ultradian rhythm

• What can be observed by an electroencephalogram while you sleep?

  Distinctive brainwave patterns
• How often do brainwave patterns repeat during sleep?

  Every 90 minutes
• What is the 24-hour circadian rhythm known as?

  The sleep/wake cycle
• What is the menstrual cycle referred to in the study?

  The infradian rhythm
• What is the ultradian rhythm related to?

  The stages of sleep
• What are the three types of rhythms discussed?

  • Circadian rhythm
  • Infradian rhythm
  • Ultradian rhythm
• How does the frequency of ultradian rhythms compare to circadian rhythms?

  Ultradian rhythms are more frequent than daily
• What are the five main distinctive brainwave patterns?

  Delta, theta, alpha, beta, gamma
• What happens to brainwave patterns as sleep becomes deeper?

  Slower patterns like theta and delta dominate
• What are the four distinct stages of sleep?

  1. N1 (light sleep)
  2. N2 (moderate sleep)
  3. N3 (deep sleep)
  4. REM (rapid eye movement sleep)
• What characterizes N1 sleep?

  Easy to wake, hypnic jerks occur
• What waves are present in N1 sleep on an EEG?

  Theta waves
• What happens during N2 sleep?

  Heart rate and body temperature fall
• What identifies N2 sleep on an EEG?

  Sleep spindles and K complexes
• What is N3 sleep also known as?

  Slow wave sleep
• What waves are present in N3 sleep on an EEG?

  Delta waves
• What characterizes REM sleep?

  Active brain state similar to wakefulness
• What is another name for REM sleep?

  Paradoxical sleep
• What happens to the proportion of REM sleep in each cycle?

  It increases compared to NREM sleep
• How many full sleep cycles do humans usually have in a night?

  4 to 5 cycles
• What did Kleitman’s studies in 1957 demonstrate?

  Regular sleep cycles using EEG recordings
• What did Shapiro's research in 1981 find about sleep?

  Intense physical activity leads to longer sleep
• What is the debated function of REM sleep?

  Memory consolidation
• What did Hyder's research in 1970 suggest about REM sleep?

  It is for brain recovery
• What percentage of sleep do babies spend in REM?

  About 80%
• How does understanding sleep stages benefit individuals?

  Helps track and improve sleep quality
• What was combined in 2007 regarding sleep stages?

  The old stages 3 and 4 were combined
• What did Caesar's research in 1980 find about REM sleep?

  It coincides with the lowest body temperature
• What is nocturnal penile tumescence (NPT)?

  Erection during sleep in men
• How often does NPT occur during the night?

  About five times a night
• What is the suggested purpose of NPT?

  To provide oxygenated blood to the penis
• What are the implications of understanding sleep cycles?

  • Improved sleep tracking
  • Enhanced sleep quality
  • Healthier and more productive population