infradion rhythms Flashcards
infradian rhythms
biological rhythm where there is less than 1 cycle in a 24 hour period
what is a type of infrdian rhythm
menstrual cycle
what is the menstrual cycle
monlthy changes in hormone levels - ovulation
how long is the menstrual cycle and what causes explain
28 day cycle
oestrogen causes relapse of an egg, progesterone grows lining ready for pregnancy
if not egg absurd lining shed
synchronising the menstrual cycle who study it
stern and McClintock 1990 believed periods could be affected by exogenous factors
studied influence of pheromones
what was the stern McClintock stuff
29 women who had irregular period history
pheromone samples collected from 9 women at different period stages
pacts rubbed on upper lib of 20 women on day 1 then day 2 etc
what were the findings of stern and McClintock
found 68% of women experienced changes to their cycle alining it with their odour donor
what is seasonal affective disorder
SAD is a depressive disorder that occurs during winter months when daylight hours shortens
what are the symptoms of seasonal affective disorder
regular depression symptoms
lack of energy
lack of motivation to carry out day to day actives
change in appetite for better or loss worse
what is SAD classed as and why
infradian circannual rhythms but also classed as circadian as symptoms could be due to disruption to sleep/wake cycle
what did SAD attribute to
also attributed to pineal gland secreting melatonin for longer as dark hours are extended
knock off effect on serotonin secretion
evaluation evolutionary basis
strength of menstrual synchronisation
ancestors found it advantageous to menstruate and pregnant together
allowed babies who lost mothers to be fed and service
suggests synchronisation was an adaptive strategy
evaluation methodological issues
many factors affect menstruation stress Diest exercise etc
all confounding variables that mean any patterns of synchronisation can be due to chance
explains why other studies failed to replicate findings
evaluation real world application
light therapy as a treatment for SAD
uses light to reset body clock
helped reduce symptoms of SAD by 20%
