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Dement and Kleitman - REM and Dreaming

Core Study 4

Rajiv Ariaraj

on 4 November 2014

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Transcript of Dement and Kleitman - REM and Dreaming

Core Study: 5
The Relation of Eye Movements during sleep to dream activity: an objective method for the study of dreaming.
P’s were woken either 5 or 15 minutes after REM sleep began.
They were then asked to estimate the length of their dream by choosing either 5 or 15 mins.
Is there a correlation between the estimate of dream length and time spent in REM?
The Physiological Approach
In pairs:
Research Method
P’s were woken one minute after distinct patterns of eye movement had occurred as measured by the electrodes around the eyes:

Patterns were: mainly vertical, mainly horizontal, both V&H or no eye movement.

P’s were asked to record what they had been dreaming about.
Will the direction the eyes are moving in be related to the content of the dream?
Charles Whitman

Dement and Kleitman (1957)
investigated what happens when we sleep

Sperry (1968)
investigated the behaviour and experiences of people who have had their brains separated into two halves

Maguire (2000)
investigated whether there are navigation-related structural changes in the hippocampi of taxi drivers
The 3 Physiological Studies
Is one of the oldest types of measurement for brain activity.

there are various types
Studying the Brain
Phineas Gage
At various times during the night (some during REM, some during non REM) P’s were woken by a doorbell.

They were instructed to immediately record whether they had been dreaming or not (a yes or no question).

P’s were not told whether they had been in REM or Non REM sleep
Does dream recall correlate with periods of REM sleep?
The Brain
The most complex organ in your body, and the one which fascinates many researchers, the brain can be seen as a “biological machine” that controls our behaviour.
The Physiological Approach to psychology looks at how biological factors can affect our behaviour
A person has many biological factors within them.
To Psychology
main assumption
of the Physiological Approach psychology is:
"Our behaviour is caused by our physiology (or biology)"
Thoughts and feelings all have a physiological cause.
We need to study the brain and other biological systems to understand human behaviour.
How is this different from the social approach?
Movement, orientation
Visual processing
Auditory and speech processing
Thinking, reasoning, problem solving
Each part of your brain has a different role.
How do we know our physiology determines our behaviour?
Psychological Disorders
Bi-polar disorder
Stroke Victims
How could we study
someone’s brain?
See what ideas you
and the person next
to you can come up with
Twin studies can tell us whether having the same or different genetics has an impact on behaviour
CAT scans
PET scans
MRI scans
Some show the structures in the brain
Others show the activity levels
Brain scans
or, EEG for short.
Electrodes are attached to the scalp and measure the brain’s electrical impulses (brain activity)
The three studies we will look at over the next few weeks are:
Results and Conclusion
What happens when we sleep?
We are not awake one second
and completely asleep another.
Sleep is a process that takes
several STAGES.
Researchers used to think that our brain "switched off" when we slept, however results from the EEG of the brain shows significant activity while we are sleep.
There are 2 types of sleep that the EEG has discovered and you need to know about.
(Rapid Eye Movement)
(Non Rapid Eye Movement)
NREM is the first type of sleep that we enter. It is divided into 4 stages. Each takes around 20 minutes or so.
1. You are in your bed, and falling asleep. Your brain waves are slowing down and becoming longer, rather than short and fast. You are still aware of the world.
2. This is the beginning of "true sleep" your brain is getting even slower. However, you might experience and suddenly feel hypnagogic hallucinations.
3 and 4. The deepest, slow wave sleep. Your body still might move (e.g. roll in your bed) but you are pretty much unaware of the world. Stage 4 is the stage where most sleep walking will occur.
After you have finished stage 4 of NREM, your body then moves onto REM sleep.
What does REM sleep most look like according to the EEG?
The arrival of REM sleep was surprising to researchers when they first discovered it, as the EEG showed that the participant was displaying similar brain activity to being awake.
REM sleep is characterised by several different physiological changes in the body.
1. Eyes begin to dart back and forth under the eye lids.
2. A complete lack of muscle tone, and a lack of movement suggests that the body is paralyzed.
3. Brain waves are fast, resembling the awake stage.
After your REM sleep is finished, your body moves back into stage 1 NREM.
REM Sleep gets longer the night goes on.
Sleep Disorders
Sleep Walking
Night Terrors
Sleep Talking
Sleep Paralysis
Tends to occur in younger children.
Happens during NREM sleep (the body is paralysed in REM).
Low consciousness in the mind conducts activities associated with full consciousness.
Similar to sleep walking.
It can occur during the transitions between the stages of NREM sleep.
Most people can awaken very briefly between stages but some show behaviours like talking/ walking/ cooking.
Occurs in the first third of the night.
No need to wake up people during this, there is no benefit to it and it can be quite traumatic for the person.
Characterised by screaming and thrashing around suddenly in bed.
Tends to happen in children.
They are not nightmares, but tend to occur inbetween stages of sleep.
Often the person will not have any memory of the night terror afterwards and is usually more traumatic for the person witnessing it.
Sleep paralysis occurs during a disrupted REM sleep cycle.
The mechanism in the brain responsible for paralysing your muscles is out of sync with your conscious mind.
This can result in waking up, but being completely paralysed for a few minutes until your brain catches up.
Dement and Kleitman (1957)
To investigate if there was any association between REM sleep and dreaming.
3 Research questions:
Does dream recall correlate with periods of REM sleep?

Is there a correlation between the estimate of dream length and time spent in REM?

Will the direction the eyes are moving in be related to the content of the dream? (what they are dreaming about)
What is the IV and DV for each of these?
9 Adults
7 Males
2 Females
5 Studied Intensively, 4 to Confirm Findings.
Participants arrive at the lab just before their usual bedtime.
They had been told to eat normally,
but stay away from ALCOHOL and CAFFEINE.
Dement and Kleitman wanted to measure each participants physiological changes during sleep.
They did so in 3 ways:
Electrical Impulses
Eye Movements
Muscle Tone
At various points in the night,
participants were woken in the sleep lab by a doorbell, and were then asked to speak into a microphone about their dreams. The researcher did not enter the room unless necessary.
Participants were woken an average of 5.7 times a night and slept for 6 hours.
Research Question 1
Research Question 2
Research Question 3
Research Questions
No alcohol or caffeine
Doorbell used to wake
Tape recorder to record participants
Tested individually
No contact with experimenter (avoids bias)
Same sleep lab used
Same measurements used to monitor participants
Electrodes were placed to the participants' face and scalp.
They then went to sleep in a darkened room. All participants slept in the same room, but they were tested individually.
HOMEWORK: start a new folder, for the rest of the studies. You will need a slightly larger folder (a lever arch?) we have only covered 3 of 15 studies.

SOCIAL APPROACH PACK - Attach it to you folder and bring it in. If you can't find it, you MUST let me know so I can give you a new one. I'll ask to see them with you next lesson.
1.People who become blind after birth can see images in their dreams.

2. We only dream about people/things that we have seen before.

3. We become paralysed during sleep.

4. If you die in your dream, you die in real life.

5. You need less sleep as you get older.

6. Alcohol makes you sleep better

7. Some people can still function effectively with only 5 hours of sleep
True or False?
8. Insomniacs don’t sleep at all.

9. If you get too much sleep in the night, you feel tired in the morning.

10. Dolphins do not sleep.

11. Cows can sleep standing up.

12. It is possible to sleep with your eyes open.

13. Frankenstein was created after being dreamt by Mary Shelley in 1816.

Fill out the first 3 boxes in the pack.
Complete pages 1 and 2 of your pack.
What controls were used in the study?
Does dream recall correlate with periods of REM sleep?
Research Question 1
Is there a correlation between the estimate of dream length and time spent in REM?
Will the direction the eyes are moving in be related to the content of the dream?
Research Question 2
Question 3
More dreams were reported in REM than Non REM.
When no dream recall was recorded in REM this tended to be in the earlier periods of the night.
NREM dreams were usually within 8 minutes of REM sleep.
Mostly correct- suggests dreams are in ‘real-time’.
However, the more wrong estimates after 15 mins suggests that the longer they had been in REM the less accurate they were in estimating dream length.
There was a significant relationship between the number of words in the P’s dream narrative & amount of time in REM.
The results suggested that eye movements were related to dream content, indicating that eyes are moving as if seeing what the P’s are dreaming about.
Type of eye
Example of dream content
Vertical and Horizontal
Little or no movement
Climbing ladders,
Looking up a cliff
Watching people throw tomatoes at each other
Talking to groups of people, looking for something
Staring at an object, driving and staring at the road ahead
Dement and Kleitman concluded that there is a strong connection between REM sleep & dreaming...
...BUT it cannot be stated that dreaming did not occur at other times during sleep.
Dreams appear to be in ‘real-time’ due to the high accuracy of estimated REM sleep length.
Eye movements appear to represent the content of dreams.
A neurological disorder that results in the brains inability to effectively regulate sleep-wake cycles.
It can cause excessive sleepiness and daytime sleep "attacks".
A very strong urge to sleep, followed by a 15 minute nap.
What type of research method is Dement and Kleitman's study?
A Lab Experiment
Highly controlled environment
Manipulated IV (when woken)
Measured DV (Dream Reports)
Identify factors which make this study high in ecological validity and low ecological validity.

Then comment on the 6 ethical issues.

Consider the questions on the reliability and validity of this study.
Identify TWO problems of Dement and Kleitman’s study.
Consider what you could do to improve on these factors.
In pairs:
(does your dream last the length of your REM sleep?)
(Do you dream when you are in REM Sleep?)
(Do your eyes move in your sleep the way they move in your dreams?)
It is much more likely that participants would recall dreams in REM sleep than NREM.
Anomalous Findings?
Why were some dreams (11) reported during NREM sleep?
When awoken from NREM sleep, participants were bewildered and would report dreaming, but could not remember what the dream was about.

Sometimes they could remember feelings (happiness, anxiety) but still could not report what the dream was about.
How would you test each of the research questions?
Can you predict what Dement and Kleitman did?
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