PSY1003 SEMESTER 2 - WEEK 9 Flashcards
describe behavioural sleep characteristic
reduced motor activity or response to stimulations, stereotypic positions and easily reversible
what was Freuds interpretation of dream
triggered by unacceptable, and repressed wishes
explain activation-synthesis hypothesis
dreams due to cortex attempting to make sense of random brain activities
explain frequency and amplitude of EEG when alert, or relaxed
alert- high frequency (15-30Hz), low amplitude, ‘beta’
relaxed- medium frequency (8-12Hz), medium amplitude, ‘alpha’
during first stage of sleep, describe EEGs
transition from wake-sleep, muscles still active, gentle eyes movements
theta
3.5-7.5Hz
in stage 2/3, what happens to EEG
progressively get lower in frequency but higher in amplitude
in stage 3/4 what happen to EEG
delta, high amplitude, <3.5Hz
slow-wave, sleep walking/talking
how long does the sleep cycle last
90min
describe carosel animal studies in sleep deprivation
when EEG indicates rat asleep, floor move rat into water
dies after several days (post mortem show extreme stress)
what does sleep deprivation have little effects on
logical deduction, critical thinking, physical strength, motor performance
what does sleep deprivation have large effect on
EF = assimilating info, updating plan or strategy, innovative lateral insight thinking, reference memory
what can 3-4hr of deprivation in one night cause
increased sleepiness, disturbance on mood written tests, poor performance in vigilance test
what can 2-3 days of continuous deprivation cause
microsleep (nap of 2-3s)
what is impact of sleep deprivation on physiology
reduced temp, increase BP, decreased immune function, hormone change, metabolic change
explain why sleep deprivation can increase sleep efficiency
post-dep, most of lost stage4 regained. slow-wave sleep increase
short sleepers get as much slow-wave as long
nap without slow-wave doesn’t impact sleep
little sleepiness if repeatedly woke in REM
how do you study REM sleep deprivation, and what 2 consistent effects have shown
wake those in REM, then let them go back to sleep
1. go more rapidly to REM as dep increase, so need to wake them more frequently
2. REM rebound- spend more time in REM post-dep for first 2,3 nights
explain impact of sleep on depression
insomnia and hypersomnia
get less slow-wave sleep but no memory disruption
once taking anti-depressants, may not get REM sleep for years
how may sleep deprivation improve depression
total sleep deprivation for 1 night improve symptoms for 40-60% but no-one knows why
explain link between sleep deprivation and alzheimers
risk factor
sleep used as a waste clearing system- CSF moves through brain and remove waste products (eg; amyloid-B)
what is the recuperation theory of sleep
restoring homeostasis, energy levels to clear toxins
what is adaptation theory of sleep
internal 24hr timing mechanisms, programmed to sleep at night regardless of what happens during day
explain purpose of REM being to process explicit memory, but issues with this
process explicit memory?- inconsistencies, antidepressants REM-blocking don’t impact memory
explain default theory for purpose of REM
difficult to remain in non-REM
if wake sleeper in REM, stay awake for 15min
showed no sleepiness/REM rebounds next day suggesting no need for REM sleep if wakefulness sustitues
explain why purpose of REM may be brain development
70% REM newborn
30% REM 6 months
continues to decrease in adults
