Dement & kleitman et al.

• There are a variety of theories about why we dream, such as to forget, to keep our brains working, or to rehearse and clean our synapses, but there is no singular reason
• REM (Rapid Eye Movement)


  Eyes move quickly during sleep
• NREM (Non-Rapid Eye Movement)


  Eyes are relatively stationary during sleep
• EEG (Electroencephalogram)


  Measures brain waves
• EOG (Electro-oculograph)


  Measures the potential of the muscles that contract and relax around the eyeballs
• Stages of sleep


  1. Awake (high frequency beta waves)

  2. Drowsy (alpha waves)

  3. Stage 1 (theta waves)

  4. Stage 2 (sleep spindles)

  5. Stages 3 and 4 (delta waves)

  6. REM (similar to awake stage)
• Sleep cycles through these stages in a cyclical manner, with about 4 cycles fitting into an 8-hour period
• REM periods increase in duration later in the night, just before waking up
• EEG is used to measure the brain wave activity and sleep cycles
• Demon and Kleitman's studies in 1955


  • Observed periods of REM during sleep
  • Found REM occurred in both normal and schizophrenic participants
  • Discovered REM appeared at regular intervals related to cyclic changes in sleep depth
• Some articles suggest babies don't dream until around age 2, as they don't have enough experience to construct reality in their brains
• However, we know babies experience REM sleep, so they may still dream in some capacity
• Babies do have REM sleep and display REM movements when they sleep
• Babies may be dreaming, but it is difficult to test what they are dreaming about
• Some people believe babies are having good dreams because they smile when they sleep
• Positive correlation


  When one variable increases, the other variable also increases, or when one variable decreases, the other variable also decreases
• Number of words in dream narratives was also used as a measure of dream duration
• Millionaires like Jeff Bezos and Oprah Winfrey sleep around 8 hours per night, while Tim Cook sleeps only 5-5.25 hours
• Sleep is important for health, but the exact reasons are not fully known
• Ideally, we should be getting about 7-8 hours of sleep per night
• Many successful people like Jeff Bezos, Oprah Winfrey, and Warren Buffett sleep around 8 hours per night
• Hippocampus


  During some sleep stages, it sends information to the cortex but not receiving any in return, allowing memories to be transferred for long-term storage
• Acetylcholine and noradrenaline


  The particular combination of these neurotransmitters during REM sleep may be the reason why we forget our dreams
• EOG measures eye movements, while EEG measures brain waves
• NREM sleep occurs in all stages of sleep except REM
• GABA and glycine neurotransmitters induce sleep paralysis, not REM sleep
• GABA and glycine are only released during REM sleep, not stages 3 and 4
• Sleep disorders can cause people to act out their dreams, leading to violent behavior while asleep
• The longest average sleeping time was 7 hours and 50 minutes
• WD experienced the most awakenings
• 152 dreams were recalled during REM sleep, compared to only 11 during NREM sleep
• WD was deceived, as he was told he would only be awakened during dreaming, but was actually awakened randomly during REM and NREM
• The 15-minute group was more accurate in estimating dream duration compared to the 5-minute group
• The correlations between REM duration and dream word count were all positive and significant
• Three of the dreams had vertical eye movements
• The positive/negative correlation only helps a little bit in determining if the correlations are significant
• The p-values are all less than 0.05, which is the standard rule of thumb for significance in the social sciences
• The authors noted there could be a lot of individual differences in recalling dreams
• Dream journal entries


  • Short, simple sentence
  • Essay (49 words)
• The dream with more words will correlate more strongly