E.Z's and E.P's evaluation

Question 1

One strength of the role of E.P’s is that there is research support from Ralphs study on mutant hamsters

Answer 1

Support for the E.P of the SCN on the sleep-wake cycle as the normal hamsters have adopted the sleep-wake cycle of the mutant hamsters SCN.

The strength of this animal study is that manipulation of the SCN was conducted under CONTROLLED CONDITIONS and so this means that there are LESS confounding vairables as it has been controlled so it has HIGH i.v.

HOWEVER, there are issues in generalising these findings due to animal EXTRAP. WE cant take findings of animals roles of the SCN and generalise them back to humans as we can;t be SURE that the effect on animals and humans SCN are the same.

Question 2

One issue is that it may be TOO Reductionist to suggest that the SCN is the ONLY e.p responsible for regulating the sleep-wake cycle

Answer 2

Research demonstrated that there are many peripheral oscillators found in many othehr organs of the body including the adrenal gland, oesophagus etc that not only function in combination with the SCN bu have the ability to work independently.

This therefore suggests that we need to take a more INTERACTIONIST approach looking at the important interaction between the effect of MANY ep’s on the sleep-wake cycle not just the effect of the ep SCN.

Question 3

Further, Campbell and Murphys research demonstrated that light does not need to enter the eyes and stimulated the SCN in order to have an effect on the sleep wake cycle.

Answer 3

But other psychologists suggested that the participants my have had some limited exposure to their eyes which would become a CONFOUNDING variable, lowering the IV of the study on light detected by skin receptors when there’s a chance that the EZ of light has still been exposed to the eyes and so effected the results.

They only ISOLATED light in this experiment, did not control influence of other e.z’s such as time meals were taken and so this could have an EFFECT on the sleepwake cycle, but this study is LIMITED and only tells us about the effect of the EZ of LIGHT on the sleep-wake cycle.

Question 4

weakness is that E.Z’s role may be overstated as there’s evidence that although external enviornmnetla cues may vary, some individuals pacemakers are set to WITHSTAND their influence.

Answer 4

MILES casestudy, blind from birth, circadian rhythm of 24,9 hours and his sleep cycle could NOT be adjusted regardless of changes to SOCIAL CUES. Required MEDICATION to allow him to sleep and wake at the appropriate times.

SHOWS that E,z’s may not ALWAYS be able to entrain our sleep-wake cycle, but psychologist would argue that this study is an example of an EXCEPTIONAL circumstance and that for most people there is an interaction between our ep’s and e.z’s that sets our circadian rhythm.

ALSO idiographic.

Question 5

endogenous pacemakers are biologically reductionist

Answer 5

recuces complex issue of sleepwake cycle and reduces it down to just bio factors like SCN and pineal gland which is an issue as other external factors may be inluencing like EZ’s

Question 6

exogenous zeitgebers are an example of environmental reductionism

Answer 6

take the complex issue of sleep wake cycle and reduce it down to just the simple cause of environment such as light or social cues which is an issue as they may miss other important factors influencing sleep wake cycle such as biological ones like our ep’z.