important parameters for distinguishing
between sleep states and wakefulness are EEG, EMG, and
EOG. The other four parameters—heart rate, blood pressure, respiratory
rate, and body temperature—might be useful in combination
with EEG, EMG, and EOG data, but they are not sufficient by themselves.
For instance, heart rate increases during REM, but it also may
increase with physical activity during wakefulness.
9. Ask students, How can you distinguish between REM and NREM
sleep? Between REM and wakefulness? NREM and wakefulness?
The EEG, EOG, and EMG data are reproduced in Figure 2.2 (page 73).
First consider astronaut Jordan. Jordan’s EEG does not appear to
represent NREM sleep, although students may have difficulty distinguishing
between REM and wakefulness EEGs. However, the lack of
muscular activity (EMG) during REM as compared with activity
during NREM or wakefulness is the key for determining that this
individual is in REM-stage sleep. Rodriguez and Chen can be distinguished
from each other based on their EEGs (that is, the increased
amplitude and decreased frequency of brain waves during NREM
compared with the pattern during REM and wakefulness) and their
EOGs (that is, large eye movements during wakefulness as compared
with little or no eye movements during NREM).
74