Dement and Kleitman (1957)

Dement and Kleitman1957

AIM: To rigorously test the relation between eye movements and dreams

HYPOTHESES: 1. Participants who are woken during REM sleep are more likely to recall dreams. 2. Participants who are woken after 5 or 15 minutes will be able to say how long they have been dreaming. 3. Eye movements will link to the content of the recalled dream.  

PARTICIPANTS: Nine Adults - seven males and two females. Five studied intensively, with minimal data from the other four used to confirm findings from the five studied intensively

Laboratory experiment using a repeated measures design.

Independent Variables:1.Whether woken in REM or non-REM sleep 2.Whether woken after 5 or 15 minutes 3.Movement of eyes

Dependent Variables:1.Whether dream recalled 2.Estimate of length of dreaming 3.Content of dream

until 1950 people thought sleep was a passive activity for our brains

neurotransmitters control whether we are asleep or awake

PROCEDURE: Adults reported to sleep laboratory just before normal bedtime. No alcohol or caffeine. Electrodes were attached to record eye movement and brain waves. At various times during the night, participants were woken – some randomly, some in pattern, some at the whim of experimenter.

During sleep, we usually pass through five phases of sleep: stages 1, 2, 3, 4, and REM (rapid eye movement) sleep.

CONTROLS:There was no contact between experimenter and participants during dream recall. They were woken by a bell and they spoke into tape recorder. No caffeine or alcohol were allowed - both could affect REM sleep. Experimenter checked participants’ eye movements when awake to see eye movement when looking in the distance.

Study lacks ecological validity.   The situation in which the participants had to sleep was unusual and could have affected their sleep patterns.  Also the nature of the method of waking participants may have affected their ability to recall their dream.

The sample size was small and only included 2 females so we could argue that the results were biased towards the dream pattern of men rather than women.

method was very tightly controlled.  For example the researchers were able to control the location, sleeping time and the participants use of stimulants.

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