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Dement and Kleitman
Transcript of Dement and Kleitman
Who dreamed last night? What did you dream?
Who's had a recurring dream?
Theories of Dreaming
Why we sleep: There are many theories about why we sleep. Evolutionary psychologists believe that all of our functions help us survive- Perhaps laying dormant helped us avoid detection from predators. It is also clear that our body uses sleep time to recover and repair itself.
The 5 stages of Sleep
Dr Kleitman did a lot of work on sleep before this study, and one of things he investigated was the human sleep cycle, and the brain waves which occur in different stages 1-5
Cycle lasts approx 90-110 minutes and repeats
This lasts around 10 minutes. Our muscle activity slows down and slight twitching may occur, we can be awakened easily at this stage.
This lasts around 20 minutes. The breathing pattern and heart rate start to slow down.
This lasts 40–50 minutes and the brain begins to produce delta waves, a type of wave that is high amplitude and low frequency. Breathing and heart rate are at their lowest levels.
This lasts about 20 minutes and the brain is very active – often more so than when we are awake. Our brain also cuts off the release of chemicals which are responsible for muscle response- effectively paralysing us during REM
The REM stage is so called for the Rapid Eye Movements that occur in this stage. Because of this eye movement and increased brain activity
Kleitman wondered if this stage is when we dream.
To rigorously investigate the relationship between Rapid Eye Movements and Dreaming
1. There will be a significant association between REM sleep and dreaming.
There will be a significant positive correlation between the dreamers' estimate of the duration of dreams and the length of time spent in REM
There will be a significant association between the patterns of Rapid Eye Movement and the context of the dream
What do physiological psychologists believe about the way psychology should be studied?
Clinical study under
IV (H1) REM/ Non-REM
DV (H1) Report of dreaming
IV (H3) Pattern of eye movement
DV (H3) Content of reported dream
9 Participants in all- 7 male & 2 female.
5 were studies in detail, 4 were used to
confirm the results
An electroencephalograph (EEG) was used
to measure brain activity, electrodes were
used to measure REM. Bells were used to
wake participants and recorder to record
Participants (PPs) were tested individually.
PPs were asked to report to the sleep lab around their normal bedtime.
PPs were asked to avoid alcohol and caffeine on the day of the study
Electrodes were attached to PPs heads and faces.
PPs slept alone in a dark room and brainwaves were measured throughout the night.
At various times in the night some REM some NOT PPs were awoken by a bell. They would then record into a tape recorder whether or not they were dreaming, and would have to describe their dream.
To control variables there was no contact with the experimenters participants did not which stage they were woken in, and different PPs were awoken at different times
Two were awoken randomly
One was awoken 3x REM then 3x Non REM
One awoken randomly but believed it was only REM
One awoken at the whim of the experimenter
Participants were awoken EITHER 5 of 15 mins into REM and asked to choose if they had been dreaming for 5 OR 15 minutes
How many words in their description of the dream was also a factor in this correlation- more words means a longer dream
Participants were awoken as soon as one of 4 eye patterns had emerged for 1 minute and aksed exactly what they had dreamed
Mainly vertical eye movements
Mainly horizontal eye movements
Both horizontal and vertical eye movements
Very little or no eye movements
General findings, REM periods were clearly observed
in all participants a distinguishable from Non-REM.
REM was at regular intervals usually around 98 mins.
Create a mind map of the results on A3 paper. Be prepared to feedback and add results you didn't have.
Turn to the original study in your booklets.
Look at table 2 on page 341 for hypotheses 1
Then table 4 on page 343 for hypotheses 2
Read the last 2 paragraphs of page 343, page 344 and the first paragraph of 345.
You may also use the text book
Remember, for your exam you need to make a point, give it some context and explain it- Yellow- Pink- Green, Use highlighters in your mind map to help you know which is which.
Context for results, needs to be specific results- so mention conditions, numbers or quotes.
The findings of Dement and Kleitman's study strongly support a connection between REM sleep and Dreaming, however it cannot be stated with complete certainty that this is the only time we dream.
Dreams are not instantaneous but seem to occur in time comparable to real experiences of the same sort.
The use of EEG and REM sleep allow dreaming to be measured objectively and scientifically and should be used in further research
PPs reported more dreams in REM stages and Less in Non REM
152/191REM wakings 11/160 Non Rem wakings
19/39 no dreams in REM were earlier in the night
In Non-REM more likely to recall a dream within 8 mins of REM
There was a significant correlation between REM length and estimated length of dreams (p<0.05) (The probability of it being by chance is less than 0.05)
There were more correct estimates than incorrect estimates 92/111
More incorrect estimates 13/60 in 15 min REMs than 5 min REMs
There was a significant correlation between length of dream narative and time in REM
The study suggests eye movement is related to dream content
There was a positive association between direction of eye movement and what PPs were looking at in their dream
eg- 1 PP had mainly horizontal movements a dreamed about people throwing tomatos
Give one more conclusion from this study
What was the first hypothesis of this study?
What was the second hypothesis of this study?
What was the aim of Dement and Kleitman's study?
What was the this hypothesis of this study?
What was the method of this study?
How many PPs were there in total?
How many were studied in detail?
How many men and women?
When did PPs go to the sleep lab?
What was the basic procedure/ instructions for the PP?
How many were woken randomly?
How many were woken at the whim of the experimenter?
What was the procedure for hypothesis 1?
What was the procedure for hypothesis 2?
What was the procedure for hypothesis 3?
Can we tell REM and NON-REM apart?
How many dreams were recalled in REM?
How many dreams were recalled in NON-REM?
Describe the correlation between length of time in REM and the estimated length of the dream?
Give one example of the results supporting Hypothesis 3
What can we conclude from the results for Hypothesis 1?
What can we conclude from the results for hypothesis 2?
METHOD AO2 +
Tight controls of extraneous variables which increases internal validity. (eg?)
Use of technology (eg?) which allows us to make accurate and reliable measurements of REM sleep and brain activity.
Quantitative data collected (eg?) which allows us to show clear relationships between REM and dreaming.
Correlations support hypotheses showing relationship between REM and Dreaming which increases the ??? validity of the findings about?
Low-Ecological validity (Why?) Which may have affected PPs sleep patterns. (So we cannot?)
Nature of waking/ self report may have affected ability to recall dream. which would reduce the? as they may not remember.
Sample size was very small and their were more males than females which makes the sample (what?) so it is hard to (what?) about (what?)
Relationship between eye movement and content has not been supported in other studies so this finding is not (what?) so not (what?)
Correlations do not show cause and effect- may be another variable and the link is coincidental
Ethics AO2 +
Mostly ethical study
Participants gave informed consent
No harm or stress caused
Implications AO2 +
Dement and Kleitman's study was the first attempt to study dreaming scientifically so has been very useful as a starting point for further research.
Showed a relationship between REM and Dreaming for the first time
Exam Questions Section A
Identify two substances participants were instructed to avoid the day before the study? 
Outline 1 problem of instructing PPs to avoid these substances... 
Exam Questions Section B Task
I want you to get into groups of 4- within the Freudian/ Jungian halfs
Each Group will be given: An Exam Question, Pens, A3 Paper
1: In your groups you need to reed the question
2: Decide if it's AO1/ AO2 or both- How to answer
3: Answer it (you may use your notes)
4: Names your work and label it Freudian or Jungian
1: Each group is to rotate a place clockwise
2: Read through the mark scheme
3: Using the highlighters mark the work
4: Give a comment