Discuss research in circadian rhythms. Refer to evidence in your answer (16 marks)

A ciradian rhythm is a cycle that revolves around a 24 hour clock, that keeps the body within a particular sleep-wake schedule. This rhythm is controlled biologically.

One piece of research into circadian rhythms is by Michael Siffre who had spent two months in the caves of the Southern Alps. Because of the conditions of the cave, he was deprived of light and sound and this procedure was used so that he could determine whether or not the circadian rhythm would maintain the same sleep schedule as before the study. The results of the study was that despite the fact that the cycle had stretched from 24 to 25 hours, his body maintained a good pattern of sleeping and waking, despite receiving no external cues from light.

Another piece of research into circadian rhythms is research done into people working night shifts. Research has shown that night shift workers will suffer from lapses in concentration at the early hours of the morning such as 6am, and this will result in more accidents and possibly detrimental mistakes. It was also found that night shift workers are three times more likely to suffer from heart disease as a result of the stress of constantly going against their natural sleep-wake cycle. A possible advantage of this research is that it has many economic impacts. For example, people are more aware of how night shift work can be detrimental to their health and so this is likely to result in less people working night shifts or more healthy schedules for workers being made to ensure that the risks that they face are minimised.

An evaluation of Michael Siffre’s study is that it shows that the body’s internal clock is set to 24-25 hours in the absence of external cues such as light, and does not tolerate any major alterations to the sleep-wake cycle.

However, research by Czeisler had found that dim artificial light was able to adjust the circadian rhythm between 22-28 hours. This means that the results of studies, such as Micahel Siffres, may lack in validity. Because it was found that artificial light can impact the sleep-wake cycle, this then has practical implications when it comes to products such as electronic devices like phones as it shows that these products should only be used at certain times of the day.

Another implication of research into circadian rhythms is that by understanding them and their impacts on health, it can help determine the best time to administer drug treatment. For example, the greatest risk of heart disease is in the morning, and so drugs (known as pharmacokinetics) can be taken at night, but will not be released into the bloodstream until morning, which is where it will be the most effective.