circadian rhythm Flashcards
what are some examples of social cues?
•temperature
•sounds
-birdsong
-people talking/ in your house
-cars/ binmen
-alarms
what are the two exogenous zeitgebers?
social cues and sunlight
who conducted the cave study?
Siffre
what was the aim of Siffre’s cave study?
to study the effect of removing exogenous zeitgebers on biological rhythms (endogenous pacemakers)
what was the procedure of Siffre’s cave study?
he spent months underground in a cave, deprived of exposure to natural light and sound, but with access to adequate food and drink
what were the findings of Siffre’s studies?
•his circadian rhythm ‘lengthened’ to 25.5 hours and became ‘free- running’
•Siffre repeated this study in 1972, this time he spent 7 months in a cave in texas, and made the same findings
other research displaying innate circadian rhythms
participants staying in a blacked out WW2 bunker all (but one) displayed circadian rhythms between 24 and 25 hours
what do research findings suggest about circadian rhythms?
that the ‘natural’ sleep/ wake cycle might be slightly longer than 24 hours but is entrained by exogenous zeitgebers associated with our 24 hour day
evaluation points:
+ real world application, shift work
+ medical treatment
- case studies and small samples
+german bunker study
+shifting the school day
strength: real world application- shift workers
•it provides an understanding of what happens if our sleep is disrupted
•research shows that shift workers may experience a period of reduced concentration at around 6am which could cause more accidents to happen
•shift workers are three times more likely to develop heart disease than people who work more typical work patterns
•this shows that research into the sleep/ wake cycle may have real-world economic implications in terms of how best to manage worker productivity
counterpoint of the shift work evaluation point
•studies investigating the effects of shift work tend to use correlational methods
•this means it’s difficult to establish whether the desynchronisation of the sleep/ wake cycle is actually a cause of negative effects
•eg high divorce rates in shift workers may be due to the lack of sleep as well as things like missing out on important family events
strength: medical treatment
•understanding has been used to improve medical treatments
•more research has been done into how medical treatments can be administered in a way that corresponds to a persons biological rhythms
•eg aspirin is more effective if taken last thing at night for treating heart attacks
•this shows that circadian rhythm research can help increase the effectiveness of drug treatments
limitation: the use of case studies and small samples
•they may not be representative
•lacks generalisability
strength: german bunker study
•a group of uni students lived in a bomb shelter for a month and found results similar to siffe’s study
•many days lengthened to 25 hours
•this suggests that our sleep/ wake cycle may be slightly longer than 24 hours but that it is entrained by exogenous zeitgebers
•shows the existence of individual differences in the sleep/ wake cycle
strength: shifting the school day
•researchers suggested that the school day starts a couple of hours later to fit in with the typical teenage sleep/ wake pattern
•research shows that academic and behavioural performance is often better if lessons start later in the day
•shows the effects of research on real life contexts
