Dement and Kleitman (1957)

Dement and Kleitman (1957)

1. Key Terms

   • REM
     • Rapid eye movement
   • NREM
     • Non rapid eye movement
   • EEG
     • A way of measuring the electrical activity in the brain by using electrodes connected to the scalp
   • Correlation
     • The relationship between to variables.

2. Aim

   • To attempt to determine the relationship between eye movement and dreaming
   • There were 3 approaches:
     • Approach 1
       • To see whether ps were more likely to remember their dreams when woken during REM sleep
         • Will people be more likely to report dreams if they are woken during REM sleep than periods or NREM sleep?
     • Approach 2:
       • To see whether the ps were more likely to estimate how long they had been dreaming for and whether their estimates correlated with the length of time they had been in REM sleep
         • Can people accurately estimate the duration of their dreaming?
     • Approach 3:
       • To see whether the content of the dream showed a relation to the pattern of eye movement
         • Is the direction of eye movement during REM sleep related to dream content?

3. Procedure

   • Laboratory experiment
   • 7 males, 2 females all adults
     • Told to avoid caffeine and alcohol on the day of the experiment
     • Reported to the sleep lab just before their normal bedtime
       • Electrodes were attached near their eyes and scalp to measure eye movement and electrical activity in the brain
         • Attached to the EEG machine
       • Quiet dark room
       • At certain times during the night ps were woken by a doorbell
         • To test dream recall
           • Recorded into a tape recorder
           • They had to sate whether they had been dreaming and, if so their dream content

4. Findings

   • Question 1
     • All ps showed periods of REM
     • Length of REM increased the longer the ps was asleep
       • REM occurred at fairly regular intervals during the night
         • Average of the group was 93 minutes
       • More likely to have dream recall when woken in REM sleep
     • Eye movement were not constant during these periods
       • They happened in 'bursts of 1 or 2, up to 50 or 100 movements'
   • Question 2
     • Ps were mostly accurate with their estimation of dream length
   • Question 3
     • Most ps had periods of both vertical and horizontal eye movement
     • Results support the idea that eye movement is connected to dream content

5. Strengths

   • Conducted in a laboratory
     • High levels of control
   • The researchers were able to control many aspects of the experiment
     • Makes it easier to draw conclusions
   • The study used EGG machines which study brain activity
     • Allows for precise measurement to be taken

6. Weaknesses

   • The study was carried out in laboratory
     • This lacks ecological validity