Circadian rhythm-EVAL Flashcards
STRENGTH: research supporting it’s existence (Siffre’s studies)
Siffre spent several periods underground to study his own bio rhythms and found that his ‘Free-running’ bio rhythm settled down to 25 hours and he continued to sleep-wake on a regular schedule.
This supports the ROLE of our ep’s in the circadian sleep/wake cycle as the cycle still settled down to a rhythm DESPITE the ABSENCE of the EZ of LIGHT.
However, it also shows the IMPORTANCE of the ez of light in the sleep-wake cycles the absence meant that it wasn’t TRULY circadian as it wasn’t 24 hours.
So there’s an Important INTERACTION between the eps and ezs as the Ez may ENTRAIN the circ sleep-wake cycle
WEAKNESS: research into circ rhythms has POOR control. Cave studies, exposure to ARTIFICIAL lights such as torches and phones were NOT controlled. Was assumed only NATURAL light has an influence on our bio rhythms, but research found that dim artificial light could ADJUST the rhythm from 22-28 hours.
Therefore, these studies may LACK I.V as the artificial light becomes a CONFOUNDING variable in the studies as it was NOT controlled.
Means research into circ rhythms of sleep-wake cycle is NOT measuring what it’s SUPPOSED to be measuring I.E absence of light and so we can’t be sure to the conclusion made with regards to the Eps and Ez’s in the circadian sleepwake cycle.
STRENGTH: Practical application.
SHIFT WORK: found to lead to desynchronisation of circ rhythms can lead to cog and physiological affects. Night shift workers suffer a concentration LAPSE at 6am, INCREASING likelihood of accidents, 3 times more likely to suffer from heart disease as a result of stress of adjusting sleep-wake cycles.
This may have implications for the ECONOMY as the de-synchronisation of the circ rhythms may lead to ACCIDENTS impacting on costs for the companies in terms of COMPENSATION, damage that may be caused and loss of production.
Therefore this research into the impact of shift work on our circ rhythms and accidents could be positive as it could help us to PREVENT accidents happening as a result of this de-synchronisation E.g. if research suggests concentration lapses at 6am then we could ADVISE companies to give workers a BREAK at that time, helping to REDUCE accidents and economic implications.
HOWEVER, an issue is that we shouldn’t INFER causation from a correlation and so we cannot ASSUME that the desync of circ rhythms has caused the neg. effects. E.g. Solomon says high divorce rates in shift workers may be due to the strain of deprived sleep and other influences e.g. missing out on important family events and so it may NOT be biological factors that create consequences associated with shift work.
WEAKNESS: individual differences, cycles can vary from 13-65 hours, some people have a natural preference for going to bed early and rising early whilst others prefer sleeping late and waking late. Also differences such as age, teens cycles start later than adults.
Therefore this is an issue as it means we CANNOT necessarily GENERALISE from these studies as peoples circadian rhythms may vary. Therefore, IDIOGRAPHIC case studies e.g. Siffre may represent THEIR circ rhythms in detail, but the circ rhythms would NOT necessarily be the same for everyone, lowering the POP. val of the studies.
