Dement and Kleitman Flashcards
Psych being investigated (3)
- EEG measure brain activity, used to measure amplitude and frequency of brain waves
- REM is a phase wen a person is paralysed- their eyes flicker and they can breath but their muscles are paralysed
- nREM are other stages of sleep with differing brain activity
Aim 1 (do we?)
To test/ investigate whether dreams occur during REM or nREM using an objective technique
EEG full form
electroencephalograph
Aim 2 (pattern and content)
To test the pattern of eye movement (nREM or REM) and the content of the dream
(Are eye movement patterns related to dream content? )
Aim 3 (pattern and duration)
To investigate the pattern of eye movements and the duration of the dream
Aim 4 (how long _ and _ is )
To test whether there was a positive correlation between subjective estimates of dream duration and the length of the REM period before waking?
Method
Lab
Design
Repeated measures
Data collected how?
Self-report
IV (2)
- when the participant is woken up
- whether the ppt is in nREM or REM
DV (3)
- duration and content of dream
- whether or not the ppt was dreaming
- pattern of eye movement
Sample details (4)
- 9 in total
- 7M and 2F
- 5 used actively while 4 were used to confirm the results
- opportunity
Where were the electrodes connected? (2)
Scalp and near the eyes
Why were electrodes connected at eyes
to measure eye movement
Why were electrodes connected at the scalp
To measure brain waves as a criterion for depth of sleep
What was the average sleeping time
6 hours
Average nightly awakenings
5.7
Type of interview
Semi-structured
Details on the interview (3)
- spoke into a recording device when woken up
- instructed to state whether they were dreaming
- told to explain content of the dream
Criteria for not considering the dream
not detailed and coherent
How were electrodes tied?
in a single chord above the bed
why were electrodes tied in this manner? (2)
- to ensure subjects could freely move
- to avoid entanglement
Why was REM not observed in the initial onset of sleep?
because REM occurs in the later stages of sleep
Two pieces of evidence that dreams occur during REM
- most subjects recall dreams during REM not nREM
- During nREM awakenings, most subjects could not recall the content of the dream and had feelings to describe such as anxiety, detachment
How were participants awoken in the test for the pattern of eye movement and content of the dream? (2)
- according to the four patterns observed
- if the pattern persisted for at least 1 minute, they were asked to describe the content right before awakening
what were the four eye patterns
- vertical
- horizontal
- both
- none
Dream recall results (3)
- subjects showed a high incidence of dream recall when awoken in REM as compared to nREM
- some subjects had better recall than others
- Dream recall during nREM are accounted for by assuming that the memory of the preceding dream persisted for an unusually long time
Participant variable example
some ppt recalled dreams better than others
REM lasted how long (3)
3 minutes to 50 minutes
mean of 20 minutes
longer later during the night
Relationship between dream narrative and REM duration
positive correlation
occurrence of rapid eye movement
- observed every night
how were demand characteristics reduced
- subjects were not informed when awakened whether their eyes were moving or not
dreams during vertical eye movement (3)
- standing at the bottom of a cliff and operating a hoist
- climbing a ladder,
- throwing basketballs then looking down to pick up another ball
Dreams during horizontal eye movement (1)
- subject watched two people throw tomatoes at each other
Dreams during fixated eyes (2)
- watching something fixatedly
- looking at something far away
Mixture of movements dreams (3)
discussion, fighting, talking
instructions given to ppts (3)
- do not drink alcoholic/ caffeine containing beverages
- eat normally
- report to lab before bedtime
how was sleep made natural
went to bed in a quiet dark room
how were subjects woken up?
using a doorbell
how is the study objective
- studying dream activity using physiological equipment is an objective method.
- dreaming is a subjective concept by nature but it becomes objective when it is related to some physiological phenomena, which can therefore be measured.
Conclusion of the study (3)
- Dreams probably occur only during REM sleep as when awakened during REM, they had dreams. When awoken during nREM, dreams recalled from previous dreams
- Eye movements while dreaming constitute to the actual dream content
- REM duration was directly proportional to dream length
Mean of REM sleep
20 minutes
how many total negative reports of dream recall during REM
39
Describe negative reports of dream recall
19 occurred after awakenings during REM periods falling in the first 2 hr.of sleep,
11 after REM awakenings during the second 2 hr., 5 in the third 2 hr., and 4 in the last 2 hr.
How was unintentional cuing reduced?
There was minimal contact between the experimenter and the subject
The three approaches used in testing the correlation between eye movements and dreaming:
i. Dream recall during REM
ii. Subjective estimate of the duration of dreams compared to duration of eye movements
iii. Pattern of eye movements was related to the dream content to test whether they represented a visual representation of the dreams
How often did REM take place
Every night
When was dream recall most likely to occur
during REM
How many reports were there of dream recall during REM
recall 152
How many reports of dream recall were there during nREM
recall 11
How was order of waking up for dream estimation chosen
randomly
Describe DN dream estimate
equally likely to get 5 minutes wrong and 15 minutes wrong
- got estimation of 15 minutes 50% of the time
Data for dream duration estimates
45/51 got 5 minutes right
47/60 got 15 minutes right
Why can we not create an accurate appraisal of the mean duration of REM periods
As most REM periods were terminated artificially by an awakening
DM and WD averaged one eye movement every __ mins
70 and 75
Average for whole group was one REM period every __ mins
92
How was DN awoken
a pattern of 3 REM, 3 nREM
How were PM and KC awoken
According to a table of random numbers
How was WD awoken
randomly
although he was told he would be awoken only when he was dreaming
How was IR awoken
at the whim of the experimenter
What happened when participants were awoken during deep stage of sleep (3)
- felt as though they weren’t dreaming
- could not remember any dream
- felt anxiety, pleasantness, detachment
Describe strength of standardised procedure
- standardised procedure increases reliability
- e.g ppt was always in a quiet dark room making replication to test for reliability easy
Describe first attempt to measure participants estimations of REM duration (3)
- participants were woken up at different points in REM
- asked to estimate time they had been dreaming
- to nearest minute
Describe revised procedure to measure estimation of REM duration (2)
- participants were either woken up at 5 or 15 minutes
- then asked to choose if they had been dreaming for 5 or 15 minutes
Real life application (2)
- EEG can detect REM/ nREM so can be useful in diagnosing problems with these so that treatment can be found
- EEG can detect REM/ nREM so can be used to help people with sleeping disorders. A psychologist can use the EEG to see how their sleep patterns are different to a normal sleeper
