Sleep

Question 1

measurement of sleep

Answer 1

• eeg
• eoc
• emg

pre sleep alpha waves
bursts of 8-12hz activity in low amplitude, high frequency

Question 2

4 stages of sleeping

Answer 2

progressive - increase amplitude
sleep spindle - 1-2s bursts, 12-14hz waves
k complex - upward - downward deflection
decrease amplitude, increase frequency
REM sleep

Question 3

REM sleep

Answer 3

Dement
- 80% awaken during = dream recall
- 93% awaken during nREM - no dream recall
- nREM - isolated experiences
- REM - more narrative
Dement and Kleitman
- ppts awoken 5 or 15mins after REM onset
- asked how long theyd been dreaming
- correct 92/111 cases

Question 4

theories of sleep

Answer 4

1. recuperation theories - sleep restores homeostasis
2. evolutionary theories
   - sleep no reaction to homeostatic disruption
   - sleep evolved to prevent accidents at night
   - related to vulnerability and time spent eating

Question 5

sleep in animals

Answer 5

• all mammals and birds sleep
• others have periods of inactivity
• large species differ in sleep - not related to body size/ temperature
• sloths need 20hrs
• little effect of exercise on sleep duration in humans
• not consistent with recuperation
• difficulty concentrating on mental tasks

Question 6

effects of sleep deprivation - animals

Answer 6

• experimental rats died
• post mortem revealed swollen adrenal, gastric ulcers, internal bleeding

Question 7

effects of sleep deprivation - humans

Answer 7

:) increase in physiological disturbances
:( sleep must be regained - mostly in stage 1 and 2
Cireli - influences mood, molecular, and physiological function
executive function - assimilating changing info, updating plans, reference memory
BUT… recovery
Dement - 260 hours awake - 14 hours sleep

Question 8

depression and sleep deprivation - humans

Answer 8

Vogel et al - preventing REM acta as anti-depressant
Scherschlicht et al - 20 antidepressants
- all reduced REM
- most increased slow wave sleep
- preventing REM makes body want more
- causes transient rebound
- few cognitive or emotional effects

Question 9

brain areas involved in sleep

Answer 9

hypothalamus
Contain Von Economo - virus encephalitis lethargica
- difficulty sleeping - anterior damage
- difficulty awake - posterior damage
reticular system
Bremer
- cereau isole transection - slow wave sleep pattern
- encephala isole transection - normal sleep wake cycle
- wakefulness in-between

Mouzzi and Morgan
- stimulation of reticular formation of sleeping cats woke them
- low activity = sleep
- high activity = wake