wakefulness and sleep

For a normal person, about how long does a cycle of sleep (from stage 1 to stage 4 and back again) last?

90 minutes

It is possible to determine a person's stage of sleep through which kinds of monitoring?

EEG and eye movements

PGO waves are associated with which of the following?

REM sleep

The postural muscles are most relaxed during:

REM sleep.

What is a strong piece of evidence that the suprachiasmatic nucleus (SCN) generates the circadian rhythm?

SCN neurons generate a circadian rhythm of impulses even after removal from the brain.

What is one of the contradictions in "paradoxical" sleep?

The brain is very active, while many of the muscles are deeply relaxed.

If a particular area of the brain is active when learning how to play a new video game, what would happen most likely happen if you were to sleep shortly thereafter?

The same areas of the brain are active again during sleep

The 'Per' and 'Tim' proteins accumulate during the day until they cause sleepiness. What prevents them from continuing to accumulate at night?

When the proteins reach a high level, they turn off the genes that produce them.

An electroencephalograph displays:

a net average of all the neurons' potentials.

If you wanted to go to sleep at 11 pm, the best time to take melatonin would be:

about 9 pm

The relationship between sleep stage and dreaming is that dreams:

are more frequent and more vivid in REM sleep.

Some drugs used to treat allergies may produce drowsiness if they:

block histamine

The proteins 'Per' and 'Tim', originally discovered in insect but now found in mammals also, influence circadian rhythms by:

building up during the day and declining during sleep

According to the evolutionary perspective of sleep, the primary function of sleep is to:

conserve energy.

If suprachiasmatic nucleus neurons are disconnected from the rest of the brain, they:

continue to produce activity that follows a circadian rhythm

A "Zeitgeber" is a(n):

environmental cue that resets a biological clock

What does "endogenous" mean?

generated from within

Which of the following is NOT a common characteristic of narcolepsy?

involuntary movements of the limbs during sleep

What do the EEG waves look like when brain activity is "desynchronized"?

irregular waves with low amplitude

During REM sleep, the EEG shows:

irregular, low-voltage fast waves.

What is the principal Zeitgeber for land animals?

light

What is the best way to objectively determine if someone is asleep?

monitor brain waves

People with REM behavior disorder:

move vigorously during REM, apparently acting out their dreams.

Which of the following has often been interpreted as an intrusion of REM sleep into wakefulness?

narcolepsy

EEG waves are larger when brain activity decreases because:

neurons are becoming more synchronized.

The onset of REM sleep begins with activity in the:

pons.

During REM sleep, neuronal activity decreases in the:

primary visual cortex and the motor cortex

Suppose you fell into a cave and lost your watch. Without any time cues, your circadian rhythm would:

remain relatively stable

A small branch of the optic nerve which extends directly from the retina to the SCN in the hypothalamus is called the:

retinohypothalamic path

Which of the following is most clearly under the control of a circadian rhythm in most animals?

sleep

With each succeeding stage of sleep (from 1 to 4):

slow, large-amplitude waves increase in number.

If you were awakened every time you entered REM sleep for a few days, and then were permitted to sleep without interruptions, you would:

spend about 50 percent more time in REM sleep than usual

Typically, a person who falls asleep enters:

stage 1 and slowly progresses through stages 2, 3 and 4 in order.

A key area of the hypothalamus, particularly important in the regulation of the biological clock, is the:

suprachiasmatic nucleus.

According to the activation-synthesis hypothesis, what do dreams reflect?

the brain's attempt to make sense of spontaneous neural activity

Over the course of a normal night's sleep, how does the sleep cycle change?

the duration of stage 4 decreases and REM sleep increases

In rats, after a number of days of sleep deprivation:

the immune system begins to fail.