Infradian and ultradian-EVAL

Question 1

infradian STRENGTH:
menstrual cycle research can be explained through natural selection

Answer 1

E.g. synchornisation of the menstrual cycle as shown in mcclintock study is thought to have EVOLUTIONARY value. may have ADVANTAGES for our ancestors to menstruate toegether and become pregnant at the same time.

This would enable our mothers to look after babies if the babies OWN mum couldn’t. e.g. illness or death which would enhance babies survival.

Therefore, suggesting that this synch of the infradian menstrual cycle is an adaptive strategy with an evolutionary advantage.

Question 1

infradian WEAKNESS: menstrual cycle study has POOR control

Answer 1

Other variables like EXERCISE or STRESS may be altering our menstrual cycles. This is an issue because it LOWERS our IV of the study making us UNSURE whether we’re measuring what was intended.

Therefore the synch of the infradian rhythm of the menstrual cycle may NOT be measured accurately in this study, questioning the conclusion that cycles CAN be synchronised.

Question 2

infradian STRENGTH: research into the infradian rhythm of SAD (seasonal depression) has practical applications.

Answer 2

Led to the development of light therapy, whereby a box giving out very strong light is used to reset the bodys internal clock and REDUCES the effects of SAD in about 80% of people.

This is a STRENGTH of research into the infradian cycle of SAD as it has lead to the REAL LIFE application of light therapy, which has less side effects than traditional therapies such as anti-depressants.

Question 3

ultradian STRENGTH: improved understanding of age related changes in sleep

Answer 3

e.g. sleep scientists observed that SWS increases with age. Growth hormone mostly produced during SWS, which is reduced in oler people. Age related sleep deficit can explain various issues in old age such as reduced alertness, meds can be used to increase SWS if needed.

THEREFORE, this shows that the research into ultradian rhythms has PRACTICAL value as it has INCREASED our understanding of age-related issues and also lead to medication being developed to increase SWS

Question 4

ultradian: WEAKNESS

significant indiviudal differences

Answer 4

Tucker found large differences between ppts in terms of duration of each stage of sleep, particulary 3 and 4. Suggest these differences to be BIOLOGICALLY determined.

This is a PROBLEM as it becomes increasingly DIFFICULT to be able to make only MEANINGFUL conclusions about what makes ‘normal’ sleep cycles in the ‘normal’ ultradian rhythms.

Question 5

ultradian:STRENGTH

research is conducted in sleep labs

Answer 5

Strength as we are able to MANIPULATE the variables and CONTROL extran variables stopping them from becoming confounding and affecting the INTERNAL validity of the study meaning that cause and effect CAN be established. Increasing SCIENTIFIC validity of the study.

Therefore the ultradian rhythms research has scientific cred, showing that we ARE measuring ultradian rhythms as intended.

BUT a problem with sleep labs is that they may NOT represent ORDINARY sleep as the ppts are attached to MACHINERY which is likely to AFFECT the quality of the sleep. This is a CONFOUNDING variable ib the study, lowering the IV questionig if we are measuring the ultradian rhythms as intended.