Dement and Kleitman (1957) Study

Aim

• General Aim: Investigate the relationship between eye movements and dreaming.
• Specific Aims:
  1. Does dream recall differ between REM and NREM stages of sleep?
  2. Is there a positive correlation between estimated dream duration and REM period length?
  3. Are eye movements related to dream content?

Research Hypothesis

1. Significant association between REM sleep and dreaming.
2. Positive correlation between estimated dream duration and REM period length.
3. Significant association between eye movement patterns and dream content.

Background

• Psychometrics Used:
  • EEG (Electroencephalogram): Traces brain activity changes during sleep.
  • EOG (Electrooculogram): Traces eye movements during sleep.
• Sleep Stages:
  • REM: Rapid Eye Movement, associated with dreaming.
  • NREM: Non-Rapid Eye Movement.
• Previous Research: Aserinsky (1955) found REM is linked to vivid, visual dreams.

Research Method

• Laboratory experiment with different methods to test each aim.

Research Design

• Approach 1: Natural experiment, repeated measures design.
  • IV: Waking from REM or NREM.
  • DV: Dream recall.
• Approach 2: True experiment with correlational study, repeated measures design.
  • IV: Waking after 5 or 15 minutes into REM.
  • DV: Estimated dream duration.
• Approach 3: Natural experiment, repeated measures design.
  • IV: Eye movement patterns.
  • DV: Dream content.

Sample

• 7 males and 2 females, recruited via opportunity sampling.
• 5 participants studied in detail, 4 used to confirm results.

Procedure

• Participants avoided caffeine and alcohol; slept in a dark, quiet room.
• Procedure 1: Woken to test dream recall during REM and NREM.
• Procedure 2: Woken after 5 or 15 minutes into REM to estimate dream duration.
• Procedure 3: Eye movement direction detected with EOG, participants reported dream content.

Results

• General Findings:
  • REM occurred every night, with individual variation.
  • Average time between dreams: 92 minutes.
  • Average REM length: 20 minutes.
• Results 1:
  • REM awakenings: 79.6% dream recall.
  • NREM awakenings: 7% dream recall.
• Results 2:
  • Accurate REM duration estimates: 88% for 5 mins, 78% for 15 mins.
  • Positive correlation between REM duration and dream narrative length.
• Results 3:
  • Eye movement patterns linked to dream content.

Conclusions

1. Dreams occur during REM sleep only.
2. Dream duration and REM period lengths are similar, indicating real-time dreams.
3. Eye movements correspond to dream content.

Strengths and Weaknesses

• Strengths:
  • High reliability due to controlled lab environment.
  • Avoided demand characteristics.
  • Included both genders, enhancing generalisability.
  • Collected both quantitative and qualitative data.
• Weaknesses:
  • Small sample size limits generalisability.
  • Deception caused potential distress.
  • Lacks ecological validity.

Nature vs. Nurture

• Dream content is influenced by nurture (experience), but the ability to dream is nature.