sleep Flashcards
(23 cards)
What are the 3 principle measures of sleep?
-EEG = Electro-encephalogram (head)
-EOC = Electro-oculogram (eye)
-EMG = Electro-myogram (neck)
What are pre-sleep alpha waves?
-Bursts of 8-12Hz activity in low amplitude and high frequency waves
There are 4 stages of sleep EEG, what are the main changes that occur
1: Progressive
2: Sleep spindle
3: K complex
What does ‘Progressive’ mean?
-Increase in amplitude
-Decrease in frequency
What does ‘Sleep spindle’ mean?
-1/2 burst of 12-14Hz waves
What does ‘K complex’ mean?
-Single large upward THEN downward deflection
-Sharp wave
How long does each cycle last?
-Around 90 minutes
What is stage 1 typically associated with?
-Periods of REM (rapid eye movement)
-Lack of core-muscle tone
What typically is associated with REM sleep?
-Dreaming
What was the procedure of Dement and Kleitman (1975) study in regards to REM sleep?
-Measured rapid eye movement
-Ppts awoken 5/15 mins after onset of REM
-Asked how long they’d be dreaming, either 5 or 15 mins
What was the results of Dement and Kleitman (1975) study in regards to REM sleep?
-80% awakenings in REM = dream recall
-93% awakenings in nonREM = no dream recall
-nonREM recall = isolated experience e.g. falling
-Ppts were correct 92/111 cases
What are the two different theory types of sleep?
-Recuperation
-Evolutionary
Describe recuperation theories
-Being awake disrupts homeostasis
-Sleep restores this e.g. energy levels
Describe evolutionary theories
-Sleep isn’t a reaction to disruption of homeostasis
-Sleep evolved to prevent accidents at night
-Don’t need sleep to stay alive but we are motivated to have it
What has been found in regards to sleep in animals?
-Large species differences in sleep -> aren’t related to body size or temp
-Sloths barely move but need 20hrs a day
What did Youngstedt and Kine (2006) suggest?
-Little to no effect of exercise on sleep duration in humans
How does sleep in animals link to the theories?
-Not consistent with recuperation theories
-Consistent with evolutionary = sleep is related to how vulnerable you are asleep and how much time you spend eating a day
What can deprivation influence (Cirelli, 2006)?
-Mood
-Physiological functions
-Molecular function
Do people recover well after sleep deprivation (Dement, 1978) ?
-260 hours awake
-1st recovery night = had 14 hours sleep
-Back to normal
What is the link between depression and sleep deprivation?
-Vogel et al. (1975)
-Preventing REM sleep acts as an antidepressant
-Scherschilicht et al. (1982)
-Examined effects of 20 antidepressant
-All reduced REM sleep
What is REM sleep for?
-Default = it’s quite hard to remain in nonREM sleep
-Similar to wakefulness = people aren’t tired after REM sleep deprivation
What are the effects of sleep deprivation in animals?
-Whenever experimental rat fell asleep, they would be awoken by dunking in water
-After days, experimental rats died
-Post mortem = revealed swollen adrenal glands, gastric ulcers and internal bleeding
How is the hypothalamus involved in sleep?
-Contantin von Economo = studied brains of those who died from virus ‘encephalitis lethargica’
-Victims who struggled sleeping had damage to anterior region
-Victims who struggled staying awake had damage to posterior region
