Function of Exogenous Zeitgeber's and Endogenous Pacemakers
We have an internal body clock the lasts the duration of a day (24 hours), which is therefore able to control the circadian rhythm. As the biological body clock is controlled inside it is known as endogenous, these are called endogenous pacemakers. So how do these work on their own to affect the sleep-wake cycle and why do we need external factors to also help control our circadian rhythms?
There have been many studies into endogenous pacemakers to see if our sleep-wake cycle (circadian rhythms) will still last 24hours without any exogenous zeitgebers(external factors) influencing this internal body clock.
Folkard study
In order to study internal pacemakers you need to take away all possible external factors. Folkard achieved this by doing a study where 6 students spent a month isolated from these external cues. He recorded data and findings from the children by monitoring temperature, activity level and mood every 2 hours. With the absence of external factors, biological findings proved the existence of internal body clocks which control sleep/waking temperature etc. This study was carried out well. Folkard chose a good length of time so the students could adjust and the conditions were as realistic as possible as the students were given tasks that they’d normally do e.g. playing bagpipes, the closest you could get to a field study without external factors. Therefore results found are quite reliable but although Folkard found evidence of endogenous pace makers, results may be hard to generalise because the sample size was fairly small and all of similar age and you have to be careful of confounding variables affecting results as the students knew each other and could be synchronised with each other to when they should eat together as a group and sleep.
Siffre cave study.
Similarly another study also took place with a participant isolated from external factors to prove the existence of endogenous pacemakers without interference of the outside world. Siffre
There have been many studies into endogenous pacemakers to see if our sleep-wake cycle (circadian rhythms) will still last 24hours without any exogenous zeitgebers(external factors) influencing this internal body clock.
Folkard study
In order to study internal pacemakers you need to take away all possible external factors. Folkard achieved this by doing a study where 6 students spent a month isolated from these external cues. He recorded data and findings from the children by monitoring temperature, activity level and mood every 2 hours. With the absence of external factors, biological findings proved the existence of internal body clocks which control sleep/waking temperature etc. This study was carried out well. Folkard chose a good length of time so the students could adjust and the conditions were as realistic as possible as the students were given tasks that they’d normally do e.g. playing bagpipes, the closest you could get to a field study without external factors. Therefore results found are quite reliable but although Folkard found evidence of endogenous pace makers, results may be hard to generalise because the sample size was fairly small and all of similar age and you have to be careful of confounding variables affecting results as the students knew each other and could be synchronised with each other to when they should eat together as a group and sleep.
Siffre cave study.
Similarly another study also took place with a participant isolated from external factors to prove the existence of endogenous pacemakers without interference of the outside world. Siffre