eval

• siffre - supports

  • absence of external cues altered his circadian rhythm
  • when he returned back to normal ground he thought it was a moth earlier than it was
  • suggests his sleep wake cycle was altered by a lack of EZ
• aschoff and weber


  • link to siffre study - in a similar environment but in a bunker
  • sleep wake cycle increased to 27 hours
  • suggests humans need real light for to regulate their circadian rhythms
• siffre - eval


  • problems with it being a case study - reductionist
• morgan - hamsters


  • bred hamsters so that their sleep wake cycle was 20 hours
  • SCN neurons from these hamsters were put in the normal hamsters which led them to have the same sleep wake cycle
  • suggests the SCN is important and so are EP for regulating circadian rhythms
• morgan - eval


  • unethical - animal studies
  • animals arent fully related to humans - humans more complicated