CHAPTER 6: States of Consciousness
How do the brain and environment regulate circadian rhythms?
Circadian rhythms regulated by (SCN)
SCN neurons link to pineal gland, which secretes melatonin
Neurons in SCN are active during daytime
– Inhibits melatonin secretion
– Raises body temperature and alertness
Neurons in SCN become inactive at night
– Allows melatonin secretion to increase
– Melatonin promotes relaxation and sleepiness
2. What brain-wave patterns distinguish the first four stages of sleep?
Stage 1 is theta waves, the person is in a light sleep and may experience ‘body jerks’
stage 2 sleep is deepen, the muscles relax and the brain go through rapid burst of activity for 1-2 seconds (sleep
stage3 sleep deepens further, regular appearance of delta waves
stage 4 sleep deepens, delta waves dominate pattern. Stage 4& 3 together is slow-wave sleep
3. Describe some major characteristics of REM sleep.
-Rapid Eye Movement
-Brain wave activity increases
-REM sleep paralysis, voluntary muscles difficult to contract
4. Explain the restoration and evolutionary theories of sleep, and briefly describe an
experiment that you would do to test the restoration theory of sleep.
Sleep recharges the body and each species evolved a sleep-wake pattern that increased its chance of survival in
relation to environmental demands. An experiment that could be done to test the restoration of sleep theory is to
leave the body to free-run. That is to take away all clocks and predetermined schedules to see how the body
responds to regular stress and how it copes.
5. Some researchers think that REM serves a special function. What is that special
function, and what evidence supports or contradicts this hypothesis?
Researchers think REM serves a cognitive-processing function. That is to say, when we dream (enter REM) our
brain synthesizes problems and tries to solve it or makes sense of it. There have been studies where test subjects
took a test and then took it again later without a nap between the two tests. They did the same test again,
however this time they underwent REM and then did the test. The test group that took the test after they had a
nap scored higher than the group that just took the break.
6. According to Freudian psychoanalytic theory, activation-synthesis theory,
dream models, and cognitive-process dream theory, why do we dream?
Freudian psychoanalytic theory: representation of latent desires we have yet to realize.
Activation-synthesis theory: when we dream, random parts of the brain are activated, dreams are our brain
synthesizing it and making sense of it all.
Problem solving dream models: helps us find solutions to personal problems and concerns
Cognitive-process dream theory: dreams and waking thoughts uses the same processes in the brain.
7. How do agonists and antagonists alter synaptic transmission? Provide an example of
each, and describe how it works.
Agonists work by increasing neurotransmitter activity, the drug binds to the protein receptor and causes it to
respond to how it would with a natural occurring substance. Examples of agonists are nicotine, and morphine.
Antagonists work in the opposite way. The drug binds to the receptor site and inhibits activity some examples of
antagonists are: marijuana and tranquilizers. 8. What is the relation among tolerance, compensatory responses, and withdrawal?
As a person takes a drug for a period of time, the body will try to maintain homestatsis so they will feel the effects
of the drug less. The person at that point will then increase their dosage to feel the results of the drug.The body
will then in effect, produce physiological reactions opposite to the drug (compensatory response) as the body is
compensating for the imbalances. After the drug has been discontinued the body will then continue compensatory
responses to get the body back to regular.
9. Explain how alcohol affects the brain.