Sleep & Consciousness

Question 1

What is consciousness?

Answer 1

awareness of ourselves, our internal states and our surroundings

Question 2

What is considered the “gatekeeper” of our consciousness?

Answer 2

attention

Question 3

_____ is the default state of our consciouness

Answer 3

“Alertness”

Question 4

True or False: one must be alert if they are awake

Answer 4

False - alertness and wakefulness are related states but are not identical

Question 5

What is an EEG

Answer 5

an electroencephalogram - it is a recording at the scalp of general patterns in electrical signals (ie brainwaves)

Question 6

Alertness and arousal are controlled by what group of structures within the brainstem?

Answer 6

the reticular activating system, RAS

Question 7

When a person is awake AND alert, their EEG shows what type of brainwaves?

Answer 7

beta waves

Question 8

When a person is awake, but also in a relaxed or daydreaming state, their EEG shows what type of brainwaves?

Answer 8

alpha waves

Question 9

Alpha waves are the first indicator that……

Answer 9

a person is ready to drift off to sleep

Question 10

How many stages of sleep are there?

Answer 10

4 stages of Non-REM sleep, and then REM sleep

Question 11

What characterizes Stage 1 sleep?

Answer 11

• EEG is dominated by theta waves
• person becomes less responsive to stimuli
• person has fleeting thoughts
• hypnagogic hallucinations
• hypnic jerks

Question 12

What is another term for “neural oscillations?”

Answer 12

brainwaves

Question 13

What characterizes Stage 2 sleep?

Answer 13

• increased relaxation w/decreased HR, respiratory rate, BP and body temperature
• theta waves still present, but K complexes and sleep spindles are now introduced

Question 14

What are believed to aid in suppressing cortical arousal and memory consolidation?

Answer 14

sleep spindles and K complexes

Question 15

What characterizes Stage 3 sleep?

Answer 15

• also called “slow wave sleep”

- introduction of delta waves

Question 16

What characterizes Stage 4 sleep?

Answer 16

• transition into deep sleep

- EEG is almost entirely theta waves

Question 17

What is REM sleep?

Answer 17

sleep consisting of rapid eye movements

Question 18

What stage is called “paradoxical sleep” and why?

Answer 18

the REM stage, because your body is nearly paralyzed, but your mind is quite active with bursts of EEG activity

Question 19

How long is each sleep cycle (passing through non-REM and then REM stages)?

Answer 19

roughly 90 minutes

Question 20

On average, how many sleep cycles does a person complete each night?

Answer 20

roughly 4-5

Question 21

True or False: a person goes through each sleep cycle in chronological order

Answer 21

False - it may happen in sequence (1, 2, 3, 4, REM), but it is also possible to jump between various stages while sleeping

Question 22

What cycles tend to occur most during the first few hours of sleep?

Answer 22

slow wave sleep (ie stages 3 and 4)

Question 23

What cycles tend to occur right before you wake up?

Answer 23

REM sleep

Question 24

What is our “circadian rhythm?”

Answer 24

this is the waxing and waning of alertness over the 24-hour day

Question 25

What is another term for “circadian rhythm?”

Answer 25

our “biological clock:

Question 26

What is the SCN?

Answer 26

the suprachiasmatic nucleus, which is the nuclei within the hypothalamus; the SCN regulates physiologic phenomena such as body temperature and hormone release

Question 27

How do we get sleepy when it gets dark?

Answer 27

darkness causes the SCN to signal the pineal gland to start producing and releasing melatonin; as melatonin levels rise you feel tire

bright light inhibits the release of melatonin

Question 28

True or False: artificial indoor lighting can also sometimes be bright enough to prevent the release of melatonin?

Answer 28

True - this is why some studies suggest that turning off mobile devices an hour before bedtime can improve your sleep

Question 29

What makes up the largest proportion of sleep?

Answer 29

non-REM

Question 30

Why do dreams only seem abnormal upon waking?

Answer 30

because during REM sleep, activity in our prefrontal cortex is decreased

Question 31

On average, how long do most dreams last?

Answer 31

5-20 minutes at a time

Question 32

What was Freud’s theory on dreams?

Answer 32

dreams are a way of expressing our unconscious drives and desires that are difficult to express

Question 33

What did Freud say is the difference between manifest content and latent content of dreams?

Answer 33

manifest content are the plotlines of our dreams

latent content are the symbolic versions

Question 34

What is REM rebound?

Answer 34

Missing REM sleep one night results in an increase in REM sleep later to make up for the deficit

Question 35

What is the activation-synthesis theory of dreams?

Answer 35

dreams are byproducts of brain activation during REM sleep

Question 36

What is somnambulism?

Answer 36

sleepwalking

Question 37

Distinguish between nightmares and night-terrors

Answer 37

nightmares: occur during REM sleep, closer to morning

night-terrors: occur during stage 3 sleep, person may sit up, walk around, babbly and appear terrified, although none of this is remembered the next morning

Question 38

What is the persistent trouble falling or staying asleep?

Answer 38

insomnia

Question 39

What is periodic, overwhelming sleepiness during waking periods?

Answer 39

narcolepsy

• usually lasts ~ 5 minutes and can occur at any time
• causes may be linked to neurotransmitters linked to alertness

Question 40

What is sleep apnea?

Answer 40

causes people to stop breathing intermittently while sleeping, usually lasting ~ 1 minutes

-can occur several hundred times per night, preventing you from entering slow wave sleep