Transcript Dement and Kleitman (1957) REM and dreams

Dement and Kleitman (1957)
REM and dreams
The relation of eye movements during
sleep to dream activity: An objective
method for the study of dreaming
Journal of Experimental Psychology 53
pp339 - 46
psychlotron.org.uk
Mark Souter
Dement and Kleitman (1957) REM and dreams
introduction
• long standing point of interest
• tradition of dreams as prediction
• tradition of dreams as subconscious mind
• D&K => breakthrough re frequency &
length of dreams
• also relationship of dreams to health
psychlotron.org.uk
Mark Souter
Dement and Kleitman (1957) REM and dreams
the study: starting points
• D&K noticed rapid eye movement (REM)
• apparent connection with dreaming
• 3 Qs
• 1 does dream recall correlate to REM?
• 2 is there a correlation between REM duration
and estimates of dream length
• 3 is REM connected to content of dreams?
psychlotron.org.uk
Mark Souter
Dement and Kleitman (1957) REM and dreams
the study: subjects
• 9 adults: 7M 2F
• 5 studied intensively
• 4 minimal data to confirm data on 5
psychlotron.org.uk
Mark Souter
Dement and Kleitman (1957) REM and dreams
the study: procedure
• S report to lab before bedtime
• asked to eat normally BUT avoid caffeine /
alcohol on day of study
• 2 electrodes near eye (record muscle
activity)
• 2 or 3 others record brain activity
• electroencephalograph (EEG)
psychlotron.org.uk
Mark Souter
Dement and Kleitman (1957) REM and dreams
the study: procedure
• woken at various times to test dream recall
• bell woke S - they recorded dream recall on tape
[why?]
• (to avoid experimenter effects)
• waking times:
–
–
–
–
2x random;
1x at whim of experimenter (!);
1x 3xREM + 3xnREM;
1x random (told only during REM)
psychlotron.org.uk
Mark Souter
Dement and Kleitman (1957) REM and dreams
the study: procedure
• 'dream' only counted if recall clear
• return to sleep <5 mins
• 9 S studied over 61 nights: 351
awakenings (av 5.7 per night)
• Subjects awakened as soon as four
predominant pattern of movement had
persisted for at least 1 minute
psychlotron.org.uk
Mark Souter
Dement and Kleitman (1957) REM and dreams
results: REM patterns
• all subjects showed REM every night
• REM had regular pattern
• pattern varied per individual
• av gap 90 mins - norm 70-104 mins
• duration of REM 3 - 50 mins
psychlotron.org.uk
Mark Souter
Dement and Kleitman (1957) REM and dreams
results: REM–EEG patterns
• REM correlates to EEG patterns
• REM EEG - low voltage fast pattern
results: REM–dream reports
• reports of dreams correlates strongly to
REM sleep
• few dreams reported in non-REM sleep
psychlotron.org.uk
Mark Souter
Number of wakenings associated with recall or no recall of dreams after REM and
non-REM sleep
160
152
149
140
120
100
80
60
39
40
20
11
0
REM dream reacall
REM no recall
non-REM dream recall
psychlotron.org.uk
non-REM no recall
Mark Souter
Dement and Kleitman (1957) REM and dreams
results: deep sleep - dream reports
• in deep sleep (indicated by EEG) Ss
reported confusion
• reported thinking that they had been
dreaming …
• but could not describe dreams
• often reported strong emotions
psychlotron.org.uk
Mark Souter
Dement and Kleitman (1957) REM and dreams
results: dream duration – REM estimates
• woken 5 or 15 mins in REM and asked to
estimate duration of dream
• strong correlation between estimates and
REM times
• i.e. most subjects could usually estimate
times accurately
psychlotron.org.uk
Mark Souter
Results of dream-duration estimates 5 or 15 minutes after onset of
REM - Average accuracies
10
9.4
9
9
8
7
6
5
4
2.6
3
2
1.2
1
0
after 5 mins - right
after 5 mins - wrong
after 15 mins - right
psychlotron.org.uk
after 15 mins - wrong
Mark Souter
Dement and Kleitman (1957) REM and dreams
results: eye movement - dream content
• a) vertical eye movement > operating a hoist
• b) Horizontal > throwing tomatoes
• c) Both vertical & horizontal > talking to people
close to them (friends)
• d) Very little or no movement > staring at fixed
objects.
psychlotron.org.uk
Mark Souter
Dement and Kleitman (1957) REM and dreams
discussion: the study
• well controlled lab experiment
• small sample
• (may be less important because study of
physiological condition rather than
psychological)
• breakthrough in dream research
• close correlation REM - dreams
• nature of relationship remains unclear
psychlotron.org.uk
Mark Souter
Dement and Kleitman (1957) REM and dreams
discussion: later studies
•
•
•
•
•
Goodenough et al
self reported hi/lo dreamers
hi dreamers - many REM-dream links
lo dreamers - much lower REM-dream link rates
 highly variable
psychlotron.org.uk
Mark Souter
Dement and Kleitman (1957) REM and dreams
discussion
•
•
•
•
•
Dement and Wolpert
tried to influence dreams
sprayed water, flashed lights, played tones
some influence on a few subjects
people blind from birth and newborns show REM
psychlotron.org.uk
Mark Souter
Dement and Kleitman (1957) REM and dreams
discussion: variations in D&K’s results
• the following tables indicate variations
between subjects
• they use data on the 5 main subjects
• variations do not fatally undermine D&K’s
study, but should serve to show that we
need to be cautious about generalisations!
psychlotron.org.uk
Mark Souter
DN
KC
PM
KC
DN
PM
REM dream reacall
REM dream reacall
REM no recall
REM no recall
non-REM dream recall
non-REM dream recall
non-REM no recall
non-REM no recall
WD
IR
IR
KC
WD
REM dream reacall
REM no recall
REM dream reacall
REM no recall
non-REM dream recall
non-REM no recall
psychlotron.org.uk
reacall
REM dream
non-REM
dream
recall
REM no recall
non-REM dream recall
non-REM
no recall
non-REM no recall
Mark Souter
Results of dream-duration estimates 5 minutes after onset of REM
15
10
5
0
DN
IR
KC
WD
PM
after 5 mins - wrong
2
1
0
1
2
after 5 mins - right
8
11
7
13
6
psychlotron.org.uk
Mark Souter
Results of dream-duration estimates 15 minutes after onset of
REM
15
10
5
0
DN
IR
KC
WD
PM
after 15 mins - wrong
5
3
1
1
3
after 15 mins - right
5
7
12
15
8
psychlotron.org.uk
Mark Souter