Sleep, dreams, Freud Flashcards
on average, how much of our lives do we spend sleeping?
36%
circadian rhythms
rhythmic cycles corresponding to roughly 24-hour periods and occur naturally
how do we know that our circadian rhythm is 24 hours
people put into room without clocks or windows, and they go to bed later and wake up later every day
original studies: let people have electric lights, presence of lights affect biology of sleep
how do we measure sleep
EEG: placing electrodes on scalp to measure electrical activity; rough estimates of psychological states
also need to measure muscle electrical activity and eye movement (ECG)
State 1 of sleep
brief transition stage when first falling asleep (hypnagogia), slower muscle activity
theta waves
State 2 - 4
2: sleep spindles and K complex
3/4: delta waves
slow-wave sleep
deeper stages of sleep
characterized by increasing percentage of slow, irregular, high-amplitude delta-waves
cycle back stage of sleep
after about 90 minutes after 3/4 stage, sleep lightens and returns to stage 2 then REM
(1 -> 2 -> 3 -> 4 -> 3 -> 2 -> REM -> 2 …)
4-5 cycles are typical
REM sleep
characterized by EEG patterns that resemble beta waves of alert wakefulness
muscles most relaxed / paralyzed
rapid eye movement
dreams
how does sleep walking occur (somnambulism)
the mechanism to paralyze muscles during REM does not get shut off
how is REM sleep waves different than awake brain waves
both are beta but REM has some sawtooth wave patterns
hypnagogia
transition from sleep to wakefulness
induce hallucinations, thoughts, dreams
how does sleep paralysis occur
mechanism for paralyzing muscles starts too early during hypnagogia
lucid dreaming
awareness that you are dreaming (REM) during a dream
how studies study lucid dreaming
studies show ability to communicate between dreamer and external observation
strapped goggles to people sleeping and shine light over eyes when they enter REM sleep and people sleeping would remember they were in a lab
participants would do a predetermined pattern of eye movement to let the scientists know that they know they are sleeping
functions of sleep for 2-3 year olds
brain grows rapidly (building + strengthening synapses during REM)
functions of sleep after 3+
switches from brain building to brain maintenance and repair
when people are lucid dreaming, how does time change
it does not
why do we sleep
conserve calorie energy (not plausible explanation)
restoration of body
memory consolidation and strengthening/neural synthesis
how much sleep do newborns need
16 hours
how much sleep do 6 year olds need
11-12 hours