Review: Dement and Kleitman (Sleep and Dream)

Psychology Being Investigated / In the dream or rapid eye movement (REM) sleep stage, our eyes move under the lids.

In Aserinsky and Kleitman’s (1955) study, participants woken from this stage were more likely to report a vivid, visual dream than participants work from NREM sleep
It is possible to separate into 4 stages 1-lightest 4-deepest
REM sleep resembles wakefulness in some ways (eyes move we often experience vivid thoughts in the form of dreams, and our brains are active)
Different from wakefulness; we are quite difficult to wake up, we are fairly insensitive to external stimuli, and we are paralysed.

AIM / Overall AIM: to investigate dreaming in an objective way by looking for relationships between eye movements in sleep and the dreamer’s recall.

Specific AIMS:
To test whether dream recall differs between REM and nREM sleep.
To investigate whether there is a positive correlation between subjective estimate of dream duration and length of the REM period.
To test whether eye-movement patterns are related to dream content.

Hypothesis /

Dreams occur During REM Sleep
Dreams happen in real time and people can guess how long they have been dreaming
Eye movement patterns relate to dream content

Research Method/ Design / Natural Laboratory; observation, interviews, correlations
Repeated measures- each Ps tested in both conditions
Repeated Measures- participants take part in all conditions of the IV
Variables:
IV & DV / Study 1: Natural Experiment in a laboratory setting.

IV- REM Sleep/ nREM Sleep
DV- whether a dream was reported and, if so, the detail

Study 2: True Experiment- data was used in both experimental and correlational designs:
•IV were waking after 5 or 15 minutes
•DV was the participant’s choice of 5 or 15 minutes
Study 3: Natural experiment conducted in a laboratory
•IV- eye-movement pattern type (cannot be manipulated by the researchers
•DV- report of dream content
Sampling Method / Opportunity
Sample /

9 Adults- 7M & 2F

•5 Intensely Investigated for 6-17 nights
•50-77 awakenings
•4 TO confirm findings for 1-2 nights
•4-10 awakenings
•Each participant is identified with a set of initials
Procedure / Materials:
•SLEEP LAB @ UNIVERSITY OF CHICAGO
•EEG MACHINE TO MEASURE SLEEP OBJECTIVELY
•ELECTRODES WERE GATHERED AT THE TOP OF PS HEAD INTO A SINGLE CORD
•DOORBELL USED TO WAKE UP PS
•TAPE RECORDER USED TO RECORD PS RECOLLECTIONS OF WHAT THEY WERE DREAMING ABOUT

During the day prior to arrival: Ps were told to eat normally and to avoid alcohol and caffeine
Ps arrived at the laboratory just before their normal bedtime and were fitted with electrical recording apparatus.

•Electrodes near the eyes (to record eye movements) and on the scalp (to record brain waves)
•Once participants were in bed in a quiet, dark room, wires from the electrodes (which fed to the EEG in the experimenter’s room) were gathered into a pony tail from each participants head to allow the person freedom of movement.

EEG ran continuously throughout the night to monitor participants sleep stages and to inform the researchers when participants should be woken up
Ps were woken by a doorbell that was loud enough to wake from any sleep stage

•Researcher did not have to enter the room so they were all treated the same
•Doorbell was wrung at various points throughout the night and participants indicated:
•Whether they had been dreaming prior to being woken up
•If so describe the dream into the voice recorder
•Occasionally researcher entered the room after a Ps had finished speaking in order to ask questions
Study 1: Patterns for waking
•Patterns of Rem and nREMwakings differed between the participants. The Ps with the initials:
•PM and KC were determined randomly to eliminate any possibility of an unintentional pattern.
•WD was treated the same way, although he was told he would be woken only from dream sleep
•DN was woken in a repeating pattern of 3 REM followed by 3 nREM
•IR from REM and nREM was chosen by the researcher
Study 2:
•Ps were woken by a doorbell that was loud enough to wake from any sleep stage
•Researcher did not have to enter the room so they were all treated the same
•Doorbell was wrung at various points throughout the night and participants indicated:
•Whether they had been dreaming prior to being woken up
•If so describe the dream into the voice recorder
•Occasionally researcher entered the room after a Ps had finished speaking in order to ask questions.
•Estimate how long you have been dreaming either 5 or 15 minutes
Study 3:
•Ps were woken by a doorbell that was loud enough to wake from any sleep stage
•Researcher did not have to enter the room so they were all treated the same
•Doorbell was wrung after a single eye movement pattern had lasted for more than 1 minute.
•Mainly Vertical
•Mainly Horizontal
•Both Vertical and Horizontal
•Little to no eye movement
•Describe the dream into the voice recorder
•Occasionally researcher entered the room after a Ps had finished speaking in order to ask questions.
Data Collection /

Observation- which way was the eye moving
Observation of EEG machine read out
Interviews- Ps were asked to recall dream content
Correlation- EEG machine read out and Ps responses

Study 1:
•Quantitative- measured EEG patterns in REM and nREM
•Qualitative- Dream content
•Dream was only counted if there was a coherent fairly detailed description of the content
Study 2:
•Quantitative- EEG patterns in REM sleep and Ps estimated time of dreaming, number of words in the dream narrative
•Qualitative- Dream content
•Dream was only counted if there was a coherent fairly detailed description of the content
Study 3:
•Quantitative- EEG patterns in REM sleep
•Qualitative-
•Dream content- Dream was only counted if there was a coherent fairly detailed description of the content
•Observation- the movement of the eyes
Results / Question 1:
•REM- 79.6 (152/191) of awakenings produced dream recall
•nREM- 93% (149/160) of awakenings did not produce dream recall
•Participant WD was no less accurate even though he was misled to expect to be dreaming every time.
•Ps did not become more accurate with practice
•Participants frequently described dreams when woken from REM but rarely did from nREM

There were some individual differences

•When Ps were woken in nREM they described feelings rather than dreams
•Least likely to remember a dream if they were awoken during sleep stage 2- tended to be bewildered and report feelings such as anxiety, pleasantness and detachment
•When Ps were awoken closer to REM sleep (w/in 8 mins), they displayed better recall of dreams.
•Awakenings from REM sleep did not always produce dream recall, absence of dreaming in REM was more common early in the night
•39 REM awakenings when dreams were not reported, 19 occurred in the 1st 2 hours of sleep, 11-2nd 2 hours, 5 3rd 2 hours, 4 from the last 2.
•Awakenings from nREM always produced a low incidence of dream recall
Question 2:
•88% Accuracy for 5 minutes
•78% accuracy for 15 minutes
•DN frequently could only recall the end of the dream and therefore guessed 5 minutes more frequently and was wrong significantly more than others
•Initially researchers tried to wake Ps at various times of REM and Ps about duration, although answers were close, this was too difficult
•Instead researchers asked if they thought they were asleep for 5 or 15 minutes, Ps responded more accurately
•Results revealed that all but one of the participants were able to choose the correct dream duration fairly accurately (SEE DN)
•Correlations were found to be sig .40-.71 for each participant
•Findings show that we dream in relatively real time
•Using REM periods over a range of durations, narrative from 152 dreams were collected, 26 were not used because of recording quality (15-35 per participant
•Number of words in the dream narrative was counted.
•Even though they was affected by how expressive the participant was, a significant positive correlation was found between REM duration and # of words in the narrative
•Dream narratives for very long durations (30-50 min) were not much longer than those for 15 minutes, but participants did report the felt as though they had been dreaming for a long time and could not recall the beginning of the dream
Question 3:

This part of the study is based on 35 awakenings after the Ps had a specific eye movement
Periods of only vertical or only horizontal were rare
Vertical Eye movement- 3 dreams
Dreamer was standing at the bottom of a tall cliff operating a hoist and looking up at climbers, then down at levers
A man was climbing up a series of ladders, and looking down
Dreamer was throwing a basketball, looking at the net, shooting, then looking down for the next ball
Horizontal- 1 dream
Dreamer was watching 2 people throw tomatoes
Mixed Eye Movement- 21 awakenings
Ps reported looking at objects or people close to them.
Talking to a group of people, looking for something, fighting someone
Little to no movement- 10 dreams
All reported looking at something in the distance
2 had large eye movements to the left just a second or two before waking
Ps had been driving a car and staring at the road, approached a road junction and was startled by a speeding car suddenly appearing to his left (as the bell rang)
Ps was also driving a car and staring at the road, immediately before being woken he saw a man standing to his left and acknowledged him
Findings suggest that the eye movements of the subjects are related to the dream content
Indicated that the eyes were moving as if seeing what the P was dreaming about

Conclusion /

Dreams probably (although not certainly) occur during REM sleep, which occurs regularly throughout the night. Dreams recorded when woken from REM are ones from previous REM episodes. As REM is later in the night dreams are more likely to occur.
It is often believed that dreams happen in an instant. If the length of REM periods is proportional to subjective estimates, this would help to confirm that the two are related and would provide information about the rate at which dreaming progresses. Dreams happen in “real time”
Eye movements during REM sleep correspond to where, and at what, the dreamer is looking in the dream. This suggests that eye movements are not simply random events caused by the activation of the central nervous system during dream sleep, but are directly related to the dream imagery. Furthermore they correspond in amplitude and pattern to those we experience when awake

Evaluation: Generalizability / Strength

Both genders in the sample- there may be differences in dreaming between me and women

Weakness

Only 5 people were studied in detail with 4 more used to confirm these findings. The small sample size could make it difficult to generalize beyond the sample
These 5 + 4 people may not represent a wide cross section of society in terms of how we dream and what we dream about
Opportunity: Suffer from a lack of generalizability, researcher is unlikely to gain a wide variety of participants to allow generalization because this technique draws in one type of person

Evaluation: Reliability / High level of standardization and can be replicated to test reliability:

Standardised procedure- pre-study levels of caffeine and alcohol, the doorbell sound, the EEG monitoring.
Other researchers could easily replicate this study to test reliability

High level of control, researchers can be more confident it is the IV directly affecting the DV

High Control: all participants experienced the same conditions( see standardization) mean that for each part of the experiment, the researchers could confidently conclude cause and effect (dream recall is affected by stage of sleep)
Control for extraneous variables- If some Ps had woken slowly they would have forgotten their dream, avoided using a loud doorbell

Evaluation: Application to everyday life / See Useful
Evaluation: Useful /

The study could identify when participants ere entering REM or nREM sleep.
The EEG monitor that did this could help sleep scientists to identify whether a person has a disorder based around REM sleep. A person complaining of poor sleep could come into a sleep laboratory and be wired up to an EEG. The persons brain wave pattern could be monitored to see whether they were typical or a typical
The study was a generative one, it sparked new waves into sleep research
Subsequent studies have not supported D & K’s findings that there is a relationship between eye movements and what the person is dreaming about

Evaluation: Validity / Artificial setting; low ecological validity

In lab experiments participants take part in tasks that are nothing like real-life ones, so the tasks lack mundane realism
The task of being woken up and then asking to recall dream content or estimate dream length is not a normal activity for people to engage in.
Therefore study may lack mundane realism
Low Ecological Validity
Participants had to sleep in an unusual environment (a lab) with electrodes on their head (EEG monitor) which is, of course, an artificial setting for them.
Ps who usually drink coffee or alcohol could have experienced sleep or dreams that were not typical for them as they had been asked to refrain from those drinks
The definition of ‘dream’ was clearly operationalized, as a recollection that included content and not just an impression they had been dreaming- this helps to raise validity as D&K could be more sure the Ps was dreaming
At the beginning of the study Ps were asked to estimate how long they were dreaming but this was difficult (even though many were very close) so they changed it to 5 or 15 minutes- this increases validity as it reduced participant variables such as the ability to recall dreams

Evaluation: Ethics / Strengths

Confidentiality: Researchers only used Ps initials when publishing the data to ensure that specific dreams could not be linked to individuals

Weaknesses

Protection: As the Ps were sleeping in an unnatural situation it may have altered their normal sleeping patterns. The persons ability to concentrate at work or at home the next day could have been affected. There was no chance to ensure a normal sleeping night before the study ended.
Deception: Ps WD was misled about the stage of sleep he was being woken in. Deception can cause stress and means Ps cannot give informed consent

Debates: Individual v. Situational / N/A
Debates: Nature v. Nurture /

The study could be considered to be relevant to the nature v nurture debate as it is believed that the experience of REM and nREM sleep are universal and therefore due to nature
All participants in the study experienced both types of sleep and the majority of dreaming too place during REM, suggesting dreaming during REM is due to nature
However, there were individual differences between participants and this could be as a response to the environment as some of the participants had very disturbed sleep, possibly due to the uncomfortable environment of the sleep laboratory.
This shows that environmental factors can also affect sleeping patterns

Debates: Use of Children / N/A
Debates: Use of Animals / N/A