Lecture 17- Sleep Flashcards
What are the 3 measurements of sleep w/ locations?
Electro-encephalogram (EEG) – Head Electro-oculogram (EOC)- Eye Electro-myogram (EMG) - Neck
What are pre-sleep alpha waves?
Bursts of 8-12 Hz activity in low amplitude/high frequency waves
What are the 3 stages of sleep EEG?
Progressive, sleep spindle, K complex
What is the progressive stage of sleep EEG?
Increase in amplitude, decrease in frequency
What is the sleep spindle stage of EEG?
1-2 sec bursts of 12-14 Hz waves
What is the K complex stage of sleep EEG?
Single large upward, then downwards deflection
What 2 aspects of the sleep EEG are involved in memory consolidation?
K complex, sleep spindle
What is the largest event in health human EEG?
K complex
What is caused by REM sleep?
Early studies indicate high rates of blood flow, oxygen consumption and neuronal firing
What did Dement (1978) say about REM sleep?
80% awakenings during REM sleep= dream recall
93% awakenings during nREM sleep= no dream recall.
What is caused by the nREM dream recall?
Isolated experiences
What is caused by REM dream recall?
More narrative
What are the 2 theories of sleep?
Recuperation theory
Evolutionary theory
What is the recuperation theory of sleep?
Being awake disrupts homeostasis but sleep restores this eg sleep restores energy.
What is the evolutionary theory of sleep?
Sleep is not a reaction to homeostatic disruption as it has evolved to prevent accidents and predation at night. We don’t need sleep to survive but we are motivated to have it.
What can be said about sleep in animals?
Large differences in sleep not related to body size temp eg sloths hardly move but sleep +20hrs/day. Not consistent with recuperation theories in sleep
What do recuperation theories say about effects of sleep deprivation?
Increases physiological/behavioural disturbances
BUT doesn’t suggest sleep must be regained after deprivation
What does Vogel et al (1975) say about sleep deprivation and depression?
Preventing REM sleep acts as antidepressant
What does Webb and Agnew (1967) say about depression and sleep deprivation?
Preventing REM sleep makes body want it more.
What does Brunner et al (1990) say about depression and sleep deprivation?
Deprivation of REM sleep causes a transient rebound
What happens with sleep deprivation in animals?
After several days, experimental rats died, post-mortem revealed swollen adrenal glands, gastric ulcers and internal bleeding. Suggests possible consequence of stress.
What are the 2 main brain areas involved in sleep?
Hypothalamus, Reticular system
How does the hypothalamus affect sleep?
Those who had difficulty sleeping had damage to anterior region.
Those who had difficulty staying awake had damage to posterior region.
