sleeping

Question 1

what are the three principles of sleep

Answer 1

• electroc-encephalogram - head
• electro-oculogram - eye
• electro-myogram - neck

Question 2

what are pre sleep alpha waves

Answer 2

bursts of 8-12Hz activity in low amplitude/high frequency waves

Question 3

what are the four stages of sleep EEGs

Answer 3

• progressive - increase in amplitude, decrease in frequency
• sleep spindle - 1 to 2s burst of 12-14 Hz waves
• K complex - single large upward, then downwards deflection

Question 4

what did Dement 1978 find about REM sleep

Answer 4

• 80% awakenings during REM sleep - dream recall
• 93% awakenings during non REM sleep - no dream recall
• non REM dream recall - isolated experiences
• REM dream recall - more narrative
• not associated with sleep walking due to atonia

Question 5

what did Dement and Kleitman 1975 find about REM

Answer 5

• pps awoken 5 or 15 min after onset of REM
  -asked how long they had been dreaming on basis of the dream
• pps correct 92/11 cases

Question 6

what are recuperation theories

Answer 6

• being awake disrupts homeostasis
• sleep restores this
• restores energy levels

Question 7

what are evolutionary theories

Answer 7

• sleep is not a reaction to homeostatic disruption
• sleep evolved to prevent accidents and predation at night
• sleep is like sex - we don’t need to but are still motivated to have it

Question 8

sleep in animals

Answer 8

• all mammals and birds sleep
• fish and amphibians have periods of inactivity too
• large species differences in sleep - not related to body size
• sloths hardly move yet need 20 hours of sleep
• little effect of exercise on sleep duration in humans
• not consistent with recuperation theories

Question 9

what are effects of sleep deprivation according to recuperation theory

Answer 9

increases in physiological/behavioural disturbances
- after deprivation, missed sleep must be regained
- deprivation influences mood, physiological function, molecular function
- effects on executive function - assimilating changing info, updating plans, reference memory
- but people will recover well after sleep deprivation

Question 10

what happened to Randy Gardner

Answer 10

• 260 hours awake
• 1st recovery night - 14 hours and then went back to normal

Question 11

depression and sleep deprivation

Answer 11

voget et al 1975 - preventing REM sleep acts as an antidepressant
- scherschlicht et al 1982 - examined effects of 20 antidepressants - all reduced REM sleep - most increased slow-wave sleep

Question 12

what is REM sleep for

Answer 12

• it is the default - hard to stay in non REM sleep
• it is more similar to wakefulness - people not tired after REM sleep deprivation

Question 13

effects of sleep deprivation in animals

Answer 13

• after several days - rats died
• post-mortem revealed swollen adrenal glands, gastric ulcers and internal bleeding
• consequence of stress and physical damage

Question 14

how is the hypothalamus involved in sleep

Answer 14

contantin von economo
- studied the brains of those who died from virus encephalitis lethargica
- victims who had difficulty sleeping - damage to anterior region
- victims who had difficulty staying awake - damage to posterior region

Question 15

what did Bremer 1936 find about brain areas involved in sleep

Answer 15

• cerveau isole transection - slow wave sleep pattern
• encephale isole transection - normal sleep wake cycle
• wakefulness area is somewhere between the 2
• the reticular system

Question 16

what id Mouzzi and Morgan find about the reticular system

Answer 16

• stimulation of the reticular formation of sleeping cats woke them
• area became known as the reticular activating system - low activity - sleep. high activity - wakefulness