| What is endogenous menstrual cycle? | Occurs around every 28 days, endogenous control by the hormones oestrogen and progesterone |
| What is menstrual cycle exogenous? | Stern and McClintock found that the menstraul cycle is entrained through exposeure to odour dononr's pheromones |
| What is SAD? | Depression associated with seasonal changes, usually the onset of winter and decreased darkness |
| What are the stages of sleep? | Span 9- minutes, stage 1 - 5 REM. Brain activity changes |
| What is ultradian rhythm? | Frequency of more than one cyclle in 24 hours, such as the stages of sleep |
| What is a infradian rhythm? | Frequnecy of less then on cycle in 24 hours, such as menstruation cycle and SAD |
| How is the menstrual cycle a endogenous system? | Rising level sof oestrogen cuases the ovary to realse an egg. The progesterone helps the womb lining to thicken, readyingthe womb for pregnancy, if this doesn't happen, the egg is absorbed and the womb lining comes away |
| What did Stern and McClintok find ? | Studied 29 women with irregular periods.
Pheromeones were taken from some at different stages of their cycle with cotton pads under their arms. Cleaned with alcohol and later rubber on the upper lips of other ppts
68% of the women experinced changed in their cycle to come closer to the 'odour donor' |
| A strength of infradian rhythm? | -Menstrual cycle shows its a evolutionary bias
-Distant ancestros may have been advantagoues for females to menstruate together and become preganant at the same time
-In a social group, this would allow for babies who had lost thier mothers to have access to breast milk, improving their chances of survival
-Suggests that synchronisation is an adaptive strategy |
| A weaknes sof infradian rhythm? | -Methology used in synchronisation studies
-Supposed parttern may have occured by chance, this may be why other stuides, such as Trevathan et al, have not be able to replicate the original findings by Stern and McClintock.
-There are many factors that may change a woman's menstrual cycle and act as confounding variables (stress, changes in diet)
-Suggests that menstrual synchrony studies are flawed |
| What is the overview of stage 1 and 2 sleep cycle? | Light sleep where are person can be easily woken |
| What is stage 1? | Brain waves are high frequency and have a short amplitude. Alpha waves |
| What is stage 2? | Alpha waves continue but there are occasional random changes in pattern called sleep spindles |
| What is stage 3 and 4 of sleep cycle? | Deep sleep or slow wave sleep (SWS)
Brain waves are delta waves with lower frequency and higher amplitude. Difficult to wake someone up at this point |
| What is stage 5 of sleep cycle? | REM sleep, the brain is paralysed yet brain activity resembles that of the awak brain
Brain produces theta waves and eyes move, rapid eye movement
Dreams are experiences in REM but also in deep sleep |
| A strength of ultradian rhythm? | -Understanding age related changes in sleep
-Van Cauter at al suggests that reduced sleep may explain impairments in old age. SWS sleep can be improved used relaxation and medications
-SWS reduces with age. Growth hormone in produced during SWS so this becomes deficient with other older people
-Suggest that knowlege of ultradian rhythms has practical value |
| A weakness of ultradian rhythm? | -Individual differences in sleep stage
-Tucker et al found large differences between ppts in duration of stage 3 and 4
-Suggests that these differences are biologically determined
-Makes it difficult to describe 'normal sleep' in any meaningful way. |
