Biological Approach 1 - Dement and Kleitman Flashcards
When was this study done?
1957
What is the circadian rhythm?
Your 24hr sleep/wake cycle.
What is an EEG?
An electroencephalograph. It records brain activity and eye movements.
What sort of experimental design is this study?
Repeated measures desgin.
What sort of experiment is this study?
Lab experiment.
How did Dement and Kleitman record participant’s brain waves and eye movements?
EEG and EOC.
What is the first aim?
Does dream recall differ between REM and nREM sleep?
What is the second aim?
Is there a positive correlation between subjective estimates of
dream duration and the length of the REM period before waking?
What is the third aim?
Are eye-movement patterns related to dream content?
What is the first hypothesis?
There is a connection between REM sleep and dreaming.
What is the second hypothesis?
There will be a significant positive correlation between the
length of REM and the estimated length of dreams.
What is the third hypothesis?
There will be a significant positive correlation between eye movements and the content of dreams.
What is the IV?
What stage of sleep (REM or nREM) the subject was woken up in.
What is the DV for hypothesis one?
Dreaming or not.
What is the DV for hypothesis two?
Dream length estimation (5 or 15 minutes).
What is the DV for hypothesis three?
Anecdotal evidence given by the dreamer.
What was used to wake the participants?
A loud, electronic bell.
How did the participants record their dreams?
They spoke into a voice recorder immediately after being woken up.
How many total dreams were recorded?
152
How many dreams were not recorded due to equipment failure or procedural failure transcribing them?
26
How many participants were there?
9: 2 women and 7 men.
How many participants withdrew?
4 (gender unknown).
How was the data of the 9 participants used?
5 were studied in depth, and the 4 that withdrew had their data used to confirm the results of the 5.
What were some rules for the participants?
They were told not to have any caffeine or alcohol before the study.
When would the participants arrive at the study?
Shortly before their normal bedtime.
When would the experimenter ring the bell to wake a participant up?
At the end of a REM or nREM period so that participants could record their dreams. (If they had any).
Why were the periods of dreaming time before being woken up altered?
To see if the estimated length of the dream corresponded to real time.
What was the procedure for hypothesis one?
- Participants were woken after REM or nREM sleep but not told which
- Participants recorded their dream into a recorder right after (if they had one)
How was the choice of being woken up after REM or nREM decided for procedure one?
- Random number generator for two participants.
- 3 REM than 3 nREM for one participant.
- Telling the participant they would only be woken in REM, but waking them randomly. (one participant).
- The experimenter chose. (one participant).
What communication was there between the experimenter and the participants?
Very little.
Sometimes, after describing a dream, the experimenter would come into the room and ask the participant further questions.
What was the procedure for hypothesis two?
Woken after 5 or 15 minutes in REM.
Guessed the duration of their dream.
Sometimes longer REM periods.
Words in dream narrative were counted.
What was the procedure for hypothesis three?
EEG electrodes detect eye movements.
After 1 minute of a consistent eye movement, the participant was woken and asked to report their dream.
What were the four types of eye movements experimenters looked for?
Mainly vertical
Mainly horizontal
Both vertical and horizontal
Little or no movement
How did the experimenters compare the EEG results of the participants?
They took EEGs of awake participants who watched distant and close up activity.
How many people had EEGs while they were awake for comparison?
5 participants
and
20 people outside the experiment.
What is an example of a dream that has mainly horizontal eye movement?
Throwing a tomato back and forth.
What is an example of a dream that has mainly vertical eye movement?
Climbing a ladder
Throwing basketballs
What is an example of a dream that has mainly little or no eye movement?
Driving a car
Watching people in the distance
What was the result of hypothesis one?
TRUE
There is a connection between REM and dreaming.
What was the result of hypothesis two?
TRUE
There will be a significant positive correlation between the
length of REM and the estimated length of dreams.
What was the result of hypothesis three?
TRUE
There is a correlation between the direction of eye movements and the content of dreams.
How long did uninterrupted dream stages typically last?
3-50 minutes
Approx. 20 min. for the mean
Were dream stages typically longer earlier or later in the night?
Later.
Were rapid eye movements detected in the onset of sleep?
No.
How varied was cycle length?
Different between participants, but consistent with each participant.
When participants were woken from nREM sleep, which sleep did they return to?
nREM.
When participants were woken from REM sleep, which sleep did they return to?
nREM. Except for late in the night when their body was trying to catch up on REM sleep.
What conclusion can be drawn between dreaming and REM sleep?
Dreaming is reported from REM but not nREM sleep.
What conclusion can be drawn about participants estimating dream length?
Participants can judge the length of their dream duration.
What conclusion can be drawn between eye movement patterns and dream content?
Eye patterns do relate to dream content.
Why was their occasional recall of dreams from nREM stages?
Likely because dreams are being recalled from the previous REM stage.
What are results in an experiment?
The actual data uncovered by the experimenters often in numerical detail.
What are conclusions in an experiment?
The inferences of the results and the interpretation of the results.
What were the strengths of this experiment?
Lab experiment - standardised environment
Controlled extraneous variables
Quantitative data
Reduced demand characteristics due to the participants not being told about their brain waves
What were the weaknesses of this experiment?
Low ecological validity
Small sample size - low generalisability
Self-reporting - could be influenced by participant’s personality rather than actual dream length
Sleep lab affected quality of sleep
What is the GRAVE analysis of this experiment?
medium
high
medium
medium
high
How could this study be improved?
A larger sample size
OR
Conducted in a participant’s home instead of a laboratory
