Circadian Rhythms Flashcards
define circadian rhythms
about a day, 24 hour cycle such as the s/w cycle and changes in core body tempature
which french caver spent long periods in dark caves to examine the effects of free running biological rhythms?
Siffre
what did Siffre find?
that his free-runnning circadian rhythm settled down to just above the uusual 24 hours (25hours)
how did Aschoff and Weaver (1976) also examine the effect of a free running circadian rhythm?
participants spent 4 weeks in a WW2 bunker deprived of natural light
what did A&W(1976) find?
all but one (cr extended to 29 hours) displayed a circadian rhythm between 24 hours and 25 hours.
what do these studies into a free-running circadian rhythm suggest?
- the ‘natural’ s/w cycle may be slightly longer than 24 hours
- but is entrianed by exogenous zeitgebers associated with our 24-hour day (number daylight hours, typical mealtimes)
what did Frokard’s study (1985) suggest
endogenous pacemakers may have a greater influence than exogenous zeitgebers
A03) what are 2 strengths of circaidan rhythms?
- practical application to shift work
- practical application to drug treatments
A03) what did Bovin (1966) find about shift work?
- found shift workers experience a lapse in concentration around 6 am (circadian trough)
- so mistkaes and accidents are more likely
what is the practical application of Boivin’s (1966) research?
may have economic implications - how to best manage worker prodcutivity
A03) what is the practical application to drug treatments?
- implications for pharmacokinetics - research into times of day where drugs are most effective
- guidelines have been developed for the timing of dosing
A03) what is one limitation of circadian rhythm research?
used of case studies and small sample sizes
A03) why is this a limitation?
participants may not be representative of the wider population - this limits making meanaingful generalisations
