DEMENT AND KLIETMAN (Methods/procedures) Flashcards
Initial stage
Arrival, rules, setting, materials, timing
Arrival: Ppts reported to the lab before their personal bedtimes .
Rules: Day prior to the study, ppts couldn’t drink alcohol or caffeine.
Setting: They slept in a dark quiet room.
Materials: they were fitted with an EOG electrode near their eye and EEG electrodes at the scalp. Wires were gathered into ponytail to allow freedom of movement. Doorbell used to awoken all ppts at from REM/NREM
Ppts always returned to sleep within 5 mins
QUESTION 1: Does dream recall differ between REM and NREM stages of sleep. (PROCEDURE)
1) PPTS were either awoken during REM/NREM but were not told which. The choice of how and when they would be woken up was decided in different ways
2) RANDOM NUMBER TABLE: 2 PPTS were woken according to the table.
RANDOM CHOICE: 1 ppts was woken on the whim of the experimenter.
RANDOM GROUPS: 1 ppts were was woken during 3 REM and NREM periods. Awoken using an doorbell next to the bed.
3) AFTER BEING AWOKEN: PPTS stated whether they dreamt or not. Describe the dream content into a tape recorder (next to the bed) The experimenter would occasionally enter the room to ask further questions about the dream.
QUESTION 1: Does dream recall differ between REM and NREAM stages of sleep. (Results)
REM: Awakening from REM resulted in dream recall of 79.6%.
NREM: Awakenings from NREM resulted in dream recall of 7%.
Differences in dream recollection were marked at the end of the NREM period with only 6 dream recall/132 awakenings.
Ppts tended to describe feelings but not specific dreams content.
QUESTION 1- (Conclusions)
REM
1) PPTS recalled dreams frequently during REM awakenings but rarely in NREM awakenings.
2) Dreaming probably occurs only during REM
NREM
1) Dreaming recalled from NREM are mostly likely being recalled from previous REM stages.
Question 1 - methodology
Repeated measures design
Natural experiment
IV= REM/ NREM keep
DV= Whether a dream was recalled
Question 2: Is there a positive correlation between subjective estimates of dream duration and the lengths of REM period before waking?
Procedure
1) PPTS were woken either 5/15 mins after REM began. Asked to estimate dream duration between 2 options (5/15mins)
2) Dream content and length of the narrative (words) were correlated with REM sleep duration.
Question 2: Is there a positive correlation between subjective estimates of dream duration and the lengths of REM period before waking?
Results
PPTS were mostly accurate in their dream duration estimations.
1) 88% of trials= ppts estimated 5 mins correctly.
78% of trials ppts estimated 15 mins
2) There was a significant positive correlation between REM duration X (number of words in a) dream narrative. (R=0.71)
Question 2: Is there a positive correlation between subjective estimates of dream duration and REM duration?
Conclusions
Ppts can judge the length of dreams duration accurately. Thus dreams are not instantaneous events but are experienced in real time.
Question 2- methodology
RMD
Correlational study
Co variable 1 = Dream duration
Co variable 2= REM duration
Question 3: Are eye movements patterns related to dream content (procedure)
1) Ppts were woken as soon as 1 of 4 eye movement patterns were detected on EOG for a min
2) Then they were asked what they had been dreaming about.
3) Comparison EEG records were taken from ppts who were awake and were asked to watch distant/ close up activity.
Question 3: Are eye movements patterns related to dream content (results)
Periods of Mainly Vertical/horizontal eye movements were rare.
Eye movement patterns compared to control showed similarities in EEG readings.
Mainly vertical eye movement
Standing at the bottom of a tall cliff operating a hoist.
Climbing a series of ladders, looking up and down as he climbed.
Mainly horizontal eye movement
Watching 2 ppl throw tomatoes at each other.
V + H eye movement (mixed)
Associated with looking at objects or people close to them. Talking to a group of people. Fighting with someone.
Non little eye movements
Watching something at a distance or staring at an object
Driving a car and staring at the road ahead. He approached the road junction and was startled by a car appearing suddenly to his left
Question3- are eye movement patterns related to dream content (conclusions)
Eye movements during REM sleep correspond to where/what the dreamer is looking at in the dream.
Thus rapid eye movements are not caused by activation of the CNS (not random) but are related to dream imagery.
Question 3- method
Natural experiment
Self reports were compared to direction of eye movements
How was the mean sleep cycle calculated?
Total sleep cycle in mins + every complete sleep cycle.
What type of study was the Dement and Kleitman study?
Lab experiment
Data was collected with self report measures (recorder)
Describe the sample
7 males
2 females
(5 studied in detail/ 4 were used to confirm these results TSA)
Materials used?
Sleep lab
EOG
EEG
Doorbell
Tape recorder
What is the studies aim?
- To investigate whether dream recall differs between REM and NREM sleep stages.
- Whether there is a positive correlation between subjective estimates of dream duration and rem duration before waking
- Whether eye movement patterns related to dream content
Describe the procedure from when the ppts arrived at the lab until the ppts fell asleep for the 1st time.
- ppts were told to eat normal and refrain from caffeine/alcohol that day.
- Each ppt had 2+ electrodes placed near their eyes.
- 2 or 3 electrodes placed on the scalp.
- ppts went to bed in a quite, dark room
Why did the researchers use EEGs to measure brain activity?
- It is a consistent, objective, reliable measure to measure brain activity
-identify when a person was in REM/NREM sleep
Examples of standardisation in the study
-Doorbell used to waken ppt
-How fast the EEG/EOG machines ran
-Recall dream then guess duration of dreaming and narrate dream content
Real world application
- EEGs can detect REM/NREM sleep so can be used to diagnose sleep disorders/ problems
- Find a treatment to help with any sleep disorders
- Psychologists can use EEG output to see how their sleep patterns are different from normal sleepers
How did researchers initially attempt to measure ppts estimates of REM duration?
- ppts were woken up at different time increments (in REM)
- asked to estimate dream duration to the nearest min.
- no fixed choice
EEG can detect…
REM/NREM sleep
Name all the controls used in the experiment
- Door bell
- experimenter questions only asked when ppts completed the recording, 3. reports not counted if ppts only had a vague impression of a dream with no specific details.
- Deception (not told about EEG patterns).
- Ppts would record dreams immediately into recorder.
- No caffeine/ alcohol.
