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Discuss psychological research into body rhythms

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Discuss psychological research into body rhythms Body rhythms are periodically repeated patterns which occur within the body and are governed by internal factors known as endogenous pacemakers, such as hormones and external factors known as exogenous 'zeitgebers' (time-givers), such as light and dark. The three main classifications of body rhythms are: Circadian is a twenty-four hour cycle, for example sleep and wakefulness, Ultradian is less than the twenty-four hour cycle, for example sleep stages and Infradian which is longer than the twenty-four hour cycle, for example the menstrual cycle. Over the years there have been numerous experiments to establish the causes of body rhythms and the effects of altering them. One theory which inspired such research was based on the suprachiasmatic nuclei (SCN), which are the neurons situated in the hypothalamus. The SCN, in conjunction with the pineal gland, were predicted to be factors determining the regulation of the circadian rhythm. ...read more.


The 'sample' also had low validity because it was self-selecting, did not have any variables, was based on only one individual and was not repeated to substantiate the conclusions. Demand characteristics could also be argued, as Siffre had predetermined expectations of what would happen to his behavioural patterns. Another argument could be that the experiment was carried out on humans only and therefore would the same results occur in other animals. This was resolved by undertaking a similar experiment on rats in which the SCN was removed from the rat altogether. The findings illustrated that the rats circadian rhythm disappeared altogether, adding weight to Siffre's theory. Similarly, Geetha (1989) participated in an experiment referred to as 'My Life in a Bunker'. Geetha lived in a timeless environment (facility) for thirty-five days with artificial lighting, no zeitgebers and no contact with the outside world other than written notes and with recording apparatus to monitor her behavioural patterns and physiological functions. ...read more.


However, her second stay was cut short due to mitigating circumstances and it could be argued that there were demand characteristics, as she knew what to expect from her previous experience. Research has proven repeatedly that our bodily rhythms are reliant on both endogenous and exogenous factors, ruling out the reductionist theory that there is only one cause accountable for maintaining our bio-rhythms. Evidence shows that if we relied on our endogenous pacemaker alone we would have a naturally longer internal clock and we would not be able to reset or adjust the internal clock to coincide with daylight hours, different time zones, shift work and all individuals would sleep for the same amount of time. On the other hand if we relied solely on exogenous zeitgebers we would still face difficulties as individuals lead different lives for a variety of reasons such as work schedules, social lives, health issues and age. Due to the complex nature of the human body our internal clocks can be adjusted using zeitgebers, which is ultimately essential to assist us with our modern way of life. ...read more.

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