Infradian and ultradian rhythms

• What is the role of circadian rhythm in humans?

  It regulates the cycle of sleeping and waking.
• What does the term "circadian" mean?

  Circadian means around the day.
• What does "infradian" refer to in biological rhythms?

  Infradian refers to rhythms that occur less frequently than once a day.
• What does "ultradian" mean in the context of biological rhythms?

  Ultradian refers to rhythms that occur more than once every 24 hours.
• What is the menstrual cycle in humans?

  • A female cycle of fertility
  • Typically lasts 28 days
  • Includes a six-day period of fertility
  • Regulated by hormones estrogen and progesterone
• What is the duration range of the menstrual cycle?

  Between 24 to 35 days.
• What are endogenous pacemakers in the context of the menstrual cycle?

  They are internal body clocks that regulate biological processes.
• What biological changes occur during the menstrual cycle?

  Releasing the egg, thickening of the womb lining, and loosening of the womb lining during menstruation.
• What did McClintock's original research in 1971 find about menstrual cycles?

  Women living in the same dormitory synchronized their cycles by friendship groups.
• What did Russell's research in 1980 suggest about menstrual cycle synchronization?

  Synchronization could be due to women sharing pheromones.
• What did Stern's research in 1998 investigate regarding menstrual cycles?

  It investigated whether women could synchronize their cycles through pheromones.
• What is a criticism of the idea that pheromones synchronize menstrual cycles?

  Many studies have failed to replicate the findings of synchronization.
• What did Trevathan's research in 1993 find about cohabiting lesbian couples?

  They did not synchronize their menstrual cycles.
• What is a potential evolutionary advantage of synchronized menstrual cycles?

  It could prevent one male from dominating a group of females.
• What is a conflicting argument against the evolutionary advantage of synchronized cycles?

  Synchronization may be maladaptive as females compete for the best genes.
• What historical belief is associated with the menstrual cycle?

  It was thought to be controlled by the phases of the Moon.
• What did the study tracking 1.5 million women find about menstrual cycles and the Moon?

  There was no link between menstrual frequency and the Moon phases.
• What is the significance of the menstrual cycle in relation to chimpanzees?

  Chimpanzees have a 35-day cycle, but no correlation with menstrual synchronization was found.
• What are the strengths and weaknesses of the research on menstrual cycle synchronization?

  Strengths:

  • Some studies show synchronization among women.
  • Research on pheromones provides interesting insights.

  
  

  Weaknesses:

  • Many studies fail to replicate findings.
  • Variability in menstrual cycles can explain apparent synchronization.
• 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 material?

  The infradian rhythm
• What is the ultradian rhythm associated with?

  The stages of sleep
• What are the three types of rhythms mentioned in the study material?

  • Circadian rhythm (sleep/wake cycle)
  • Infradian rhythm (menstrual cycle)
  • Ultradian rhythm (stages of sleep)
• How frequently does the ultradian rhythm repeat?

  More frequently than every day
• What does the frequency of brainwaves refer to?

  The number of waves per second
• What does the amplitude of brainwaves refer to?

  The size of the wave
• 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 (non-REM)
  2. N2 (non-REM)
  3. N3 (non-REM)
  4. REM (rapid eye movement)
• What characterizes REM sleep?

  It is the stage in which you dream
• How long does one complete cycle of sleep take?

  Around 90 minutes
• How many cycles of sleep do humans usually have in one night?

  Between 4 and 5 full cycles
• What happens as you progress from N1 to N3 sleep?

  You move from light sleep to deeper sleep
• What is N1 sleep characterized by?

  A sensation of moving from awake to asleep
• What are hypnic jerks?

  Sudden movements that occur as you fall asleep
• What are hypnagogic hallucinations?

  Mild auditory or visual hallucinations during N1 sleep
• How can N2 sleep be identified on an EEG?

  By the presence of sleep spindles and K complexes
• What characterizes N3 sleep?

  It is known as slow-wave sleep