1. Sleep Deprivation. (aka ‘a teacher’s life’) L
Sleep Deprivation! (aka ‘a teacher’s life’) L.O - Explain the term ‘sleep deprivation’ and the effects of total and partial sleep deprivation - Describe and evaluate research relating to sleep deprivation (e.g. Randy Garner and Peter Tripp).
Plenary -
Dement and Kleitman -
Secrets of Sleep: Peter Tripp -

2. What happens if we don’t sleep?

3. The February 9, 1959 issue of LIFE magazine published a photo feature on WMGM New York deejay Peter Tripp. He had just completed a 201 hour marathon on behalf of the March of Dimes. At right, he is joined by his wife 199 hours and 50 minutes into the epic effort.
Tripp was attended throughout by medical professionals, who cautioned others DJs not to try such stunts because of the dangers. Tripp experienced hallucinations and symptoms of mental illness as the marathon wore on, picking imaginary bugs from his clothing and looking for cash in an empty drawer.

4. Sleep Functions L.O Outline & Evaluate the Restoration Theory of sleep’s function
Plenary -
Dement and Kleitman -
Secrets of Sleep: Peter Tripp -

5. Restoration theories Theories of Sleep
“Every stage of sleep is essential for restoration!”
“No! Only
SWS4 and REM are essential for restoration!”
Oswald
(1966)
Horne
(1988)
‘Core sleep’ = SWS4 + REM:
essential for repair/restoration of the brain
2. ‘Optional sleep’ = SWS1-3: not needed at all for repair/restoration
Restoration of the body happens
when we are awake and relaxed
SWS3-4 are all needed: for repair/restoration of the body
REM is essential: for repair/restoration of the brain

6. lack of restoration of the brain?
Theories of Sleep
Which of these effects
could be attributed to
lack of restoration of the brain?
lack of restoration of the body?

7. Increase in REM sleep during brain growth, reorganiation and repair?

8. FUNCTION OF SLEEP
RESTORATION THEORY

9. OSWALD (1969)
Found in patients with damage to their CNS (spinal cord/brain) and patients who have taken an overdose (that may have damaged the brain) that they engaged in more REM sleep than normal subjects.

10. According the RESTORATION THEORY, what is the function of SLEEP?
2) What is REM sleep for?
What is SWS for?

11. This theory suggests that RESTORATION TO THE BODY, from damage caused during the day, OCCURS DURING SLEEP.

12. It was suggested that;
REM SLEEP – the brain restores itself
SLOW WAVE SLEEP (stages 3 and 4) – the body restores itself.

13. 5 MINUTES
3) How does the sleep of NEWBORN BABIES support the theory that REM sleep is for GROWTH OF BRAIN TISSUE?

14. Newborn Babies They show 50% more REM sleep than adults
Newborn Babies They show 50% more REM sleep than adults. It is theorised that because the brain grows at such a rate during this stage, REM sleep is required for growth.

15. 4) What effect does sleep have on our levels of NEUROTRANSMITTERS?
5 MINUTES
4) What effect does sleep have on our levels of NEUROTRANSMITTERS?

16. Adults - REM
It is also suggested that sleep is an important way of replenishing NEUROTRANSMITTERS (NTs).
NTs are CHEMICAL MESSENGERS which carry ELECTRICAL SIGNALS from neuron to neuron. They are important to keep us alert and for our brain to function.
As we go through the day, the amount of NTs in our brain DECREASES.
REM Sleep replenishes NTs for use during wakefulness

17. Oswald (1969) – 5 MINUTES
5) What does OSWALD state happens during SLOW WAVE SLEEP (stages 3 and 4)?

18. SLOW WAVE SLEEP
It is hypothesised this is necessary for RESTORATION of the BODY. During this stage of sleep GROWTH HORMONE is released. This stimulates PROTEIN SYNTHESIS i.e. Production of new body tissue.

19. HORNE (1988) – 10 MINUTES
6) What did HORNE label SWS and REM sleep? Why does Horne state this sleep is important? What does HORNE label stages 1 and 3 of sleep?

20. HORNE (1988)
Horne (1988) labelled SLOW WAVE SLEEP (SWS) and REM as ‘CORE SLEEP.’
He stated that during this stage, brain repairs for vital functioning.
Horne (1998) labelled NREM sleep as ‘OPTIONAL SLEEP’.
He believed that the restoration that takes place during optional sleep can occur just as readily in WAKEFUL REST.

21. Oswald 1966
Horne 1988
Core Sleep
REM
Stage 1-4
Optional sleep
Stage 1-3
Stage 4 + REM
Child hormones
Adults proteins
Chemical Neurotransmitter
Bodily repair
Brain repair

22. The definitive explanation of why we need to sleep is unclear, however, one theory of sleep is the restoration theory. It was proposed by Oswald in He believed that the REM part of sleep was needed for the brain to recover from the days work and therefore explains why the brain is active, as it is repairing itself. During this time key chemicals called neurotransmitters are produced. During slow wave sleep, stages 1-4 the body is going through repair. In young people large amounts of hormones are produced and in adults proteins are produced which are known to repair cell damage.
The restoration theory was further developed by Horne in 1988 who believed that not all sleep was necessary. He said core sleep, particularly REM sleep and stage 4, was needed for repair and restoration but that stages 1-3 were ‘optional’ sleep. The main purpose of this optional sleep is to conserve energy. This idea of conserving energy links into the second theory proposed by psychologist such as Meddis and Webb.

23. Neurotransmitters restored
Jouvert 1967
Cats placed on islands of flower pots floating in water. They could balance on the pot and enter stages 1-4 sleep but in REM muscles would relax and cat would fall into the water and wake up. So REM deprived. The cats became disturbed and died after about 35 days
Horne 1988
Amino acids which form proteins come from our food. Therefore if amino acids are to make protein during SWS we would need to go to bed within five hours of eating as this is how long they remain in the body! We don’t usually manage this though!
Shapiro et al 1981
Runners sleep patterns were studied and found that those runners in a marathon slept for an extra hour on 2 nights following a race. It was their SWS which increased. Compared to non race days sleep.
Neurotransmitters restored
REM requires a lot of neural activity of the brain. How could this restore neurotransmitters? Surly it would in fact use them up!
Newborn babies spend up to 18 hours asleep
Randy Gardener/ Peter Tripp

24. Randy Gardener/ Peter Tripp
Supports the restoration theory by Oswald as more cell growth in new born babies compared to adults who sleep less.
Horne 1988
Amino acids which form proteins come from our food. Therefore if amino acids are to make protein during SWS we would need to go to bed within five hours of eating as this is how long they remain in the body! We don’t usually manage this though!
Newborn babies spend up to 18 hours asleep
Jouvert 1967
Cats placed on islands of flower pots floating in water. They could balance on the pot and enter stages 1-4 sleep but in REM muscles would relax and cat would fall into the water and wake up. So REM deprived. The cats became disturbed and died after about 35 days
Neurotransmitters restored
REM requires a lot of neural activity of the brain. How could this restore neurotransmitters? Surly it would in fact use them up!
This goes against the restoration theory of sleep
Goes against Oswald theory of SWS being necessary for protein synthesis as the amino acids from food are no longer available to be made into protein when we sleep. This must happen when we are awake
Supports restoration theory Horne as it shows that REM sleep is the sleep needed for survival not stages 1-4. Does not explain why though.
Randy Gardener/ Peter Tripp
Support Restoration theory as when the participants went to sleep they had REM rebound. They did not make up the lost sleep of stages 1-4 suggesting that REM is the restorative part of sleep.
Shapiro et al 1981
Runners sleep patterns were studied and found that those runners in a marathon slept for an extra hour on 2 nights following a race. It was their SWS which increased. Compared to non race days sleep.
This supports Oswald restoration theory as the more damage we do to our bodies during the day the more ‘restoration’ or repair is needed at night which takes place in stages 1-4.

25. SUPPORT OF THEORY SWS increased – SUPPORT OR CONTRADICT THEORY?
Shapiro et al (1981): Researcher marathon runners – slept for about an hour more for TWO NIGHTS.
SWS increased – SUPPORT OR CONTRADICT THEORY?
Horne and Minard (1985): put participants through exhausting tasks – went to sleep quicker but did not sleep for longer.
SUPPORT OR CONTRADICT THEORY?

26. ISSUES
Theory says NTs are replenished.  Think about what you know about brain activity during sleep, especially REM. Would this be the case?
Horne (1988): AMINO ACIDS (what make up proteins) are only available for 5 hours after a meal.  SO, do you think PROTEIN SYNTHESIS (making proteins) would be possible during sleep?

27. Describe and evaluate two theories of the function of sleep 24 (marks)
What detail would we expect to see for 8 marks?
Concise, 2 theories, all parts explained in brief detail. Terminology will be expected and technical detail.

29. Sleep Functions L.O Outline & Evaluate the Ecological / Evolutionary Theory of sleep’s function
Plenary -
Dement and Kleitman -
Secrets of Sleep: Peter Tripp -

30. Ecological theories Webb Meddis (1982) (1975)
Theories of Sleep
Ecological theories
‘PROTECTION THEORY’
Sleep is an adaptive behaviour TO KEEP US SAFE FROM DANGER
‘HIBERNATION THEORY’
Sleep is an adaptive behaviour TO CONSERVE ENERGY
Webb
(1982)
Meddis
(1975)
Sleep is like hibernation.
During hibernation/sleep, body temp falls and the animal is inactive
Therefore less energy is used – at a time when food is scarce or it is dangerous to go out looking for food
[Humans still sleep due to ‘evolutionary hangover’]
Night was a time of danger for our ancestors (falls, predators with better night sight…)
So couldn’t safely forage at night
Sleep gave an adaptive advantage by keeping us out of harm’s way
Prey are (usually) small  high metabolism  sleep more to conserve energy?

32. Predator avoidance (?)
Sleep constrained/limited by risk of predation
If an animal is a predator it can sleep for longer
Prey species’ sleep time is reduced because animal must remain vigilant to avoid predators
Logically then, to be safe the animal shouldn’t sleep at all! BUT sleep has a vital function, so instead, if they can, animals can sleep to hide

33. Hiding from predators (waste of time)
MEDDIS sleep helps animals stay out of the way of predators during parts of the day when they are most vulnerable, normally in hours of darkness, where they will be hidden. Sleep may ensure the animals stay still when they have nothing better to do with the time
SIEGEL (2008)- concurs with this view and claims that being awake is more dangerous than sleeping because an animal is more likely to be injured
YOUNG the best strategy for passing on our genes is to be asleep in a safe place for as long as possible
Little brown bat – awake for a few hours each day, when the insects it feeds on are awake!

34. Energy conservation
Endotherms (warm blooded animals) such as mammals, expend a lot of energy maintaining a constant body temperature
ESPECIALLY problematic for small animals with high metabolic rates
Sleep provides a period of inactivity
WEBB described this as the hibernation theory of sleep

35. Foraging requirements
Time spent sleeping may be constrained/limited by food requirements
Herbivores eat plants- which are relatively poor in nutrients; SO spend more time eating- less time available for sleep
Carnivores eat meat- high in nutrients; SO don’t need to eat constantly- more time for sleep

37. Foraging requirements
ECOLOGICAL PRESSURES
RELEVANT FEATURES OF AN ANIMAL (& HABITAT)
RELEVANT RESEARCH / FINDINGS
IMPLICATIONS / ISSUES
Energy conservation
Foraging requirements
Predator avoidance / Waste of time

38. More factors to consider
What is the relationship between amount (& structure) of sleep and ...
Body Mass
Brain Mass
Base Metabolic Rate
Position on the food chain
Security of sleep location!
For each, WHY?? And –in real life- HOW would they interact?

39. Structure of sleep (REM / NREM)
ECOLOGICAL PRESSURES
Study
Amount of Sleep
Structure of sleep (REM / NREM)
IMPLICATIONS / ISSUES
Body Mass
Brain Mass
Base Metabolic Rate
Position on the food chain
Security of sleep location

40. Describe and evaluate two theories of the function of sleep (24 marks)
What detail would we expect to see for 8 marks?
Concise, 2 theories, all parts explained in brief detail. Terminology will be expected and technical detail.

41. Zepelin and Rechtschaffen 1974. Meddis, Pearson and Lanford 1973
53 species of mammals studied. Found that animals with a higher metabolic rate tended to sleep for longer. Smaller animals sleep for longer e.g. a brown bat sleeps for 20 hours per day compared to an elephant which sleeps for only 4 hours.
Meddis, Pearson and Lanford 1973
Some humans can function perfectly well on very little sleep. One participant a 70 year old cheerful retired female nurse slept for only 1 hour per night. She would read or write until 2 in the morning then sleep for one hour. When studied under lab conditions she slept on average for 67 minutes per night.
A sloth sleeps for 20 hours but is large and has slow metabolism!
Horne 2001
There is very little difference in energy conserved when we are asleep to when we are awake but resting!
Rechtschaffen 1989
Rats on a turn table. When ever their brain patterns changed to show they were sleeping the turn table started to turn so that they woke up and exercised. If they didn’t they would fall into water. The rat only had 16 % of its usual sleep. The rat was weak and lost weight even though it still ate as its metabolic rate had increased. Most of the experimental rats died between days after the experiment began.
Pilleri 1979
One particular type of dolphin sleeps for only a few seconds at a time as they are in constant danger of floating debris injuring them.

42. Zepelin and Rechtschaffen 1974. Meddis, Pearson and Lanford 1973
53 species of mammals studied. Found that animals with a higher metabolic rate tended to sleep for longer. Smaller animals sleep for longer e.g. a brown bat sleeps for 20 hours per day compared to an elephant which sleeps for only 4 hours.
A sloth sleeps for 20 hours but is large and has slow metabolism!
Meddis, Pearson and Lanford 1973
Some humans can function perfectly well on very little sleep. One participant a 70 year old cheerful retired female nurse slept for only 1 hour per night. She would read or write until 2 in the morning then sleep for one hour. When studied under lab conditions she slept on average for 67 minutes per night.
Goes against ecological theory as sloth should sleep very little as its energy consumption is low throughout the day (since it’s a large animal)
Horne 2001
There is very little difference in energy conserved when we are asleep to when we are awake but resting!
This supports the Energy conservation part of the ecological prospective proposed by Webb
Rechtschaffen 1989
Rats on a turn table. When ever their brain patterns changed to show they were sleeping the turn table started to turn so that they woke up and exercised. If they didn’t they would fall into water. The rat only had 16 % of its usual sleep. The rat was weak and lost weight even though it still ate as its metabolic rate had increased. Most of the experimental rats died between days after the experiment began.
Goes against ecological theory as suggest that sleep does not conserve energy.
Pilleri 1979
One particular type of dolphin sleeps for only a few seconds at a time as they are in constant danger of floating debris injuring them.
Supports ecological theory in that some humans have adapted to sleep less if they have less need to conserve energy
Supports ecological account as rats died because their metabolic rate was high they needed to rest to conserve energy.
Supports Ecological theory of sleep predator avoidance: animal sleeps less as it is in more danger.

43. Zepelin and Rechtschaffen 1974. Meddis, Pearson and Lanford 1973
53 species of mammals studied. Found that animals with a higher metabolic rate tended to sleep for longer. Smaller animals sleep for longer e.g. a brown bat sleeps for 20 hours per day compared to an elephant which sleeps for only 4 hours.
A sloth sleeps for 20 hours but is large and has slow metabolism!
Meddis, Pearson and Lanford 1973
Some humans can function perfectly well on very little sleep. One participant a 70 year old cheerful retired female nurse slept for only 1 hour per night. She would read or write until 2 in the morning then sleep for one hour. When studied under lab conditions she slept on average for 67 minutes per night.
Goes against ecological theory as sloth should sleep very little as its energy consumption is low throughout the day (since it’s a large animal)
Horne 2001
There is very little difference in energy conserved when we are asleep to when we are awake but resting!
This supports the Energy conservation part of the ecological prospective proposed by Webb
Rechtschaffen 1989
Rats on a turn table. When ever their brain patterns changed to show they were sleeping the turn table started to turn so that they woke up and exercised. If they didn’t they would fall into water. The rat only had 16 % of its usual sleep. The rat was weak and lost weight even though it still ate as its metabolic rate had increased. Most of the experimental rats died between days after the experiment began.
Goes against ecological theory as suggest that sleep does not conserve energy.
Pilleri 1979
One particular type of dolphin sleeps for only a few seconds at a time as they are in constant danger of floating debris injuring them.
Supports ecological theory in that some humans have adapted to sleep less if they have less need to conserve energy
Supports ecological account as rats died because their metabolic rate was high they needed to rest to conserve energy.
Supports Ecological theory of sleep predator avoidance: animal sleeps less as it is in more danger.

44. Evaluation of the Meddis ‘Protection Theory’
Appreciates complexity of relationship between sleeping, predator-prey relationships, and body size (+ve)
Theory predicts prey animals should sleep longest, to keep safe from predators – not always true. Horses sleep little, lions sleep a lot (-ve)
Sleep isn’t just about protection and body size - involve food requirements as well (herbivores such as horses eat very poor quality food, so have to stay awake long enough to eat enough; carnivores such as lions eat very high quality food, so don’t have to spend lots of time feeding and can afford the time to sleep) (-ve)
Other animals more vulnerable sleeping. E.g. Indus dolphin in danger of being hit by debris in river, so why not evolve sleeplessness? Perhaps the theory misses something about why sleep is essential for life. (-ve)

45. Evaluation of the Webb ‘Hibernation Theory’
Seems logical; certainly true for hibernating animals, who have to use as little energy as possible while asleep for long periods of time - perhaps over a period of several months - to survive harsh environmental conditions (+ve)
But simply sleeping overnight saves very little energy for humans - we wouldn’t starve if we didn’t sleep for a night. Just being inactive while staying awake, would save almost as much energy as sleeping (the equivalent of the energy content of a slice of bread) (-ve)
This seems to be a simplistic theory, only taking into account food and energy conservation. (-ve)

46. Evolutionary Theory – General Evaluation
Theories of Sleep
Evolutionary Theory – General Evaluation
Empson (1993) criticised ecological/evolutionary theories as ‘a waste of time’. For instance, they don’t explain:
- why we have five stages of sleep
- why lab animals die when deprived of sleep
- why we suffer psychological problems when deprived
of sleep
Maybe sleep is simply vital for survival - perhaps leading us to the idea of restoration theories. (-ve)

47. Evolutionary Theory – General Evaluation
Theories of Sleep
Evolutionary Theory – General Evaluation
2. Why do humans still sleep, when we have artificial lighting and few or no predators? Can criticise this criticism by suggesting that it takes a long time for non-harmful characteristics to evolve out of a species, and even if it’s pointless now, sleep isn’t damaging to us.
But alternatively, sleep could be essential for other reasons, so again we need to consider theories which suggest sleep is needed for restoration of body and/or brain. (-ve)

48. IDAs
You will need to include in an evaluation of issues/ debates and approaches
Can you give 2 evaluation points in good detail?

49. Another way to think about PEE is..
State -Many evolutionary explanations theories are not scientific.
Explain – Evolutionary theories of sleep are speculative, in that they do not have controlled evidence to back up their claims.
Apply – By not having evidence to support your theory, you cannot claim that the approach is ‘scientific’. As we cannot access sleep patterns from our evolutionary past, how can we use evolution to explain the behaviour now?

53. IDA application Determinism Determinism
Evolutionary theories are seen to be deterministic as they ignore free will. Humans now use external cues to choose then they get up with alarm clocks.
Work/school patterns require us to control how long/when we sleep. The evolutionary explanation of sleep cannot account for these factors.

54. Reductionism Reductionism
“This theory is also reductionist. Sleep is a complex subject but for this theory has been explained through evolutionary pressure alone. It does not explain why there are different stages and cycles of sleep – these must happen for a reason.
Furthermore, it does not attempt to explain why if we miss sleep we then need to catch up on it. If it was down to protection alone, missing sleep would not matter as long as we had survived. Therefore, physiological and psychological functions of sleep are ignored, resulting in a theory that does not fully explain sleep.”