exogenous Zeitgebers

• exogenous Zeitgebers - any external factor from the environment that influences biological rhythms such as the sleep/wake cycle

  main exogenous Zeitgeber = light

  differences in light intensity can instruct scn to inform pineal gland whether to release melatonin or not

  if natural light isn't present, then social cues such as meal times or bed times can affect sleep/wake cycle
• CAMPBELL AND MURPHY

  created deviations in participants sleep/wake cycle by 3 hours through shining light onto pads on the back of the knees

  this shows the importance of light in these biological rhythms and how light doesn't just need to be detected by eyes to disrupt regular sleep/wake patterns
• A03

  + research into disruption of circadian rhythms has been beneficial as it has allowed methods to be developed to reduce the mistakes made by workers with decreased alertness. for example, Boivin exposed participants to different intensities of artificial light, acting as an exogenous zeitgeber and found that their wakefulness increased which improved their alertness. thus; has practical application as it can help increase peoples well being and health which increased QOL and also has good economic implications reducing costs made from mistakes