8.Wakefulness and Sleep

Question 1

What conclusion do researchers draw from the observation that workers on submarines are unable to adjust to a schedule of working 12 hours and resting 6 hours?

a. Workers on submarines probably need more sleep than most other people do.
b. People cut off from sunlight need more sleep than most other people.
c. Body temperature tends to decrease during times when people feel sleepy.
d. The human body generates a circadian rhythm.

Answer 1

d. The human body generates a circadian rhythm.

Question 2

Why do people in Antarctica during the winter often find it difficult to work together?

a. Their work schedules keep them so busy that they cannot sleep enough.
b. Their circadian rhythms drift out of phase with one another.
c. After living together in close quarters for so long, they start to irritate one another.
d. They get homesick.

Answer 2

b. Their circadian rhythms drift out of phase with one another.

Question 3

.If workers rotate between working shifts at different times of day, what would be a good way to help them adjust to the night shift?

a. Use dim lighting during the night shift.
b. Use bright lighting during the night shift.
c. Rotate from the early morning shift to the night shift, then to the late afternoon shift.

Answer 3

b. Use bright lighting during the night shift.

Question 4

What tends to be characteristic of teenagers who are extreme “evening” types?

a. They have trouble making and keeping friendships.
b. They adjust more rapidly than average to daylight saving time in the spring.
c. They get better grades in school than their abilities would predict.
d. They get worse grades in school than their abilities would predict.

Answer 4

d. They get worse grades in school than their abilities would predict.

Question 5

What evidence strongly indicates that the SCN produces the circadian rhythm itself?

a. Damage to the SCN disrupts the circadian rhythm.
b. SCN cells isolated from the body continue to produce a circadian rhythm.
c. Animals with a faster circadian rhythm have a larger SCN.
d. The SCN increases its activity during wakeful periods and decreases it during sleep.

Answer 5

b. SCN cells isolated from the body continue to produce a circadian rhythm.

Question 6

Light resets the biological clock by a branch of the optic nerve, beginning with ___ and sending the input to ___.

a. rods . . . the SCN
b. cones . . . the SCN
c. a mixture of rods and cones . . . the visual cortex
d. ganglion cells that do not require input from rods or cones . . . the SCN

Answer 6

d. ganglion cells that do not require input from rods or cones . . . the SCN

Question 7

If you want to get to sleep on time, what should you avoid?

a. Long-wavelength light late in the evening
b. Short-wavelength light late in the evening
c. Long-wavelength light early in the morning
d. Short-wavelength light early in the morning

Answer 7

b. Short-wavelength light late in the evening

Question 8

.The proteins TIM and PER reach their highest levels ___. They ___ the activity of the genes that produce them.

a. during the day . . . stimulate
b. during the day . . . inhibit
c. at night . . . stimulate
d. at night . . . inhibit

Answer 8

d.at night . . . inhibit

Question 9

Slow, large-amplitude EEG waves characterize which stage or stages of sleep?

a. Stage 1
b. REM sleep
c. Stage 2
d. Stages 3 and 4

Answer 9

d. Stages 3 and 4

Question 10

Why is REM sleep also known as paradoxical sleep?

a. Activity in the left hemisphere does not match the activity in the right hemisphere.
b. We did not know it existed until its discovery in the 1950s.
c. It is deep sleep in some ways and light in others.
d. Because a pair of docs discovered it.

Answer 10

c. It is deep sleep in some ways and light in others.

Question 11

At which time, if any, is stage 4 sleep most common?

a. Immediately after falling asleep
b. Not immediately, but during the early part of the night’s sleep
c. Near the end of the night’s sleep
d. During all parts equally

Answer 11

b. Not immediately, but during the early part of the night’s sleep

Question 12

Of the following, which two neurotransmitters increase arousal in the brain?

a. Acetylcholine and histamine
b. Acetylcholine and GABA
c. Histamine and GABA
d. Orexin and GABA

Answer 12

a. Acetylcholine and histamine

Question 13

Norepinephrine, released by the locus coeruleus, has which effect on behavior?

a. It prolongs wakefulness.
b. It increases attention to important information.
c. It produces dreams.
d. It inhibits synapses during sleep.

Answer 13

b. It increases attention to important information.

Question 14

6.How do dolphins handle breathing while they are asleep?

a. They store enough oxygen to get through the night without breathing.
b. They shift to a system of gills, like those of fish.
c. They sleep with the head out of the water.
d. Half of the brain sleeps while the other remains awake enough to surface and breathe.

Answer 14

d. Half of the brain sleeps while the other remains awake enough to surface and breathe.

Question 15

What does PGO stand for (with regard to brain function)?

a. Parasympathetic-Ganglion-Oxytocin
b. Protein-Glucose-Outcome
c. Parietal-GABA-Olfaction
d. Pons-Geniculate-Occipital

Answer 15

d. Pons-Geniculate-Occipital

Question 16

If you awaken but find you temporarily cannot move your arms or legs, what is happening?

a. You are probably developing a severe neurological disease.
b. You are probably just being lazy.
c. You need more time to get the blood flowing to your muscles.
d. Most of your brain is awake, but part of your pons and medulla remain in REM sleep.

Answer 16

d. Most of your brain is awake, but part of your pons and medulla remain in REM sleep.

Question 17

Of the following, which one is not associated with an increased probability of sleep apnea?

a. Having a relative with sleep apnea
b. Being female
c. Being overweight
d. Being middle-aged or older

Answer 17

b. Being female

Question 18

Narcolepsy is linked to a deficit of which neurotransmitter?

a. Dopamine
b. GABA
c. Orexin
d. Acetylcholine

Answer 18

c. Orexin

Question 19

When does sleepwalking usually occur?

a. During REM sleep
b. During stage 1 sleep
c. During slow-wave sleep (stages 3 and 4)
d. During all sleep stages equally

Answer 19

c. During slow-wave sleep (stages 3 and 4)

Question 20

What do birds do about sleep during the time when they are migrating?

a. They fly during the day and sleep at night.
b. They fly at night and sleep during the day.
c. They eat during the day, fly at night, and suffer from sleep deprivation.
d. They eat during the day and fly at night, but decrease their need for sleep.

Answer 20

d. They eat during the day and fly at night, but decrease their need for sleep

Question 21

If we want to predict how many hours a day some species sleeps, which of these questions would be most helpful in making that prediction?

a. What color is the animal?
b. Does the animal live north or south of the equator?
c. What does the animal eat?
d. How intelligent is the animal?

Answer 21

c. What does the animal eat?

Question 22

Which of the following occurs during sleep?

a. The brain “plays back” certain experiences of the day but more slowly.
b. Certain synapses become weakened, enabling others to stand out by contrast.
c. Synapses corresponding to the experiences of the day become strengthened.
d. Overall brain activity increases.

Answer 22

b. Certain synapses become weakened, enabling others to stand out by contrast.

Question 23

Of the following groups, which one tends to spend the highest percentage of sleep in the REM stage?

a. Infants
b. Those who sleep only a few hours per night
c. Prey animals, such as sheep and horses
d. Teenagers

Answer 23

a. Infants

Question 24

On which of the following points do the activation-synthesis hypothesis and the clinico-anatomical hypothesis agree?

a. Dreams are disguised representations of unconscious wishes.
b. Activity from the pons is essential to the formation of dreams.
c. Dreams begin with the brain’s spontaneous activity combined with recent memories and any information the brain is receiving from the senses.
d. If we have enough information about a person’s recent experiences and current surroundings, we can predict the content of the dreams.

Answer 24

c. Dreams begin with the brain’s spontaneous activity combined with recent memories and any information the brain is receiving from the senses.

Question 25

What evidence indicates that humans have an internal biological clock?

Answer 25

People who have lived in an environment with a light–dark schedule much different from 24 hours fail to follow that schedule and instead become wakeful and sleepy on about a 24-hour basis

Question 26

Why do people at the eastern edge of Germany awaken earlier than those at the western edge on their weekends and holidays?

Answer 26

The sun rises about half an hour earlier at the eastern edge than at the western edge. Evidently, the sun controls waking–sleeping schedules even when people follow the same clock time for their work schedule.

Question 27

What evidence strongly indicates that the SCN produces the circadian rhythm itself?

Answer 27

SCN cells produce a circadian rhythm of activity even if they are kept in cell culture isolated from the rest of the body. Also, when hamsters received transplanted SCN neurons, their circadian rhythm followed the pattern of the donor animals.

Question 28

How does light reset the biological clock?

Answer 28

A branch of the optic nerve, the retinohypothalamic path, conveys information about light to the SCN. The axons comprising that path originate from special ganglion cells that respond to light by themselves, even if they do not receive input from rods or cones.

Question 29

Someone who is blind because of cortical damage can still synchronize his or her circadian rhythm to the local pattern of day and night. Why?

Answer 29

If the retina is intact, melanopsin-containing ganglion cells can still send messages to the SCN, resetting its rhythm

Question 30

How do the proteins TIM and PER relate to sleepiness in Drosophila?

Answer 30

The proteins TIM and PER remain low during most of the day and begin to increase toward evening. They reach high levels at night, promoting sleep. They also feed back to inhibit the genes that produce them, so that their level declines toward morning.

Question 31

What do large, slow waves on an EEG indicate?

Answer 31

Large, slow waves indicate a low level of activity, with much synchrony of response among neurons.

Question 32

How can an investigator determine whether a sleeper is in REM sleep?

Answer 32

Examine EEG pattern and eye movements.

Question 33

During which part of a night’s sleep is REM most common?

Answer 33

REM becomes more common toward the end of the night’s sleep.

Question 34

Why do most antihistamines make people drowsy?

Answer 34

Two paths from the hypothalamus—one to the basal forebrain and one to the pontomesencephalon—use histamine as their neurotransmitter to increase arousal. Antihistamines that cross the blood–brain barrier block those synapses.

Question 35

What would happen to the sleep–wake schedule of someone who lacked orexin?

Answer 35

Someone without orexin would alternate between brief periods of waking and sleeping.

Question 36

What would happen to the sleep–wake schedule of someone who took a drug that blocked GABA?

Answer 36

.Someone who took a drug that blocks GABA would remain awake. (Tranquilizers put people to sleep by facilitating GABA.)

Question 37

Someone who has just awakened sometimes speaks in a loose, unconnected, illogical way. How could you explain this finding?

Answer 37

People often awaken from a REM period, because REM is abundant toward morning when people usually awaken. Different brain areas don’t wake up all at once. Shortly after awakening, parts of the brain may still be in a REM-like state, and thinking may have an illogical, dreamlike quality.

Question 38

What kinds of people are most likely to develop sleep apnea?

Answer 38

Sleep apnea is most common among people with a genetic predisposition, old people, and overweight middle-aged men.

Question 39

What is the relationship between orexin and narcolepsy?

Answer 39

Orexin is important for staying awake. Therefore, people or animals lacking either orexin or the receptors for orexin develop narcolepsy, characterized by bouts of sleepiness during the day.

Question 40

What kind of animal tends to get more than the average amount of sleep?

Answer 40

Predators get much sleep, and so do species that are unlikely to be attacked during their sleep (such as armadillos).

Question 41

What might one predict about the sleep of fish that live deep in the ocean?

Answer 41

The deep ocean, like a cave, has no light and no difference between day and night. These fish might not need to sleep because they are equally efficient at all times of day and have no reason to conserve energy at one time more than another.

Question 42

Does sleep improve memory by strengthening or weakening synapses?

Answer 42

The evidence so far points to weakening the synapses that were not strengthened during the day. Weakening these less relevant synapses enables the strengthened ones to stand out by contrast.

Question 43

What kinds of individuals get more REM sleep than others? (Think in terms of age, species, and long versus short sleepers.)

Answer 43

Much REM sleep is more typical of the young than the old, and of those who get much sleep than those who get little.

Question 44

What is a key point of disagreement between the activation-synthesis hypothesis and the clinico-anatomical hypothesis?

Answer 44

The activation-synthesis hypothesis puts much more emphasis on the importance of the pons.

Question 45