1. AS Psychology

2. AS level Psychology The Core studies
The Biological Approach

3. What are the strengths and weaknesses of the physiological approach?

4. Assumptions
The assumptions of the physiological approach are that our biology has a significant impact on our behaviour.
Some physiological psychologists would say that our brain and nervous system determine most of our behaviour.
They study the brain, the nervous system, the endocrine system (hormones such as adrenaline, testosterone and oestrogen etc), heredity and disease, to determine their effects.
In terms of the nature v nurture debate they consider nature to be most important.

5. Assumptions
In the past studies have often been carried out on animals or on identical twins.
However the onset of EEG machines to measure brainwaves and MRI scanning together with genetic engineering has recently extended our understanding of the human brain and how it works.
The physiological approach also includes the work of evolutionary psychologists who study instinctive behaviours which are common to all animals and determine the reproduction of their species.

6. Evaluation of the approach…
There are considerable strengths to the physiological approach as many tests which can be carried out such as EEG’s, MRI’s and DNA testing are highly scientific and therefore reliable.
We all have very similar biological brains and nervous systems so data is also highly generalisable.
However brain imaging techniques are relatively new and we cannot always be sure we are interpreting them correctly.

7. Evaluation of the approach…
We may see changes in brain functions but these techniques do not tell us what is causing those changes.
Otherwise we often have to rely on the self report method when studying the brain and so demand characteristics may be a problem.
Studies which are carried out in laboratories or hospital settings could also be said to lack ecological validity.

8. Dement & Kleitman (1957)
The relation of eye movements during sleep to dream activity…
What can you remember so far?

9. Dement & Kleitman (1957) Why do we sleep?
Theories of the function of sleep:
With a partner mind map why we sleep…

10. Restoration Theory (the body repairs damaged tissues and cells during sleep)

11. Memory Consolidation Theory (Storage of new memories, linked to hippocampus)

12. Evolutionary Theory (Sleep is linked to evolution, a tool used to create energy)

13. Why do we sleep?

14. REM: Rapid Eye Movement
Occupies 20-25% of total sleep,
Muscles relaxed
minutes of a night's sleep.
Usually experience 4 or 5 periods of REM sleep

15. NREM: Non-Rapid Eye Movement, (little or no eye movement)
Dreams do not usually take place in this stage.
Muscles are more toned

16. What is deep sleep?
How do you measure sleep?
What issues would you see doing this?

17. EEG (Electroencephalography): A test that measures and records the electrical activity of your brain.

18. EOG (Electrooculography): eye movements

19. EMG: shows muscle activity

20. Dement & Kleitman (1957) Measuring Sleep

21. Most dreaming occurs during REM sleep.
When woke in REM sleep people can say what they were just dreaming.
The EEG pattern during REM, similar to EEG pattern when awake.
Muscle activity is very quiet during REM sleep.
Muscles are inactive to prevent us from acting out our dreams.
Sleepwalkers are not in REM sleep

23. Sleep and Dream states Consciousness
Consciousness, goes on between your ears when you are awake
DREAMING is a state of consciousness (altered state of consciousness, sleep, drugs, meditation, hypnosis)
What did you last dream about: write it down does it make sense????

24. Sleep and wakefulness Seem different but have a lot in common In sleep
we may ‘talk’
we may ‘walk’
we have memories
we can even plan things
According to biographers of McCartney and the Beatles, McCartney composed the entire melody of ‘Yesterday’ in a dream one night in his room. Upon waking, he hurried to a piano and played the tune to avoid forgetting it.

25. Sleep and dream states we spend 30% of our lives asleep
sleep is an active NOT a passive behaviour

26. What would happen if we didn't’t sleep?

27. The evolutionary theory
all species sleep, thus sleep MUST have a valuable function (survival of the species)
Do animals need sleep?
Rats deprived of sleep die after 21 days

28. Human sleep deprivation?
REM sleep seems important:
The Randy Gardner study
volunteers who are gradually deprived of sleep
(sleep reduced from 8 hours to 2 hours)
pack REM sleep into the time they CAN sleep

29. Human sleep deprivation?
John Schlapobersky, consultant psychotherapist to the Medical Foundation for Victims of Torture, was himself tortured through sleep deprivation, in his case in apartheid South Africa in the 1960s.

30. John Schlapobersky
"I was kept without sleep for a week in all. I can remember the details of the experience, although it took place 35 years ago. After two nights without sleep, the hallucinations start, and after three nights, people are having dreams while fairly awake, which is a form of psychosis.

31. John Schlapobersky
"By the week's end, people lose their orientation in place and time - the people you're speaking to become people from your past; a window might become a view of the sea seen in your younger days. To deprive someone of sleep is to tamper with their equilibrium and their sanity."

32. 5 stages of sleep

33. The stages of sleep Before sleep: Synchronised alpha waves
heart rate slows, temperature falls
muscle tension reduces

34. ALPHA
AWAKE
BETA
THETA
THETA K-Spindles
DELTA
DELTA

35. Brainwaves
Beta - Emitted when we are consciously alert, or we feel agitated, tense, afraid,
Alpha - When we are in a state of physical and mental relaxation, although aware of what is happening around us.
Theta – A state of reduced consciousness.
Delta - When there is unconsciousness, deep sleep.

38. The stages of sleep Stage 1 sleep - alpha waves reduced
less desynchronised brain activity
Stage 2 sleep - synchronised brain activity
larger and slower waves
bursts of sharp ‘spikes’
(sleep spindles)

39. The stages of sleep Stage 3 sleep - slow delta waves
less sleep spindles
heart and breathing rate continue to fall
Stage 4 sleep - only delta waves
arousal threshold high (people are hard to wake up)
4 stages of Slow Wave Sleep

40. Stage 5 - REM sleep REM sleep –
after 90 minutes EEG shows SHIFT into fast desynchronised brain activity
Beta Waves
heart rate increases
skeletal muscles relaxed (paralysis)
Rapid Eye Movements occur (REM)

41. Dement and Kleitman
Developed a rigorous and objective test of the relationship between REM sleep and dreaming

42. A sleep laboratory volunteer

43. Dement and Kleitman Three ways to collect data: First DV
Dream recall during REM and NREM sleep
they woke people up and asked them if they had dreamed

44. Dement and Kleitman Three ways to collect data: 2nd DV
Asked participants to say how long their dreams had lasted

45. Dement and Kleitman Three ways to collect data:
3rd DV- patterns of eye movements were related to the reported dream content
to test whether the movement represented specific expression of the visual dream experience

46. Dement and Kleitman Third DV - the criteria FOUR eye movement patterns
1 mainly vertical
2 mainly horizontal
3 vertical & horizontal
4 little or none

47. Dement and Kleitman 9 participants (7 male & 2 female)
only 5 studied intensively
method - a lab experiment
The procedure - Ps asked to refrain from alcohol & caffeine (control?)
Report at bed time to sleep lab

48. Dement and Kleitman Ps go to bed in quiet room
Electrodes stuck next to eyes to record eye movements (EOG)
Electrodes stuck to scalp to record brain waves (EEG)
Attached by single wire to EEG (lead wire at top of bed)

49. Dement and Kleitman
Ps then awakened through the night to test their dream recall
Participants were woken on average 5.7 times per night
During or just after REM
Slept on average for 6 hours
Repeated many times

50. Dement and Kleitman Woken by a bell
Then Ps spoke into a recording device
FIRST - they said whether they had been dreaming
NEXT - they said what they were dreaming about (if they could)

51. Dement and Kleitman CONTROL
No communication between experimenter and sleeper until after they told of their dream content
In case the experimenter ‘suggested the content’

52. Dement and Kleitman CONTROL
They were NOT told whether they had been woken in REM sleep or in NREM sleep
Woken in BOTH REM and NREM

53. Dement and Kleitman FINDINGS of 9 participants dream reports (DV1)
REM SLEEP
192 awakenings
152 dream reports (80% could recall a dream)
40 no dream reports (20% could not recall a dream)

54. Dement and Kleitman FINDINGS of 9 participants dream reports (DV1)
NREM SLEEP
160 awakenings
11 dream reports (7% recalled dreams)
149 no dream reports (93% could not recall a dream)

55. Dement and Kleitman FINDINGS of 9 participants
length of dream correlated to length of REM (DV2)
How was this done??
Ps awakened randomly after 5 or 15 minutes of REM and asked to guess how long they had been dreaming
(5 or 15 minutes)

56. Dement and Kleitman FINDINGS of 9 participants 5 minutes REM SLEEP
45 reports were right
6 reports were wrong
15 minutes REM sleep
47 reports were right
13 reports were wrong

57. Dement and Kleitman FINDINGS of 9 participants
relationship between the type of eye movement to CONTENT of dream
(DV3)
Ps woken when TYPE of eye movement was regular (vertical etc)
21 wakings - reports always looking at people or objects near to them

58. Dement and Kleitman FINDINGS: (DV3)
One P woken when TYPE of eye movement was regular (horizontal etc)
Reported watching people throwing tomatoes

59. Dement and Kleitman
SUMMARY & conclusions (with a partner – 5 mins!)

60. Dement and Kleitman SUMMARY & conclusions
regularly occurring REMs every night
lack of dream recall + light brain waves suggest NO dreaming in NREM

61. Evaluation points… What do you think? Methodology Sample
What data was collected?
Ecological Validity
Validity
Usefulness

62. Dement and Kleitman Evaluation REM sleep is important
the brain needs to sleep to organise itself
evidence
babies sleep longer than old people
REM is longer after complex tasks

63. What are the strengths and weaknesses of the method used in the study?
Laboratory studies have high levels of control over variables but may lack ecological validity.
The study used the EEG to measure brain activity and this allows precise measurements to be taken (its scientific and objective).

64. Was the sample representative?
The sample was very small indeed.
Only nine participants were studied in total and only five of these were studied intensively.
This is a very small number of participants to generalise from.
You could argue that physiological processes are likely to be the same in all people but this may not be the case.
It is possible that sleep patterns and in particular, relationships between eye movements and dreaming, vary from person to person and the conclusions drawn from Dement and Kleitman’s research would be strengthened if the same relationships were established in a larger sample of people.

65. What type of data was collected?
The data collected in this study by mostly quantitative.
In relation to the first two research questions, the data is simply numbers of participants who could or could not recall dreams or could or could not accurately estimate the length of their dreams.
Quantitative data is relatively easy to collect and can be analysed statistically.
However, it reduces complex qualitative phenomena to numbers and this often results in a lack of detail in the data.
The data collected in relation to the third question was more qualitative as here participants were asked to describe the contents of their dreams.
This gives us richer and more interesting data but such data is difficult to use for comparisons and is hard to analyse statistically.

66. Was the study ecologically valid?
The research studied participants who went to sleep in a laboratory with electrodes stuck to their head.
It is unlikely that this bears much relation to sleep in a normal environment! It is possible that being in such an artificial condition meant that their sleep was disturbed and if this was the case, the researchers would not have been studying normal sleep patterns.
The participants were also woken up several times during the night and asked about their dreams.
Again, this is unlikely to happen normally and may have had an affect on the way the participants slept.
However, research conducted outside of the controlled conditions of the laboratory would have been unable to measure brain activity and eye movements in the ways.

67. Was the study useful?
The conclusions that were reached by Dement and Kleitman have been replicated by many other researchers.
However, there is one methodological issue that should be considered. In relation to the first research question, Dement and Kleitman conclude that dreaming takes place in REM rather then non-REM sleep.
What they have actually demonstrated is that dreams are recalled more often from REM rather than non-REM sleep and it may be that dreaming does occur in non-REM sleep and it much harder to recall them.

68. When the research was first conducted, very little was known about the relationship between eye movements and dreaming and so Dement and Kleitman’s research really did add new information to what was known about sleep.
It is difficult, nearly fifty years later, to understand what a major breakthrough this study represented.
The use of EEG to record brain activity whilst sleeping was also relatively new and it was not until research like this Core Study, that it became clear that dreams could be studied in an objective way.
Dement and Kleitman’s research generated very many other studies into sleep and dreaming and there have been many useful findings.