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Flashcards in 3. Sleep Deprivation Deck (14)
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1
Q

reasons for sleep deprivation

A
  • shift work
  • lifestyle (24/7 society)
  • family commitment (young children)
  • anxiety (increased arousal)
  • stimulants
  • sleep
2
Q

what are the signs of sleep deprivation

A
  • difficulty making simple decisions (easy options)
  • difficulty concentrating
  • falling asleep (napping)
  • feel hungry
  • more emotional
  • negatively effects reproductive system (quality of sperm)
3
Q

what is sleep deprivation?

A
  • total sleep deprivation (TSD)
  • partial sleep deprivation (PSD)
  • sleep fragmentation
  • not insomnia (struggle to get to and maintain sleep)
  • sleep deprivation is where we actively restrict our sleep by going to bed late and/or waking up early
4
Q

total sleep deprivation (TSD)

A
  • long term = > 45h
  • short term = < 45h
  • difficult to run studies without the use of stimulants as people take microsleeps (dont even know they are doing it) - ethical issues
5
Q

partial sleep deprivation (PSD)/restricted sleep

A
  • acute = short term
  • chronic = long term
  • more common model (partial sleep deprivation/restricted sleep)
6
Q

sleep fragmentation

A
  • going to sleep at the usual time but sleep is disrupted throughout the night
  • may end up spending more time in the lighter stages of sleep/less time in deep sleep
7
Q

sleep deprivation: cognitive function

A

Van Dongen et al (2003)

  • used a range of deprivation periods (TSD, 4, 6, 8h sleep)
  • assessed a range of cognitive tasks (attention, sleepiness, addiction, subtraction)
  • attention (psychomotor vigilance test) = TSD resulted in longer reaction times. the more sleep they had the better their performance
  • addition/subtraction (serial addition/subtraction task & digit symbol substitution task) = same pattern as above
  • sleepiness (objective measure) = TSD say they feel tired, but those who were PSD do not say they are tired yet still perform worse than the 8h condition
  • sleepiness scale doesn’t correlate to cognitive measures - individuals are not very good at knowing when they are tired
  • cant say its down to the task that people are performing differently as there are multiple
8
Q

sleep deprivation: architecture

A

Van Dongen et al (2003) - 4, 6 or 8h sleep
- stage 1 = very little different found
- stage 2 = restricted sleep (4h) spend less time here
- stage 3 and 4 = very little difference here (shows how important this stage is as when sleep deprived individuals don’t sacrifice sleep here)
REM = those restricted to 4 and 6h sleep have signficiant reductions in REM sleep

4h = lowest Delta activity, reducing to 60% or the normal rates at one stage

9
Q

sleep deprivation: emotional wellbeing

A

Yoo et al (2007) - 18-30 year olds (N = 26) assigned to sleep deprivation (awake for 35h) or control conditions

  • emotional stimulus task was performed whilst an fMRI was recording the small changes in blood flow of the brain
  • 100 images ranging from positive to negative (spectrum)
  • the sleep deprived group showed 60% more amygdala activation to negative stimuli (more sensitive to negative events)
  • amygdala is influences by the medial prefrontal cortex (MPFC) - inhibitory top down control of amygdala (acts as a break) - seems to be disconnect here
10
Q

sleep deprivation: weight management

A

Van Cauter et al., (2005)

  • good sleep helps keep appetite in check, stop cravings and reduce late night eating. it can determine how easy or hard it is to lose weight
  • two types of hormones that are involved in regular hunger and appetite, important for regulating metabolism also:
    1. Ghrelin (increases hunger)
    2. Leptin (suppresses hunger)
  • can change our appetite but also our choice of food
  • when you are sleep deprived Ghrelin increases appetite for calorie rich food, leading to poor choices
  • when you are sleep deprived, the production of leptin is suppressed (even short term deprivation)
  • linked to obesity and public health
  • even if you eat healthy but are are also sleep deprived, the body retains energy (fat) as it is low on energy (sleep)
11
Q

sleep deprivation: immune system

A
  • same impact as stress, weakens the ability to defend against infection and viruses
  • sleep deprivation reduces the amount of natural killer cells that help fight against illness, infections and viruses
12
Q

sleep deprivation: neurodegeneration

A

lack of sleep leads to a build up of a toxis chemical called beta amyloid (which is associated with the development of Alzheimer’s)

  • SWS associated with removal of these chemicals
  • less SWS = more beta amyloid = higher risk of dementia
13
Q

sleep deprivation vs alcohol consumption

A

Dawson and Reid (1997)

  • participants where either kept awake for 24h or recieved 10-15g of alcohol at 30 min intervals until their mean blood alcohol level was .1%
  • cognitive psychomotor ability assessed using hand eye coordination test delivered on a computer
  • the longer you are awake, the worse the performance
  • similar to the performance you see when drinking alcohol
  • think drink driving
14
Q

methodological limitations

A
  • don’t take napping into account, how would you control?
  • practice effects = tasks associated with cognitive function can be performed better by some individuals compared to others
  • divergence between subjective and objective measures = people aren’t good at knowing how tired they are so subjective measure may be impacted
  • differences in paradigms used makes it hard for comparison = partially sleep deprived > time, amount, location of sleep
  • individual differences = everybody’s sleep needs are different, you can have morning/evening types, could have consumed caffeine or get affected by it differently, age)