DEMENT AND KLEITMAN STUDY BA. Flashcards
AIM
To find objective methods to demonstrate a relationship between dream content and physiological indicators of dreaming, such as eye movements.
Specifically, They wanted to invesitigate:
1: Does dream recall differ between REM and NREM sleep stages?
2: Is there a positive correlation between subjective estimates of dream duration and the length of the REM period before waking?
3: Are eye movement patterns related to dream content?
BACKGROUND INFO
-Akerinsky and Kleitman’s 1995 study revealed participants woken from REM were more likely to report vivid, visual dreams than those woken from non REM sleep
-Research demonstrated that sleep consists of several alternating stages, including REM+NREM periods
-This groundbreaking work established the link between REM sleep and and dreaming, whilst also revealing the cyclic nature of sleep stages, laying the foundation for modern sleep science.
PROCEDURE
1) During day participants ate and behaved normally (except caffeine and alcohol), then arrived to lab just before bedtime.
2)They went to bed in a dark, quiet room.
3)The participant went to sleep with 2+electrodes attached beside the eyes (EOGs) and on scalp (EEG), which were fed to the experimenters room.
4)EEG wires became a ponytail/single cord to stop entanglement
5) The EEG was run continuously through night (at speeds of 3 or 6 mm per sec).
6)Participants woken by doorbell sound (placed near bed) in REM/NREM, or were randomly woken 5 or 15 mins after REM began.
7) Participants were asked if they dreamt or not
8) Asked to detailedly recall dream if they had one-by speaking into recording device connected to experimenters room.
9) Occasionally the experimenter would enter and ask more qs.
10)Initially, participants were asked to estimate length of time in REM sleep to nearest minute.
11) In revised procedure. participants were given a fixed choice of 5/15 mins to choose from.
12) They recorder their dreams into a tape recorder, sometimes being asked qs.
SAMPLE
-9 adult participants-predomenantly male (7m vs 2f)- 4/9 dropped out
-5 main participants studied intensely vs 4 others to compare : spending between 6 and 17 nights at lab.
-Other 4 were used to confirm results of the main pps, spending onlu 1-2 lab nights
-All pps in study identified by initials
-Researchers did not provide info about how pps were recruited or selected, nor mentioned any specific demographic details beyond gender.
EACH PARTICIPANT EXPERIENCED ALL EXP. CONDITIONS (repeated measures design).
PROCEDURE CONTINUED
-same procedure used when experimenter wanted to wake P from NREM sleep
-An invesigator was listening outside the room and occasionally enteres to further question on particular point in dream.
-Pps usually fell back asleep withing 5 mins
The 9 subjects were studied over a total of 61 nights with a total of 351 awakenings which averaged to…
5.7 awakenings per night.
DATA/MEASURES
Quantitative
-instances of dream recall, dream length estimaes and num of words in each dream narrative.
Qualitative
-descriptions of dreams
Results/HT 1
There is a relationship between REM (rapid eye movement) sleep and dreaming. They posited that most dreams occur during REM sleep.
-For all pps there was a high incidence of dream recall during REM periods (152 dreams/90%) and a low incidence during NREM periods (11 dreams/7%)
-individual differences with recall
-if pps were awoken during sleep they were sometimes rather bewildered and reported that they must have been dreaming but couldn’t remember it
-They recalled a mood, such as anxiety/pleasantness but no context
-led to assumption that dreams also occcur during NREM periods, just less vividly and possibly less often.
Results/HT 2
The duration of the dream correlates with the duration of the REM sleep period. They expected that longer REM periods would correspond to longer reported dreams-Length of REM periods and subjective dream duration:
-the estimates of duration dreams were fairly accurate
-when woken after 5mins, 45/5
1 estimations were correct
-after 15mins, 47 estimations/60 were correct
Results/HT 3 (eye movement pattern)
Type of eye movement and content of dreams reported by participants:
-mainly vertical (3 such dreams reported): standing at bottom of cliff, looking up at climbers, or looking down to pick up a ball and then back up to shoot it
-mainly horizontal (1): 2 people throwing tomatoes at one another
-Both h and v (10): looking at close things, talking with one another in a group, or fighting
-Little to no movement (21): watching something distant/fixed object in a field afar, driving a car…
Results/HT 4
Participants would be able to accurately recall their dreams if woken during REM sleep, but not during non-REM sleep. They anticipated higher dream recall during REM awakenings.
There was addittionally a significant positive correlation between REM length and lengths of dream narratives (number of words used).
Conclusions A
-Dreams are more likely to occur in REM sleep
-Dreams do not occur instantly/rapidly as had previously been suggested, they seem to occur at a rate similar to a real experience of the same sort in dream (ie real time)
Conclusions B
-Dream content appears to correspond to the direction in which eyes move
-It seems reasonable to conclude that an objective measurement of dreaming can be accomplished by recording REMs during sleep
Evaluation A
-Lab exps control extraneous variables
-loud doorbell sound to wake pps-avoid forgetting dreams once awake (standardized)
-pps not told about EEG pattern or wether their eyes moved or not-avoids demand charasteristics
-Correlation used-positive between REM duration nd number of words in narative, BUT only demonstrates link.
-To explore more this connection they compared 5 and 15mins in REM periods.
