sleep and dreaming Flashcards
define altered states of consciousness
forms of experience that depart from the normal subjective experience of the world and the mind
what is the hypnagogic state
preesleep consciousness
what is a hypnic jerk?
quiver/ jerk sense of dropping
what is hypnopompic state
postsleep consciousness.
define circadian rhythm
a naturally occuring 14-hour cycle
what happens to sleep when people go underground without clocks and why?
rest-active rhythm of 25.1 hours
people want to stay up a little later each night and wake up a little later each morning
what waves are high frequency activity?
beta- alertedness
which waves are low frequency activity
alpha- relaxation
what do EEG recordings show about waking
alternation between alpha and beta waves
what waves are present when awake?
beta
what waves are present when drowsy?
alpha
what waves are present during stage one sleep?
theta- frequency patterns even lower than alpha
what occurs in stage 2 sleep?
sleep spindles and K complexes–> these are short bursts of activity
when does the sleeper become more difficult to wake?
stage 2
what waves are present in stage 3/4 of sleep
delta waves
what waves are present in REM sleep?
sawtooth waves- high frequency
what do the waves in REM sleep suggest about activity of the mind?
it is as active as during waking
define REM
a stage of sleep characterized by rapid eye movements and high level of brain activity
what is REM sometimes known as
paradoxical sleep
what is an electrooculograph (EOG)
a device that measures eye movements
what do sleepers woken during REM sleep report?
having dreams more often than those woken in non-REM periods
what physically happens during REM sleep?
eyes move
pulse quickens
blood pressure rises
telltale signs of sexual arousal
what do measurements of muscle movement indicate about REM sleep?
the sleeper is very still
what % of people woken in REM sleep report dreaming
95%
how did Dement et al. find out about time perception during REM sleep
woke volunteers wither 5 or 15 mins into REM sleep
volunteers asked to guess how long in they had been woken. high accuracy
suggest that dreaming occurs in real time
do all dreams occur in REM sleep?
no but not as many and these dreams are less wild and more like normal thinking
what happens in the first hour of the night in sleep?
you fall from waking through the stages to the fourth and deepest stage of sleep (delta waves)
what do slow delta waves indicate about nerual firing
slow synchronised neural firing
what happens post the fist hour of sleep
you return to the lighter stages eventually reaching REM
is REM deeper or lighter than other stages?
lighter
how often does one cycle through REM and other stages of sleep through the night?
every 90 mins
what happens to periods of REM as the night goes on?
they get longer
what happens to stages 3 and 4 of sleep as the night goes on?
they disappear half way through the night
how do newborns sleep
often total +16 hours
sleep 6-8 times in 24 hours
what happens between 9 and 18 months?
napping cycle consolidates into sleeping through the night
how much sleep does the typical 6 year old need
11-12 hours
how much sleep does the average adult need?
7-7.5 hours
over a whole life time what is the sleep to awake ratio?
2 hours awake to one hour asleep
how long is the longest time awake?
11 days
when did the person who stayed awake for 11 days find it difficult to stay awake?
during the night
what were symptoms of staying up for 11 days?
main one was feeling tires along with a couple of minor hallucinatory experiences
what did observers note during the last night of being awake
randy spent last night in a penny arcade- he won easily suggesting extreeme sleep deprivation is not entirely debilitating
when randy went to sleep how long did he sleep for
14 hours and 40 mins and woke up essentially recovered
what research suggests that sleep following learning is essential for memory consolidation
when people learning a difficult perceptual task are kept up all night their learning of the task is whiped out. even after two nights of catch up sleep they show little indication of their initial training on the task.
what can sleep loss be?
fatal
what happens to rats who are forced to stay awake for vast peiods of time?
- trouble regulating body temp
- loose weight despite eating more than normal
- bodily systems break down
- usually die in 21 days
what can a few hours of sleep deprivation to to healthy young humans?
cumulative detrimental effect
- reducing mental acuity
- reduce reaction time
- increase irratibility
- increase depression
- increase accident and injury risk
what do studies of REM sleep deprivation indicate
- memory problems
- excessive aggression
REM is important psychologically