Dement and Kleitman research (1957)

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

Dement and Kleitman aimed to provide a more detailed investigation of how the objective / physiological aspects of rapid eye movement relate to the subjective experience of dreaming.

There is a significant association between REM and reported dreaming.

There is a significant positive correlation between the length of time spent in REM sleep and the duration of dreaming.

There is a relationship between the pattern of eye movements and the reported content of the dream.

Design : Laboratoty eperimentation and observation

Subjects: 9 adult participants (7male and  2 female) from the Chicago area of America.
Five of the participants were studied intensively and the other four were used to confirm the findings

Each participant reported to lab just before usual bedtime for a polysomnography.
They were to told to avoid caffeine or alcohol during the day.
Electrodes attached to head and faces.
Participants slept individually in a quiet dark room.
EEG continuously recorded brain activity.

Participants were woken several times during the night by the researchers and they were asked to speak immediately into a tape recorder about their dreams.

Participants were woken up after being in REM for either 5 or 15 minutes and were asked to state how long they had been dreaming for.

Participants were woken up after one of four eye movement patterns occurred :

1. Vertical
2. Horizontal
3. Vertical and Horizontal
4. Little or no eye movement

There was no contact between researchers and participants during dream recall:

1. woken by doorbell
2. spoke into tape recorder

• REM periods were clearly observed and distinguished from non-REM periods, in all participants.
• It is most likely that REM sleep is the only time we dream.
  
• There was a strong association between the patterns of rapid eye movements and the content of dream reports.

• Ethical
• Strong evidence that REM sleep is a dream sleep

• Small sample - not representative
• Low ecological validity
• Possible ethnocentric bias (carried out only in US)
• The study can not be generalised to children