sleep (e4) Flashcards
what are our biological rhythms tied to?
the passage of time
what do rhythms help us anticipate?
changes in the environment
circadian rhythms
24 hour biological cycles that influence regulation of sleep and other physical responses
exposure to light readjusts biological clocks by what method
affective activity of the hypothalamus
what part of the brain is a circadian clock
hypothalamus
suprachiasmatic nucleus (SCN)
- influenced by light
- controls release of melatonin in the pineal gland (makes us sleepy)
- light reaches SCN directly in mammals
what controls the release of melatonin
suprachiasmatic nucleus
where is melatonin released
pineal gland
how many stages are there for EEG and sleep?
5
stage 1
5-10 minutes, EEG theta waves
stage 2: brief bursts of higher-frequency brain waves
k-complex and sleep spindles
k-complex
sharp waves, temporal inhibition of neuronal firing, occur after sudden interruption within the sleeper’s environment (noise)
sleep spindles
generated in the thalamus, 500 ms, inhibition, greater number of sleep spindles means more refreshed to perform on a learning task
stages 3 and 4
slow wave sleep, high amplitude but low frequency delta waves, synchronization of low-waves, reduction of sensory input
stage 5: REM sleep
rapid eye movement, high frequency beta waves in some areas, most dreams occur during this stage (can also happen in stages 3/4)