Sleep

Question 0

Functions of sleep

Answer 0

Restoration
Evolution
Maintaining brain plasticity

Question 1

Basics of sleep

Answer 1

There are four stages of slow wave sleep
After slow wave sleep the body progresses into REM sleep.

Measured using an EEG

Question 2

Lifespan changes in length of REM sleep.

Answer 2

50% at birth

20% in old age

Question 3

Insomnia

Answer 3

Primary-lack of sleep main problem

Secondary- lack of sleep due to another problem.

Question 4

Sleep apnoea - related to a form of secondary insomnia

Answer 4

Apnoea- difficulties breathing when asleep

CSA apnoea -Brain forgets to send breathing messages
OSA apnoea- Narrowing of airways- upper airway relaxes

Brief inability to breathe- occurs when 1+ breath’s are missed
Continuous positive air pressure

Question 5

Sleep walking

Answer 5

Somnambulism

REM behaviour disorder

Question 6

Narcolepsy

Answer 6

Extreme sleepiness during the day

Cataplexy- muscles give way

Question 7

What three methods are used in distinguishing between the different stages of sleep?

Answer 7

EOG- Electrooculogram- measures eye movement
EEG- Electroencephalograph-measures brain waves
EMG- Electromyogram- measures muscle movement

Question 8

What happens in stage 1 of non rem sleep?

Answer 8

Person becomes relaxed, heart rate slows, eyes may roll and muscles relax. EEG shows theta waves.

Question 9

What happens in stage 2 of non rem sleep?

Answer 9

EEG pattern of sleep spindles- short bursts of high frequency activity.

Question 10

What happens in stage 3 of non rem sleep?

Answer 10

EEG shows dominant delta waves (large amplitude slow waves) sleep spindles occur less often.
Heart rate and body temperature drops.

Question 11

What happens in stage 4 of non rem sleep?

Answer 11

EEG shows mainly delta activity, deep sleep, hard to wake.

Question 12

What is the Restoration theory?

Answer 12

That sleep restores the body to full psychological and physical capacity

Oswald 1980- patients recovering show an increase in REM sleep. An increase in rem means an increase in protein synthesis.
Horne 1988- sleep deprivation-sleep recovery mainly happens in stage 4 and rem.

Question 13

Rem sleep deprivation case study-Empson 2002-

Answer 13

Researchers woke sleepers as soon as they entered rem sleep- if awoken and allowed to sleep again they normally go back into rem sleep - when then allowed to experience rem sleep they experienced 50% more rem sleep than normal.

Question 14

Evolutionary approach to the function of sleep

What are adaptive behaviours?

Answer 14

Behaviours that increase an animals chance of survival and reproduction.

Sleep= conservation of energy-most likely to survive

Question 15

Evolutionary approach to the function of sleep

What evidence is there for the evolutionary approach?

Answer 15

Small animals- high metabolic rates- lose heat fast- sleep longer than large animals

Zepelin&rechtschaffen 1974- 53 species- pos correlation between daily sleep length and species’ metabolic rate
Limitation- some large slow animals sleep a lot- sloth.

Question 16

Evolutionary approach to the function of sleep

Foraging- animals would sleep more if they had a nutrient rich diet

Answer 16

Extract more from food in less time and then sleep longer= conservation of more energy.
Evidence-panda just eats bamboo=poor quant of nutrients- eat 16 hours out of 24= eat 45kg= eat 8hrs-sleep 4.

Question 17

Evolutionary approach to the function of sleep

What should happen when food is scarce?

Answer 17

Evolutionary approaches would suggest that sleep time should increase- greater need to conserve energy

Evidence- Berger & Phillips 1995- animals do either increase sleep time or reduce body temperature.

Question 18

Evolutionary approach to the function of sleep

How do animals avoid predators?

Answer 18

Sleep in safe places in the hours of darkness when they are most vulnerable

Evidence- Allison & cicchetti 1976-
Correlational analysis- less sleep in day if they’re in a dangerous environment- 39 species - neg correlation between sleep and level of environmental danger

Question 19

Describe the 3 p model for insomnia…

Answer 19

Predisposition- a factor that increases likelihood of insomnia
Precipitation- a factor that triggers insomnia
Perpetuation- factors that have a maintaining effect on insomnia.

Question 20

What evidence is there for the 3p model and predisposition?

Answer 20

Spiel man 1987- affected by anxiety, depression, and emotions- study found insomniacs have an increased heart rate (in response to stress) and metabolic rate- increased physiological arousal assiciated with insomnia.

Some studies suggest worrying about insomnia is a factors other studies have found correlations opposing a personality alignment.

Question 21

What happens in rem sleep?

Answer 21

High frequency, small amplitude beta waves
EOG= rapid eye movement
EMG= muscles completely relaxed
EEG= similar to person awake= heart rate and respiration speed up
-body acts as if paralysed= paradoxical sleep

Question 22

Dreams occur most often in….

Answer 22

REM SLEEP

Question 23

What order do the stages of sleep happen in?

Answer 23

1-2-3-4-3-2

Question 24

Children have the most rem sleep when….

Answer 24

They are a foetus,

Question 25

Horne suggests that rem sleep helps…

Answer 25

Stimulate the brain in the foetus, when they are in the ‘real’ world it is replaced by outside world stimulation.

Question 26

Up to the age of 45 what percentage of sleep is REM?

Answer 26

15-25%