Sleep – the most common ASC

1. Sleep – the most common ASC

2. Studying Sleep • Polysomnography- detailed monitoring and recording of physiological responses during sleep • Heart rate and body temperature • Video monitoring • Self-report

3. Studying Sleep • Electroencephalogram – EEG Detects, amplifies, records electrical activity of the brain • Electromyograph– EMG Detects, amplifies, records electrical activity of the muscles • Electro-oculargram– EOG Detects, amplifies, records electrical activity of eye movements

4. The sleep Scientist at Work

5. Sleep patterns and stages

6. Non Rapid Eye Movement sleep • Stage 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

7. Non Rapid Eye Movement Sleep • Stage 3 NREM – deeper sleep, more slowing of bodily function (theta, delta) 30 mins • Stage 4 NREM – Deepest, hard to wake, disorientated (delta) 20 mins at beginning less as night goes on

8. Rapid Eye Movement Sleep • REM 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

9. 1 = Alpha/Theta 2 = Theta/Spindles/ K complex 3 = Theta / Delta 4 = Delta REM = Alpha

10. Work sheet • Sleep phenomena: walking and terrors http://www.youtube.com/watch?v=4Vh56g9b92U&feature=related • How is a night terror different from a night mare? • What stage of sleep to sleep phenomena such as sleep walking and sleep terrors occur? • REM behavioural disorder • http://www.msnbc.msn.com/id/29658353/ns/dateline_nbc-crime_reports/

11. Sleep pattern shifts over the lifespan • Most people your age get about 8 hours • Research shows that adolescents need 9 or 10 hours • Many 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

12. 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

13. Why do we need to sleep? • Restoration • Recovery from physical and mental exertion • Repair damaged cells • Replenish energy stores • Memory formation • Survival • Night time is dangerous for humans • Being inactive during this time aids our survival as we are less likely to be eaten!

14. Sleep Deprivation • Means going without sleep • Involves partial or total loss of sleep • May 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

15. 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

16. Physiological effects • Heart slows, shaking, increase sensitivity to pain, immune function impaired • Effects can be overcome with a few good nights sleep with fewer hours sleep than those lost

17. Sleep deprivation research – do sleeping pills work? • Research using the administration of drugs often encounters a problem known as the Placebo effect • The 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