Dement, W., & Kleitman, N. (1957). The relation of eye movements during sleep to dream activity: an objective method for the study of dreaming.Journal of Experimental Psychology, 53(5), 339.AimDement and Kleitman’s research aimed to find objective methods to demonstrate a relationship between dream content and physiological indicators of dreaming, such as eye movements.Specifically, they wanted to investigate:Does dream recall differ between eye movement (REM) and quiescent (nREM) stages of sleepIs there a positive correlation between subjective estimates of dream duration and the length of the REM period before waking?Are eye movement patterns related to dream content?BackgroundAserinsky and Kleitman’s 1955 studyrevealed that participants who were woken from REM sleep were more likely to report vivid, visual dreams than those woken from non-REM sleep.Their research demonstrated that sleep consists of several alternating stages, including REM and non-REM periods.This groundbreaking work established the link between REM sleep and dreaming, while also revealing the cyclic nature of sleep stages, laying the foundation for modern sleep science.
Dement, W., & Kleitman, N. (1957). The relation of eye movements during sleep to dream activity: an objective method for the study of dreaming.Journal of Experimental Psychology, 53(5), 339.
AimDement and Kleitman’s research aimed to find objective methods to demonstrate a relationship between dream content and physiological indicators of dreaming, such as eye movements.Specifically, they wanted to investigate:Does dream recall differ between eye movement (REM) and quiescent (nREM) stages of sleepIs there a positive correlation between subjective estimates of dream duration and the length of the REM period before waking?Are eye movement patterns related to dream content?BackgroundAserinsky and Kleitman’s 1955 studyrevealed that participants who were woken from REM sleep were more likely to report vivid, visual dreams than those woken from non-REM sleep.Their research demonstrated that sleep consists of several alternating stages, including REM and non-REM periods.This groundbreaking work established the link between REM sleep and dreaming, while also revealing the cyclic nature of sleep stages, laying the foundation for modern sleep science.
Aim
Dement and Kleitman’s research aimed to find objective methods to demonstrate a relationship between dream content and physiological indicators of dreaming, such as eye movements.
Specifically, they wanted to investigate:
Background
Aserinsky and Kleitman’s 1955 studyrevealed that participants who were woken from REM sleep were more likely to report vivid, visual dreams than those woken from non-REM sleep.
Their research demonstrated that sleep consists of several alternating stages, including REM and non-REM periods.
This groundbreaking work established the link between REM sleep and dreaming, while also revealing the cyclic nature of sleep stages, laying the foundation for modern sleep science.
Psychology Being Investigated
Procedure
Dement and Kleitman (1957) is a classic study that explored sleep and dreaming using electronic recording, observation, and diary methods.
Sample
Each participant experienced all conditions of the experiment (repeated measures experimental design).
IV 1: Sleep Stage of Awakening
IV 2: Duration of REM Sleep
FindingsDV 1: Dream Recall & ContentThere were many more instances of dream recall in REM (1 mark) compared to instances of no recall/recall in NREM.Participants frequently described dreams when woken in REM but rarely did from nREM sleep (although there were some individual differences), and these differences were marked at the end of the nREM period (within 8 minutes of cessation of REM – only 6 dreams recalled in 132 awakenings). In nREM awakenings, participants tended to describe feelings but not specific dream content.
Findings
DV 1: Dream Recall & Content
There were many more instances of dream recall in REM (1 mark) compared to instances of no recall/recall in NREM.
Participants frequently described dreams when woken in REM but rarely did from nREM sleep (although there were some individual differences), and these differences were marked at the end of the nREM period (within 8 minutes of cessation of REM – only 6 dreams recalled in 132 awakenings). In nREM awakenings, participants tended to describe feelings but not specific dream content.
High incidence of dream recall during REM periods (152 out of 191 awakenings) compared to nREM periods (11 out of 160 awakenings)
When woken in nREM participants returned to nREM, but when woken in REM they typically didn’t dream again until the next REM phase (except sometimes in the final REM phase).
DV 2: Duration Estimate of REM Sleep & Dream Narrative Length
The accuracy of estimation of 5 or 15 minutes of REM was very high (88% and 78%, respectively). REM duration and the number of words in the narrative were significantly positively correlated.
Participants could distinguish between shorter and longer dream durations with considerable accuracy.
Significant positive correlations between REM period duration and dream narrative length for all participants (r ranging from 0.40 to 0.71)
The study found strong correlations between eye movement patterns during REM sleep and dream content.
These results suggest that eye movements during REM sleep reflect the dreamer’s gaze within the dream, supporting a direct link between physiological activity and subjective dream experiences.
Vertical movementscorresponded to vertical dream imagery (3 instances). Dreams involved predominant action in the vertical plane:Standing at the bottom of a cliff (1 mark) operating some sort of hoist machine (1 mark)Climbing a set of ladders (1 mark) looking up and down as they did (1 mark)One participant reported seeing themselves throwing basketballs at a hoop (1 mark). They saw themselves looking up at the hoop and then downwards to pick up another ball (1 mark)Horizontal movementsto horizontal imagery (1 instance). Dreams involved predominant action in the horizontal plane:Watching two people (1 mark) throwing tomatoes at each other (1 mark)Mixed movementsto close-up, varied experiences (both vertical and horizontal) corresponded to looking at things close to the dreamer (21 instances):Talking to a group of people (1 mark) standing close to them (1 mark)Searching for objects (1 mark) close to them (1 mark)Fighting with someone (1 mark) close to them (1 mark)Little or no eye movementcorresponded to fixed or distant imagery (10 instances):Watching something (1 mark) at a distance (1 mark)Staring fixedly at some object (1 mark) in the distance (1 mark)
Vertical movementscorresponded to vertical dream imagery (3 instances). Dreams involved predominant action in the vertical plane:
Horizontal movementsto horizontal imagery (1 instance). Dreams involved predominant action in the horizontal plane:
Mixed movementsto close-up, varied experiences (both vertical and horizontal) corresponded to looking at things close to the dreamer (21 instances):
Little or no eye movementcorresponded to fixed or distant imagery (10 instances):
Conclusions
Strengths
Objective quantitative data
Similarly, they calculated the percentage of accuracy of their dream duration estimates when awoken from either 5-minute or 15-minutes of sleep.
This helped researchers objectively compare in which stage of sleep participants reported a greater recall of dreams.
Likewise, they objectively compared when their accuracy of dream duration estimates between the two durations of awakenings was better, without any bias. This increased the internal validity of findings.
High level of control
These measures enhance the validity and reliability of the results.
The study usedelectroencephalography(EEG) to measure brain activity and this allows precise measurements to be taken.
Standardisation (Controls)
Another strength of the study was the use of a highly controlled procedure.
Researchers took care to maintain a quiet and dark room as participants slept to prevent their normal pattern of sleep from being disrupted in the laboratory.
They also asked participants to eat normally but avoid consuming caffeine and alcohol for the same reason.
These and other controls ensured that any dream-related activity of participants could be attributed only to the stages of sleep they were in and not to uncontrolled variables like the influence of alcohol or coffee, etc. that created disruption in sleep.
This also increased theinternal validityof findings.
Replicable
The reliability of Dement and Kleitman’s (1957) study, in terms of its replicability, is generally considered to be high due to several factors:
High external validity:Inclusion of waking validation study to support findings
To enhance theexternal validityof the findings on eye movement patterns during REM sleep, researchers conducted an additional study.
They asked 20 naive participants and 5 experimental subjects to observe distant and close-up activity while awake, recording their eye movements: horizontal, vertical, or mixed.
The patterns observed in this waking state were comparable to those during sleep, strengthening the study’s conclusions.
Weaknesses
Low generalisability
The sample was very small. The results cannot be generalised to the wider population because only 9 people were studied,
Only nine participants were studied in total and only five of these were studied intensively. This is a very small number of participants to generalize from.
You could argue that physiological processes are likely to be the same in all people but this may not be the case. There was no diversity in age, ethnicity and sex.
That is, it is possible that given their specific sleep patterns, they would largely experience dreaming in the REM stage of sleep and not other people with other sleep patterns. This reduces the population validity of the findings.
Small number of observations for each eye movement pattern
The study reported only 3 instances of vertical eye movements, 1 instance of horizontal movements, 21 instances of mixed movements, and 10 instances of little or no movement.
This small sample size for each pattern limits the generalizability of the findings.
It increases the possibility that the observed correlations between eye movements and dream content could be due to chance or individual differences.
A larger number of observations for each pattern would provide more robust and reliable results.
Low ecological validity
The research studied participants who went to sleep in a laboratory with electrodes stuck to their heads. It is unlikely that this bears much relation to sleep in a normal environment!
It is possible that being in such an artificial condition meant that their sleep was disturbed, and if this was the case, the researchers would not have been studying normal sleep patterns.
The participants were also woken up several times during the night and asked about their dreams. Again, this is unlikely to happen normally and may have had an effect on the way the participants slept.
However, research conducted outside of the controlled conditions of the laboratory would have been unable to measure brain activity and eye movements in the ways.
Difficulty in precisely matching eye movements to specific dream content
Dreams can involve complex and rapidly changing scenes, making it challenging to definitively link specific eye movements to particular dream elements.
The temporal resolution of awakening (after 1 minute of a pattern) may not capture the full complexity of eye movements during a dream sequence.
Individual differences in how people visually experience or recall dreams could affect the accuracy of matching eye movements to content.
The study doesn’t account for potential symbolic or abstract visual experiences in dreams that might not directly correspond to eye movements.
Demand Characteristics: Potential for retrospective bias in dream reports
Participants were awakened and asked to report their dreams after the fact, which can lead to retrospective bias.
Memory of dreams can fade quickly upon waking, potentially leading to incomplete or inaccurate recall.
Participants might unintentionally fill in gaps in their memory or alter details based on expectations or suggestions.
The act of waking up and reporting could itself influence the recalled content of the dream.
There’s a possibility of demand characteristics, where participants might report what they think the researchers want to hear.
Was the study useful?
Many other researchers have replicated Dement and Kleitman’s conclusions. However, one methodological issue should be considered.
Regarding the first research question, Dement and Kleitman conclude that dreaming occurs in REM rather than non-REM sleep.
What they have actually demonstrated is that dreams are recalled more often from REM rather than non-REM sleep and it may be that dreaming does occur in non-REM sleep, and it is much harder to recall them.
When the research was first conducted, very little was known about the relationship between eye movements and dreaming and so Dement and Kleitman’s research really did add new information to what was known about sleep. It is difficult, nearly fifty years later, to understand what a major breakthrough this study represented.
The use of EEG to record brain activity whilst sleeping was also relatively new, and it was not until research like this Core Study that it became clear that dreams could be studied in an objective way.
Dement and Kleitman’s research generated very many other studies into sleep and dreaming and there have been many useful findings.
Issues and Debates
The application of psychology to everyday life
The EEG can detect REM/NREM sleep stages, which can be useful in diagnosing sleep-related problems. This information can then be used to develop appropriate treatments for sleep disorders.
For people with sleep disorders, the EEG’s ability to detect REM/NREM sleep is particularly valuable. A psychologist can analyze the EEG output to compare the patient’s sleep patterns with those of a ‘normal’ sleeper, helping to identify specific abnormalities in the sleep cycle.
Nature versus nurture
The study leans towards a biological explanation of dreaming, emphasizing the role of natural physiological processes (REM sleep, eye movements).
Reductionism versus holism
The approach is somewhat reductionist, breaking down the complex experience of dreaming into measurable physiological components (eye movements, EEG patterns).
Determinism versus free-will
The strong correlation between eye movements and dream content suggests a degree of physiological determinism in the dreaming process.
However, the variability in dream content and recall also leaves room for individual differences and possibly some element of “choice” in dream experiences.
Individual and situational explanations
The study considers both individual differences (e.g., variation in dream recall ability) and situational factors (e.g., time of night, duration of REM sleep).
Idiographic versus nomothetic
The study combines nomothetic elements (looking for general patterns across participants) with idiographic aspects (detailed analysis of individual dream reports).
This balance allows for both general conclusions about dreaming and recognition of individual variations.
Past Paper Question(Cambridge Exam)
Dement and Kleitman (sleep and dreams) collected quantitative and qualitative data.Outlineonequantitative result from the ‘dream-duration estimates’. You must use data in your answer. [2]Outlineonequalitative results from the dream contents reports. [2]
Evaluate the Dement and Kleitman (sleep and dreams) study in terms oftwostrengths andtwoweaknesses. At least one of your evaluation points must be about the use of quantitative data. [10]
Dement and Kleitman (sleep and dreams) collected quantitative and qualitative data.Outlineonequantitative result from the ‘dream-duration estimates’. You must use data in your answer. [2]Outlineonequalitative results from the dream contents reports. [2]
From the dream-duration estimate part of the study:State how Dement and Kleitman chose whether to wake a participant after 5 minutes or after 15 minutes of REM sleep. [1]Describe the dream-duration estimates for the participant DN whose responses did not follow the same pattern as others. [2]Outlineonestrength of the study. [2]
From the dream-duration estimate part of the study:State how Dement and Kleitman chose whether to wake a participant after 5 minutes or after 15 minutes of REM sleep. [1]Describe the dream-duration estimates for the participant DN whose responses did not follow the same pattern as others. [2]Outlineonestrength of the study. [2]
Saul McLeod, PhD
BSc (Hons) Psychology, MRes, PhD, University of Manchester
Saul McLeod, PhD., is a qualified psychology teacher with over 18 years of experience in further and higher education. He has been published in peer-reviewed journals, including the Journal of Clinical Psychology.
Olivia Guy-Evans, MSc
BSc (Hons) Psychology, MSc Psychology of Education
Olivia Guy-Evans is a writer and associate editor for Simply Psychology. She has previously worked in healthcare and educational sectors.
Julia RusselHead of PsychologyBSc (Hons), PsychologyJulia Russell has over 25 years experience as a Psychology teacher. She is currently Head of Psychology at The Queen’s School, Chester. She is Principal Examiner for two major awarding bodies, visiting tutor at Wrexham Glyndŵr University and an established author.
Julia RusselHead of PsychologyBSc (Hons), Psychology
Julia Russel
Head of Psychology
BSc (Hons), Psychology
Julia Russell has over 25 years experience as a Psychology teacher. She is currently Head of Psychology at The Queen’s School, Chester. She is Principal Examiner for two major awarding bodies, visiting tutor at Wrexham Glyndŵr University and an established author.
