Sleep

Question 1

what are the two main theories for why we sleep

Answer 1

• restoration/recuperation theories
• circadian theories

Question 2

what does the restoration theory of sleep propose

Answer 2

sleep restores homeostasis and supports brain plasticity

Question 3

what does the circadian theory of sleep suggest

Answer 3

sleep is needed for internal timing and evolutionary adaptation to protect us during night time

Question 4

how much of our lifetime do we spend sleeping

Answer 4

around 170,000 hours, or around 20 years.

Question 5

what does circadian mean

Answer 5

circa = about, diem = day. a biological rhythm of about 24 hours

Question 6

what is a zeitgeber

Answer 6

an environmental cue (like light) that helps entrain circadian rhythm

Question 7

what does entrainment mean

Answer 7

control the timing of

Question 8

what happens to circadian rhythms without zeitgebers

Answer 8

people experience a free-running cycle, often slightly longer than 24 hours

Question 9

what hormone is secreted at around 21:00 to help regulate sleep

Answer 9

melatonin

Question 10

what did Wright et al. (2013) - camping vs. normal environment study show

Answer 10

biological clocks resynchronise to natural light

Question 11

how does artificial light affect sleep

Answer 11

it delays circadian timing and affects melatonin secretion

Question 12

what is jet lag

Answer 12

sleep disruption due to crossing time zones and change in zeitgebers

Question 13

which is harder: eastward or westward travel?

Answer 13

eastward (phase advance)

Question 14

why is westward travel easier than eastward

Answer 14

because its easier to stay up later than to fall asleep earlier

Question 15

how does shift work disrupt sleep

Answer 15

zeitgebers remain constant, but work hours shift. sleep is shorter if during the day

Question 16

health risks of shift work and jet lag

Answer 16

• diabetes
• depression
• obesity
• cancer

Question 17

what are the 4 stages of sleep

Answer 17

stage 1
stage 2
stage 3
stage 4 (non-rem)
followed by REM

Question 18

what is slow wave sleep

Answer 18

stages 3 and 4 - deep sleep with delta waves

Question 19

what are alpha waves associated with

Answer 19

relaxed wakefulness

Question 20

freq of alpha waves

Answer 20

8-12Hz

Question 21

what are beta waves

Answer 21

low amplitude, high frequency waves during alert wakefulness

Question 22

freq of beta waves

Answer 22

13-30Hz

Question 23

what characterises stage 2

Answer 23

sleep spindles and k complexes

Question 24

what are PGO waves

Answer 24

bursts from the pons to the LGN and occipital cortex during REM

Question 25

what are 3 consistent effects of sleep deprivation

Answer 25

increased sleepiness, mood disturbance, poor vigilance performance

Question 26

what are micro sleeps

Answer 26

brief episodes (2-3 seconds) of sleep while awake

Question 27

how long did Randy Gardner stay awake in (1965)

Answer 27

11 days

Question 28

what is insomnia

Answer 28

difficulty falling asleep or staying asleep

Question 29

what is sleep apnea

Answer 29

interrupted breathing during sleep, often airway obstruction

Question 30

what is narcolepsy

Answer 30

sudden sleep attacks during the day; includes cataplexy, sleep paralysis, and hallucinations

Question 31

what neurotransmitter is lacking in narcolepsy

Answer 31

orexin (hypocretin)

Question 32

what is manifest content

Answer 32

actual dream content

Question 33

what is latent content

Answer 33

hidden, unconscious meaning

Question 34

what is the activation synthesis theory of dreaming

Answer 34

dreams are the cortex's attempt to make sense of random brainstem activity (Hobson and McCarley, 1977)

Question 35

what happens in REM rebound

Answer 35

increased REM after deprivation

Question 36

what % of participants report vivid dreams during REM (dement and kleitman, 1957)

Answer 36

80%

Question 37

what structure is key for regulating circadian rhythms

Answer 37

suprachiiasmatic nucleus (SCN) of the hypothalamus

Question 38

what hormone is secreted by the pineal gland to induce sleepiness

Answer 38

melatonin

Question 39

what is ARAS

Answer 39

ascending reticular activating system - controls wakefulness

Question 40

what did von economo discover would happen as a result of damage to anterior hypothalamus

Answer 40

insomnia

Question 41

what would happen as a result of damage to posterior hypothalamus

Answer 41

hypersomnia

Question 42

what is the passive theory of sleep

Answer 42

sleep occurs due to reduced sensory input (Bremner, 1937)

Question 43

what did EEG studies show in cerveau isole preparation

Answer 43

continuous slow wave sleep

Question 44

what happens at 9pm in circadian rhythm

Answer 44

melatonin secretion starts

Question 45

what time is deepest sleep circadian rhythm

Answer 45

2am

Question 46

what time is body temp lowest in sleep

Answer 46

4:30am

Question 47

what time does the sharpest BP rise happen

Answer 47

6:45am

Question 48

what time does melatonin secretion stop

Answer 48

7:30am

Question 49

what happens at 10am circadian rhythm

Answer 49

highest alertness

Question 50

what time do we have the best coordination

Answer 50

2:30pm

Question 51

what time do we have the fastest reaction time

Answer 51

3:30pm

Question 52

what time are we the strongest in the day

Answer 52

5pm

Question 53

what happens at 6:30pm circadian rhythm

Answer 53

highest BP

Question 54

what time do we have the highest body temp

Answer 54

7pm

Question 55

what does EEG measure

Answer 55

brainwave activity near the electrodes

Question 56

what does EOG measure

Answer 56

eye movements

Question 57

what does EMG measure

Answer 57

muscle activity (commonly in the neck)

Question 58

someone travels eastbound and goes to bed at 10pm and wakes up at 6am, but this feels like?:

Answer 58

feels earlier - like going to bed at 7pm and waking up at 3am

Question 59

what are sleep spindles

Answer 59

brief bursts of 12-14Hz waves in stage 2 sleep

Question 60

what are K complexes

Answer 60

sharp, high amp waves in stage 2, in response to stimuli

Question 61

what is the frequency of delta waves

Answer 61

0.5-4Hz (very slow, deep sleep waves in stage 3-4)

Question 62

what is cataplexy

Answer 62

sudden muscle weakness during wakefulness

Question 63

what does EEG stand for

Answer 63

Electroencephalogram — brain activity

Question 64

what does EOG stand for?

Answer 64

Electrooculogram — eye movement

Question 65

what does EMG stand for

Answer 65

Electromyogram — muscle activity