ultradian & infradian rhythms L10

• What are infradian rhythms?

  Cycles with a duration longer than 24 hours
• What is an example of an infradian rhythm?

  The menstrual cycle
• How long can the menstrual cycle vary?

  Between 25 and 36 days
• What is the average duration of the menstrual cycle?

  28 days
• What regulates the menstrual cycle?

  Hormones
• What did Tucker et al. (2007) assess in their study?

  Sleep duration, time to fall asleep, and the amount of time in each sleep stage
• What were the findings regarding individual differences in sleep patterns?

  There were large, consistent individual differences
• What are ultradian rhythms?

  Cycles lasting less than 24 hours
• How long do ultradian rhythms typically last?

  90-100 minutes
• What is the characteristic pattern of brainwaves during deep sleep?

  Brainwaves slow down

  
• What happens to heart rate during deep sleep?

  Heart rate decreases
• What is the relationship between elite performers and the 90-minute practice rhythm?

  Elite performers generally practice for no more than 90 minutes at a time
• What did Ericsson et al. (2006) find about elite violinists?

  They found that elite violinists have a characteristic practice rhythm
• What is the Basic Rest Activity Cycle (BRAC)?

  A 90-minute rhythm that continues throughout the day
• How do menstrual cycles synchronize among women living together?

  They tend to synchronize when they do not take oral contraceptives
• Who conducted a study on synchronized menstrual cycles?

  Russell et al. (1980)
• What are the key characteristics of infradian rhythms?

  • Last longer than 24 hours
  • Example: menstrual cycle
  • Regulated by hormones
  • Individual differences in sleep patterns
• What are the key characteristics of ultradian rhythms?

  • Last less than 24 hours
  • Cycle duration: 90-100 minutes
  • Includes stages of sleep (e.g., REM)
  • Characteristic EEG patterns
• What are the implications of the BRAC for performance?

  • 90-minute cycles of alertness and fatigue
  • Optimal practice duration for elite performers
  • Synchronization of activity with natural rhythms
• Infradian Rhythms


  Infradian rhythms refer to physiological processes that have a cycle longer than 24 hours.
• Circadian Rhythms


  Circadian rhythms are biological processes that follow a 24-hour daily cycle, influenced by light-dark cycles and internal clocks.
• Example of Infradian Rhythm


  Menstrual cycle
• Difference between Infradian and Circadian


  Infradian rhythms are longer than 24 hours, while circadian rhythms are 24 hours. Infradian rhythms are influenced by hormones, while circadian rhythms are influenced by light-dark cycles.