14.3 - Effects of Sleep Deprivation Flashcards
Why is t difficult to measure the effects of sleep deprevation in an effective manner? (2 reasons for this, and implications)
STRESS
- most people who sleep little do so bc of stress, which has independent effects
- sleep deprivation procedures are often stressful - makes experiments troublesome
- so, we need to examine the effects of sleep deprivation carefully
What are the three predictions of recuperation theories n terms of sleep deprivation
- long periods of wakefulness will produce physiological and behavioural disturbances
- disturbances grow in proportion to sleep deprivation
- after long deprivation periods end, much of the missed sleep with be regained
Explain the Kleitman 1963 study on sleep deprived students
total sleep deprivation - similar effects between participants
- first night - read to studied with no problems until 3 AM, then got very sleepy, had to be kept awake
- next day, alert as long as they were active - second night couldn’t read or study, sleepiness was so severe, after 3 AM sleepiness was overpowering
- third morning, decrease in sleepiness, students could perform tasks as long as they were standing and moving
- third and fourth days were the same as the other nights, but sleepiness got more severe
- things did NOT GROW WORSE after the forth night, those who persisted went through the same cycle
Explain the case of Randy Gardner
tried to break the WR for longest hours of consecutive wakefulness
- researcher Dement joined the team
- Randy complained when his team mates didn’t let him close his eyes
- but his behaviour was not disturbed
- held a press conferences the last night (264 hours)
- conducted himself well
- slept only 14 hours the first night, then returned to his 8 hour schedule, which is typical
what have experimental studies of sleep deprivation in humans measured?
sleepiness, mood, cognition, motor performance, physiological function, molecular function
what are the three consistent effects of moderate sleep deprivation (3-4 hours less than normal sleep)?
- increase in sleepiness
- negative affect
- perform poorly on tests of sustained attention
what are the effects of sleep deprivation on complex cognitive functions?
inconsistent, so we study on simple, dull and monotonous tasks that are most sensitive to sleep dep.
- only some cognitive functions are susceptible
what are the cognitive functions that are immune to sleep deprivation?
logical deduction, critical thinking
what cognitive functions are disrupted by sleep deprivation?
executive function, which are dependent on the pfc
- includes. innovative, lateral and insightful thinking, as well as assimilating new information to update plans and strategies
what have many researchers claimed needs further investigation in the study of cognitive effects of sleep loss?
the degree to which deficits in. vigilance and motivation produced by sleep loss can be mistaken for cognitive deficits
what are the effects of sleep deprivation on physical performance?
inconsistent results, only a few measures are affected even after long periods of deprivation
what are the effects of sleep deprivation on physiology?
- reduced body tempt
- increased blood pressure
- decreases in aspects of immune function
- hormonal changes
- metabolic changes
what is the problem with interpreting the effects of sleep deprivation on physiology
- what study skirted this problem
little evidence they have any consequences on performance
- ex, decline n immune function has been discovered in sleep deprived volunteers, doesn’t really mean they would be more susceptible to infection, immune system is extremely complicated and a decline n one aspect is often compensated for by other changes
- Prather and colleagues (2015) - studied susceptibility to infection and illness directly
describe the Prather and colleagues (2015) study on illness and infection susceptibility and sleep deprivation
exposed 164 healthy volunteers to a cold virus, those who slept less than 6hrs/night were not more likely to get infected, but were more likely to get sick
- only correlation, can’t be proven certain yet
what are micro sleeps? when do they happen?
brief, 2-3 second sleeps during which eyelids droop and volunteers become less responsive to external stimuli even tho they remain sitting or standing
- after 2-3 days of continuous deprivation
what do micro sleeps disrupt? is tis only disrupted by micro sleeps?
vigilance, no, sleep deprived ppl wo micro sleeps also experience decreases in vigilance
why are the effects of sleep deprivation studies so odd?
- compared with other motivated behaviours (sex, hunger), sleep deprivation effects are minor and subtle
- performance deficits observed even after 64 hours of deprivation are eliminated in 4 hours
what is the caruosel apparatus
yoked control paradigm - when EEG activation says the experimental rat is sleeping, the disk which is the floor for both chambers rotates
- if the experimental rat does awake immediately it gets tossed into water
- the control is the same, but if it wakes it can avoid getting dunked by walking in the opposite direction of the disk
- experimental rats die in 12 days, yoked controls stay healthy
why are the findings of the carousel apparatus difficult to interpret?
the fact that sleep deprivation studies in humans haven’t really shown the same results - maybe repeatedly awakening the rats kills them bc it is stressful
what supports the ‘stress’ interpretation of the carousel apparatus findings?
- interpretation is consistent with the pathological problems observed in the experimental rats post mortem - swollen adrenal glands, gastric ulcers and internal bleeding
why might sleep deprivation be impossible to productively studied in humans
the unavoidable confounding effects of extreme stress
what are the two effects of rem sleep deprivation
- following deprivation, participants display REM rebound - more than usual amount of rem for the first 2 or 3 nights
- each successive night of deprivation, there is a greater tendency for participants to initiate REM - participants have to be awakened more and more often as the study goes on to keep them from getting the rem sleep
what is an example of the increased tendency to enter REM if we are deprived of it?
first night, participants had to be awakened 17 times to stop rem, but during the 7th, 67
what does the compensatory increase in REM following REM deprivation suggest (2)
- REM is regulated separately from slow wave sleep
2. REM serves a special function