Evaluation of Circadian Rhythms Flashcards
What does Siffre Show?
Siffre shows that circadian rhythms rely on EPs to run, but remain relatively constant in the absence of EZs.
What did Folkard say?
Circadian rhythms are resistant to being manipulated.
What did Morgan say?
Circadian rhythms are reliant on the SCN to function.
What did Hughes say?
Supports importance of light. Tested circadian hormones release in 4 participants stationed in Antarctica. In feb at the end of “summer” down there, cortisol levels were normal: highest as they worked and the lowest when they slept. Cortisol peaked at noon.
What did Hughes studies suggest?
Suggest not only the importance of light in keeping hormone rhythms stable, but also shows extremes of light can affect huge changes. (others didn’t find any changes).
what did Czeisler find?
Found that circadian rhythms vary from 13-65 hours.
What did Duffy find?
Found peak stages of each cycle vary - some people are ‘larks’ and some have ‘owls’. Therefore it is reductionist - assumes everyone will have the same biorhythms but evidence suggests otherwise.
Why could all this research with light be false?
They all utilized artificial light which has been proven by Czeisler to affect the sleep wake cycle.
