Biological Rhythms

• Circadian rhythm

  Regulates bodily functions such as sleep-wake cycle and temperature
• Circadian rhythms affected by:

  • Light
  • Social cues
• Infradian rhythm

  Less frequent than 24 hours. Includes the menstrual cycle and pregnancy
• Infradian rhythms affected by:

  • Pheromones
  • Light
• Ultradian rhythm

  More frequent than 24 hours. Includes blood circulation and blinking
• Evaluation of circadian rhythms

  • Practical application
  • Case studies
  • Biological determination
• Evaluation of infradian rhythms

  • Evidence
  • Extraneous variables
• Evaluation of ultradian rhythms

  • Methodological issues
  • Ecological validity