sleep and dreams Flashcards
(32 cards)
evaluate crick and mitchisons reorgansational theory of sleep
good explaination why we cant remember dreams
clear theory why rem is important
largely based in the computer analogy - lacking validity
much more evidence shows rem strengthens memories
doesnt explain why most dreams follow a narrative and make sense
analyse the reorganisational theory of sleep and dreams
dolphins and echidnas - large brains and no rem sleep
supported by neural network computer models of learning
walker - finger tapping - sleep reliably encodes memories
seehagen - babies learn a new action better if they had a nap. better recall
rasch and born - when asked to supress memories before sleeping, people remembered better after
ptsd
bjork - evidenece the brain has unlimited space for memories
oswald - yes as rem had a key purpose but no as he says it is to restore the biological parts of the brain
what is the restorational theory of sleep and dreams
we dream in order to forget. we use reverse learning to forget parastic memeories which would otherwise take up space in the brain and cause a large and unefficent brain. this allows the neuropathways for adaptive memories to be strengthened and easier to recall.
what is the restoration theory of sleep and dreams
we need nrem sleep to restore and repair physical aspects such as resources of energy and repairs to cells, and rem sleep to repair the brain in ways such as replenishing stores of neurotransmitters and repairing neuropathways.
evaluate oswalds theory
the are many real life examples of low sleep levels resulting in poorer performances in humans, for example peter tripp.
very simplisitic - why do we have multipule stages of sleep
- probably has multipule functions not js restoration (like info - processing)
brain is very active in rem sleep, contridicts the idea that rem sleep is the best time for the brain to repair itself
analyse the restorational theory of sleep
shapiro - marathons runners
peter tripp - hallucinations
new borns can sleep for 20 hours a day (50% rem) which is needed for the rapid growth and development after birth
following brain injuries, patients spend longer in rem sleep for an av of 6 weeks, suggesting it is being used to repair the brain
horne and harley - hairdryers
peter tripp - body didnt break down
teenagers dont have an increase of nrem during puberty
cell repairs occur all the time - not confined to sleep - resting not sleeping
comas if brain trauma and sleep before exams
aim of d and k
to investigate which stage of sleep dreaming occurs in and if the eye movement in rem sleep correlates to dream content
method of d and k
9 adults (7m 2f) can to the lab to sleep and were awoken during the night several times. have you been dreaming and how long? connected to an eeg. no caffiene or alcohol
results of d and k
80% in rem sleep while dreaming
there was a link between eye movement and dream content eg vertical eye movement - climbing up a ladder
conclusions of d and k
we can accurately judge the length of our dreams
we dream in rem stage of sleep
eye movement reflects what we are dreaming about
dreams can be objectively measured using eegs
evaluate d and k
lab
breakthrough study - other more natural studies confirmed rem = dreams
small biased sample
some parts didnt refrain
other studies found no correlation between eye movement and dream content
analyse d and k
cziesler - greater ev then d and k but less reliability
peter tripp
wish fulfilment theory as id dominant while asleep
relates to memory consolidation as crick an dm says this happens in rem sleep
could help sleep disorders as could guide the creation of inventions to improve dream content and length
developed a way of being able to objectively study dreams
later studies used the procedure to establish the purpose of rem sleep
aim of czeisler
to evaluate if exposure to bright light at night and darkness at day would help treat maladapatation to nightshift work
czeisler methodology
8 men - no nightwork or sleep disorders
1 week baseline, second week men lived at home then came into lab for “work”.
control group had a normal light (150), other under bright morning light (120000). measurments were taken.
results of czeisler
biological and alterness and cognitive abilities shifted by 9 hrs (circadian rhythm)
czeisler conclusions
circ rhytm can be altered using bright light exposure in js a few days
maladaptaion to night shift work can be treated with bright light exposure
can help health and productivity at night shifts
help make night shift workers more alert and work better
evaluate czeisler
field
robust findings as multipule assessments were used
possible extr variables
small biased sample
analyse czeisler
boivin - agree w light - more participants and used 4 light levels
d and k
demonstrated maladaptation can be fixed
highlighted possible implications for industries (productivity and safety)
highlighted health issues from sleep deprivation
little hans aim
to provide evidence for the contraversial odiepus complex
little hans method
case study of one wee boy whos dreams were recorded and sent to freud by his dad
results of little hans
married to his mum and had a family. desire for his mum (repression)
large giraffe trampling a small giraffe. fear and hostility towards his dad. (displacement)
evaluate little hans
cant generalise to one patient
previous knowledge
friends so distrort to provide evidence
not universal
provided evidence
role of rem sleep
smith 1999
consolidate emotional memories - increase of activity in the amygdala
karni - speed perception task
infants - rem used for development consolidation of procedural memories
role of nrem sleep
smith 1999
tucker nrem naps improved declaritive memories and new information
