Sleep – the most common ASCYay sleep, that’s where I’m a viking!

Studying SleepSleep LabsPolysomnography - detailed monitoring and

recording of physiological responses during sleep

Studying SleepElectroencephalogram - EEGElectromyograph - EMGElectro-oculargram - EOG

The sleep Scientist at Work

Sleep patterns and stages

Non Rapid Eye Movement sleepStage 1 NREM – dosing, falling asleep, hypnic jerks, losing

awareness (alpha, theta) 5 – 10 mins

Stage 2 NREM – truly asleep, everything continues to slow, (theta with spindles – high frequency & k complexes - low freq high amplitude) may still think not asleep 10 – 20 mins

Non Rapid Eye Movement Sleep3 NREM – deeper sleep, more slowing of bodily function

(theta, delta) 30 mins

4 NREM – Deepest, hard to wake, disorientated (delta) 20 mins at beginning less as night goes on

Rapid Eye Movement SleepREM sleep – Rapid eye movement, dream

sleep Higher arousal but not awake,Helps consolidate memories - form new

connections between neurons, evidence that young have more REM than old as brain still developing

1 = Alpha/Theta

2 = Theta/Spindles/ K complex

3 = Theta / Delta

4 = Delta

REM = Alpha

Sleep pattern shifts over the lifespanMost people your age get about 8 hoursResearch shows that adolescents need 9 or

10 hoursMany people report not being able to get to

sleep quickly, not getting enough sleep and difficulty getting up in the morning

Biological factors – rhythms – regulate when we sleep and wake through the release of hormones that make us tired

Our sleep-wake cycle is called a circadian rhythm – this means about a day

So why are you tired?During adolescence your sleep-wake cycle is shifted

biologically (through the release of hormones) to make you require about 2 hours more sleep!

But our school and work day does not really allow for this! (that’s shit)

As we consistently get less than optimum sleep we create a sleep debt – this compounds like a fine you haven't payed – it gets bigger and bigger

As a result you try to catch up on the weekend! But then you go to bed later and compound the problem!

Research shows that less than 8 hours has a negative impact on cognitive function

Why do we need to sleep?Restoration 1. Recovery from physical and mental exertion2. Repair damaged cells3. Replenish energy stores4. Memory formation

Survival1. Night time is dangerous for humans2. Being inactive during this time aids our

survival as we are less likely to be eaten!

Sleep DeprivationMeans going without sleepInvolves partial or total loss of sleepMay occur during one night or for several

nights.Varies from one individual to another

Longest anyone known to have gone without sleep is 11 days – suffered severe psychological effects during deprivation, hallucinated and deluded

Psychological effects

Results in unpleasant feelings, irritability, fatigue, loss of concentration, headaches, lowered energy levels and slower reaction time

Extreme cases depression, hallucinations & delusions. Effects can be overcome with a few good nights sleep with fewer hours sleep

than those lost

Physiological effectsHeart slows, shaking, increase sensitivity to

pain, immune function impairedEffects can be overcome with a few good

nights sleep with fewer hours sleep than those lost

Sleep deprivation research – do sleeping pills work?Research using the administration of drugs often

encounters a problem known as the Placebo effectThe placebo effect occurs when a participant's

behavioural response is influenced by their expectation of how they should behave

The expectations of the participants rather than (or as well as) the independent variable, may be affecting the dependent variable and therefore the results

Eg. You know you had the drug so you expect to sleep better. I cant know now if the drug or your expectation caused the change