Dement and Kleitman - Sleep and Dreaming Flashcards

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1
Q

What are the 3 research questions?

A

1: does dream recall correlate with periods of REM sleep?
2: is there a correlation between the estimate of dream length and the time spent in REM?
3: if there is a relationship between pattern of eye movements in REM and dream content.

There were 3 different studies to collect data for research questions.

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2
Q

What do we already know before study?

A

There is a sleep cycle –>People go through different stages while they’re asleep.

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3
Q

Research method

A

Controlled observation

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4
Q

Research design

A

Quasi experiment in a lab setting.

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5
Q

What is the IV?

A

Woken in NREM or REM

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6
Q

What is the DV?

A

Whether the participant dreamed or not

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7
Q

Sample size?

A

9 total.

7 men, 2 women.

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8
Q

What type of sample was it?

A

Volunteer sample.

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9
Q

How many nights were the example studied for?

A
5 studied intensively (6-17 nights)
4 studied (1-2 nights)
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10
Q

Why was there a difference in number of nights some of the sample were studied for?

A

4 participants were used as a control to confirm the findings.

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11
Q

What was the setting of the experiment?

A

Quiet and dark laboratory

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12
Q

What apparatus were used?

A

-Recording device and apparatus to make a loud doorbell noise.
-Electrodes placed:
~ near corners of eyes to measure eye movement (EOG)
~ on scalp to record brain activity (EEG)

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13
Q

What did they sleep attached to?

A

EOG
EEG
EMG

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14
Q

EEG=

A
  • measures brain activity
  • electrodes placed over head

(Electroencephalogram)

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15
Q

EMG=

A
  • measures muscle activity
  • electrodes placed on the jaw

(Electromyogram)

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16
Q

EOG=

A
  • measures eye movement
  • Electrodes placed across the eye socket

(Electro-oculogram)

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17
Q

General Procedure …

A

1: participants avoided caffeine and alcohol for a few days beforehand
2: participants individually went to sleep in a laboratory at the end of a normal day. They arrived at the lab just before their normal bedtime.
3: electrodes attached and run continuously throughout the night.
4: the experimenters woke the participants at various times using the doorbell noise
5: the participants immediately reported whether they had been dreaming and if so, the dream content into the recorder.

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18
Q

Study 1 procedure

A

Participants woken in one of four ways…

1: 2 woken randomly
2: 1 woken during 3 REM periods followed by 3 non-REM periods
3: 1 woken at random but told would only be woken during REM sleep
4: 1 woken at whim

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19
Q

Study 2 procedure

A

Participants woken 5 or 15 mins after REM began and asked if the dream lasted closer to 5 or 15minutes

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20
Q

Study 3 procedure

A

Participants woken as soon as one of 4 patterns of eye movement has occurred for 1 minute, and asked what the dream was about

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21
Q

What were the 4 patterns of eye movement?

A

1: Mainly vertical
2: Mainly horizontal
3: Vertical and horizontal
4: Very little/no movement

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22
Q

Why were they told not to have alcohol or caffeine?

A

As they are both stimulants and keep you awake.

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23
Q

Why may no alcohol or caffeine have affected the study?

A

This may affect their usual behaviours as it is not their usual routine.
However researchers wanted a baseline of all participants the same so the study is reliable.

However if it usually part of the participants daily routine then it may have affected their normal sleeping pattern. Also they may have accidentally/unknowingly ingested it.

24
Q

What were the controls in this study?

A
  • All participants slept in the same room but they were tested individually (the study was carried out over a period of time- 2/3 participants in a room per time)
  • A buzzer wakes them at odd intervals, not contact with an experimenter = all woken in same way
  • They describe their dream into a tape recorder, all done before contact with an experimenter
  • They are woken on average 5.7 times a night, 6 hours sleep (did not want experimenters going in all the time)
  • Participants never told if their eyes had been moving before being woken
  • Experimenters only asked about their dream content once they had stated they were dreaming. Therefore this was not leading.
  • No caffeine or alcohol.
25
Q

Issue in study

A

Got info about dreams through self report

26
Q

In study 1 why were the participants not told whether they had been in REM or NREM?

A

It was a blind procedure so they could not respond to demand characteristics.

27
Q

What happened in the pilot study?

A

Participants were asked to estimate the length of dreaming (for study 2) but this prove difficult so that is why they were woken 5 or 15 minutes into the study.

28
Q

Aim

A

To investigate if there was any association between REM sleep and dreaming

29
Q

How did they know how long they had been sleeping in study 2?

A

Through the EEG measuring brain activity

30
Q

How did the researchers know what the participants eye patterns were in study 3?

A

The EOG machines

31
Q

What are the benefits of using the same measurements to monitor the participants?

A

The results are reliable as there is consistency across all participants

32
Q

What are the benefits of the participants being tested individually?

A

So you could collect results across individual participants and compare

33
Q

What are the benefits of using a tape recorder to record participants?

A

It is an objective measure.

No human error or mistakes.

34
Q

What are the benefits of the participants having no contact with the experimenter?

A
  • avoids disruption… They can just wake up and record

- participants are woken in the same manner

35
Q

What are the benefits of using a doorbell noise to wake up the participants?

A

All the participants are woken in the same manner and environment. Therefore high reliability.
Also high ecological validity as similar to what people are normally woken up to.

36
Q

What are the benefits of using the same sleep laboratory?

A

Increases reliability

37
Q

What are the benefits of no alcohol or caffeine?

A

Everyone is the same and there is no effecting substance.

38
Q

What is there no control over?

A

No control over other actions in the day eg. eating and exercise

39
Q

Results of study 1

A

More dreams, were reported in REM than non-REM sleep, regardless of how the participants were woken.

REM:
~ Dream: 152
~ No recall: 39 - could be explained as forgot dreams. This also tended to be in the earlier periods of the night
~ Total 191

NREM:
~ Dream: 11 - usually within 8 mins of REM sleep, therefore could be explain by remembering a dream from a previous state
~ No recall: 149
~ Total 160

40
Q

Qualitative measure

A

Self reports

41
Q

Quantitative measures

A

EEGs
EOGs
Estimation of dream length
Observation of eye movements

42
Q

Ecological validity

A

A lack of ecological validity as the participants had to sleep in a laboratory and have electrodes on them. Both are unusual.

43
Q

Results of study 2

A
  • Participants could not estimate this, so researchers randomly woke them after 5 or 15 mins of REM and asked them to guess.
  • Most participants correctly matched dream duration to tie in REM, which suggests dreams are in ‘real time’.

5mins after awakening:
~ 88.2% right
~ 11.8% wrong
~ Match: 45, No Match: 6, Total: 51.

15mins after awakening:
~ 78.3% right
~ 21.7% wrong
~ Match: 47, No Match: 13, Total: 60.

  • There was a significant relationship between length of dream (no. words in dream report) and length of REM
  • The higher amount of wrong estimates after 15mins suggested that the longer they had been in REM the less accurate they were at estimating dream length.
44
Q

What should be done to improve study 2?

A

There should have been more trials. Therefore eliminating the element of guessing.

45
Q

Results of study 3

A
  • A very strong association between eye movement pattern and dream content.
    ~ Vertical eye movements: associated with dream of ladders.
    ~ Horizontal: watching people throw tomatoes at each other
    ~ Vertical and Horizontal: looking for something
    ~ No movement: Staring at an object
  • results suggest that eye movements were related to dream content, indicating that eyes are moving in specific directions are seeing what the participants are dreaming about.
46
Q

3 Conclusions

A

1: Dreams are related to REM sleep
2: People do dream in real time
3: Eye movements are closely related to dream content

47
Q

Issues with sample

A
  • A limited sample (mostly men)

- Sample may be too small to be representative

48
Q

What are the confounding variables in this study?

A
  • Sleeping in a lab and being connected to electrodes could affect their sleep patterns
  • The waking method could have affected their dreaming/sleep patterns, as could be woken several times in one night.
49
Q

Is this study generalisable?

A

No, as there was a limited sample, mostly using men and the findings lack generalisability.

50
Q

How was observation used in this study?

A

To detect eye movements

51
Q

How useful is this study?

A

This research shows that dreams can be studied in an objective way.

52
Q

Limitation of study 2

A

A closed question was used, therefore it was much easier for participant to guess the duration of dreams correctly.

53
Q

Does this study have ecological validity?

A

Yes, as the subjects are aware of what is happening and are woken by doorbell, hence similar to what people normally wake up to.

No, as not normal sleeping environment and strapped into electrode machines.

54
Q

3 changes to the study

A

1: Carry out study in participants homes instead of laboratories
2: Sample
3: Change method… Dream diary and questionnaire.

55
Q

What does an EEG measures?

A

Electrical activity in the brain

56
Q

Limitation of using EEG to investigate dreaming

A
  • indicates electrical activity but does not explain why the activity is taking place. The activity may not be caused by the participant dreaming but by some other factor.
  • does not establish cause and effect. Here one cannot say the cause of increase brain activity is because the participant is dreaming because other factors may be the cause.
  • attachment of EEG to scalp may interfere with sleep pattern therefore does not reflect an individual’s normal sleep pattern.