Dement and Klietman

Dement and Kleitman

The relation of eye movements during sleep to dream activity: An objective method for the study of dreaming

Internal Validity

How well an experiment controls for confounding variables. The researcher is confident that it is the IV that is affecting the DV and no confounding variables are having an impact on the results.

Rapid Eye Movement Sleep (REM)

A stage of sleep in which our eyes move rapidly under the lids, is associated with vivid, usual dreams

Non-rapid eye movement sleep (nREM)

The stages of sleep (1-4) in which our eyes are still

Eye-movement-patterns

The patterns that most people tend to follow when looking at, for example, a menu. This can be helpful in designing menus

EEG (Electroencephalogram)

A machine used to detect and record electrical activity in nerve and muscle cells when many are active at the same time. It uses macro-electrodes, which are large electrodes stuck to the skin or SCALP next to eyes

EMG

Measures electrical activity of muscles

EOG

Measures eye movement

Dement and Kleitman aim

To investigate dreaming in an OBJECTIVE way by looking for relationships with eye movements in sleep and dreamer’s recall

D&K Study #1 Aim

Does dream recall differ between REM and nREM stages of sleep?

D&K Study #2 aim

Is there a positive correlation between subjective estimates of dream duration and the actual length of the REM period?

D&K Study #3 aim

Are eye movement patterns related to dream content?

D&K Study #1

P’s were woken either in REM or nREM, but not told which stages of sleep they had been in prior to waking. Confirmed if they had a dream. If so, P described dream content into a tape recorder.

D&K Study #1 IV

REM and nREM sleep

D&K Study #1 DV

Whether a dream was reported (if so, the details)

D&K Study #2

P’s were woken following either 5 or 15 minutes in REM sleep. Asked to choose whether they thought they had been dreaming for 5 or 15 minutes. In addition, report was given of dream content & the # of words in the dream narrative was counted.

D&K Study #2 IV

Waking after 5 or 15 minutes

D&K Study #2 DV

P’s choice of 5 or 15 minutes

D&K Study #3

The direction of eye movements was detected using electrodes around the eyes (EOG) P’s were woken after exhibiting a single eye movements pattern for longer than one minute. Again, asked to report dream content.

D&K Study #3 IV

Eye-movement patterns (D&K couldn’t manipulate this)

D&K Study #3 DV

Report of dream content

Repeated Measurers Design (D&K)

All P’s slept and were woken at various points (in REM or nREM or after 5 or 15 minutes)

D&K Materials

-sleep lab at university of Chicago

-EEG machine

-electrodes, gathered at top of P’s head into a single cord

-doorbell, used to wake up P’s

-Tape recorder, used to record P’s recollection of their dream content

Participants in D&K

9 adult participants were used in this study

Males used in D&K

7

Females used in D&K

2

People studied in detail in D&K

5

People used to confirm data obtained in D&K

4

PM & KC (initial for D&K)

Random waking’s to eliminate any possibility of an unintentional pattern

WD (D&K initial)

Treated the same way, but was told he would be woken only from REM sleep

DN (D&K initial)

Woken in repeating patterns of 3 REM followed by 3 nREM awakenings

IR (D&K initials)

woken from REM or nREM was chosen by the experimenter

D&K Results Study #1

P’s described dreams often when woken in REM, but rarely from nREM

D&K results study #2

When asked if they had been in REM sleep for 5 or 15 minutes, P’s responded with 88% and 78% accuracy. DN frequently found he could recall only the end of his dream, so it seemed shorter than it actually was.

Vertical Eye movements

3 of 9 P’s dreamed about standing at the door of a tall cliff, using a hoist. The P reported looking up at climbers at various levels and down the hoist

Horizontal eye movements

A single dream followed predominantly this movement. Dreamed about 2 people throwing tomatoes at each other

Little/no eye movement

On 10 occasions, P’s were woken. Reported watching something in the distance or fixated on a single object.

Mixed Eye movement

21 awakenings where the P reported looking at people or objects nearby. Ex. People fighting or talking to a group of other people.

D&K Study #1 Conclusion

Dreams probably (although not certainty) occur only during REM sleep. Dreams reported when woken from nREM sleep are ones from previous REM episodes.

D&K Study #2 Conclusion

The finding that the length of an REM period and its estimation by the P are very similar shows that dream are not instantaneous events, but rather they are experienced in “real time.”

D&K Study #3 Conclusion

Eye movements during REM sleep correspond to where, and at what, the dreamer is looking at in the dream. This suggests that the eye movements are directly related to dream imagery

Research method (main)- Natural lab experiment, others are observations, interviews, and correlation

D&K Research method

D&K protection from harm

As the P’s were sleeping in an unnatural situation it may have altered their normal sleep patterns. The person’s ability to concentrate at work or home next day may have been affected. There was no chance to ensure a normal sleeping night before the study ended.

D&K Confidentiality

The researcher only used P’s initials when publishing the data to ensure that specific dreams could not be linked to individuals.

D&K Application to everyday life

-The study could identify when P’s enter 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 lab and be wired up to an EEG

-the person’s brain wave patterns could be monitored to see whether they were typical or atypical

D&K Nature

It’s believed that the experiences of REM and nREM sleep are universal and therefore due to nature. All participants in the study experienced both types of sleep and also the majority of dreaming took place during REM sleep.

D&K Nurture

Environment factors can also affect sleeping patterns. Individual differences between P’s and this could be as a response to the environment as some of the P’s had very disturbed sleep, possibly due to the uncomfortably environment of the sleep lab