Polysomnography - methods of measuring sleep
Electroencephalogram (EEG)
- brain waves
Electrooculogram (EOG)
- eye movements
Electromyogram (EMG)
- muscle tension
Polysomnography - methods of measuring sleep
Electroencephalogram (EEG)
- brain waves
Electrooculogram (EOG)
- eye movements
Electromyogram (EMG)
- muscle tension
stages of sleep
Wake
- alert
- relaxed eyes closed
Stage 1 - drifting
Stage 2 - brain blocks stimulus from outside world
- napping
Slow wave sleep - deepest sleep
REM - rapid eye movement
- resemble waking activities
during REM sleep
- pons sends signal up to brain to dream
- pons sends signal down to spine to tell muscles to stop moving
- causes sleep paralysis when not disabled when you wake up
sleep as homeostatic
the more you’re awake the more you need to sleep
sleep load
sleep as circadian
body clock
zietgeber
the external/environmental cue that entrains or synchronises our biological rhythms/ circadian rhythms
Light is our primary influence of zeitgeber, associating the day/night with awake and sleep
what happens when you get jet lag?
- occurs when crossing large number of time zones quickly
- results of a mismatch between our internal cock and our external day
- demonstrates the importance of circadian rhythm for alertness levels and sleep propensity
- generally worst traveling east (with the rotation of the earth)
stages of sleep
Wake
- alert
- relaxed eyes closed
Stage 1 - drifting
Stage 2 - brain blocks stimulus from outside world
- napping
Slow wave sleep
- deepest sleep
- stage 3 - delta waves appear
- stage 4 - mostly delta waves
REM - rapid eye movement
- resemble waking activities
during REM sleep
- pons sends signal up to brain to dream
- pons sends signal down to spine to tell muscles to stop moving
- causes sleep paralysis when not disabled when you wake up
sleep as homeostatic
the more you’re awake the more you need to sleep
sleep load
sleep as circadian
body clock
circadian rhythm
behavioural , biochemical and physiological fluctuations occurring over a 24 hour period
- Sleep/wake cycle influenced by internal clock j
- out internal clock is generally longer than 24 hours
- suprachiasmatic Nucleus (SCN)
Light is our primary …
zietgeber
what happens when we don’t sleep?
Sleep deprivation can lead to…
- increased likelihood to sleep
- slowed response times
- narrowing of attention
- microsleeps
- lapses and errors in many cognitive and practical tasks
-
what happens when we don’t sleep?
Chronic sleep restriction
- gradually building up “sleep debt”
- overtime, the effect is similar to sleep deprivation
- mood
- task performance
- recovery is not immediate
Sleep and Memory
actively integrating new memories with pre-existing knowledge
- sleep following declarative task learning improves retention
- slows forgetting the info
- memory is more resistant to interference
- sleep can lead to insight into previously learned info
- slow wave sleep is particularly important in memory retention
how much sleep do we need
individual differences with no way to test for a specific number of hours
evidence suggest we are generally under-slept
duration is not the only factor if adequate sleep
characteristics of sleep
satisfaction
alertness
timing
efficiency
duration
‘Good’ sleep categorised by…
~7-9- hours
consolidated sleep - no interruptions
subjective night (circadian dips into allertness)
regular wake/sleep times
variation is normal
problems with sleep
insomnia
sleep related breathing disorders
central disorders of hyper somnolence
circadian rhythm disorders
parasomnia
sleep related movement disorders
problems with sleep
insomnia
can be considered a symptom or disorder
defined -
difficult to initiate or maintain sleep OR poor quality of sleep at least once a month
treatment with psychological and behavioural strategies
- eg restriction of time in bed, sleep hygiene education
sleep state misperception
hyper arousal
