Bio Rhythms Infradian and Ultradian Rhythms Flashcards
example of Infradian Rhythm
menstrual cycle
menstrual cycle governed by
monthly changes in hormone levels
what does the cycle refer to
time between 1st day of womans period to the day before her next period
menstrual cycle governed by month changes in hormone levels regualte
ovulation
how many days does menstrual cycle last for
28days
what is range of menstrual cycle to last
24-35 days
during each M cycle what hormone rises
oestrogen
during each cycle rising lvls of oestrogen causes
ovulation
what type of system isnthe m cycle
endogenous system
evidence suggestgs men cycle may be influenced by
exogenous factors like cycles of other wmen
study by Stern and MClintock showed how
mens cycles may ych as a result of incluence of pheromeones
what happend in the stern and MClintock study
samples of pheromones gthered from 9 of women at diff stages of mens cycle via cotton pad placed in armpit
pads worn at least 9 hours to ensure phermones picked up
how were padws treated and to do what
with alcohol and frozen
to be rubbed on upper lip of other pt
On day one what ahppend to pads from start of menstrual cycle
applied to all 20 women
on day two what happned to what were all women given
pad from second day of cycle and so on
what were the result/ waht ddo Stern and McClintock find
68% of women xp changes to theri cycle
which brough them closer to cycle of odour donor
What is SAD
Deppressive disorder with a sasonal pattern onset
diagnosed as a mental disorder in DSM - 5
ass with other froms of depression wahta re the main symptoms of SAD
PERSISTEN LOW MOODS
ALONGSIDE GENERLA LACK OF ACTIVITY ADN INTEREST IN LIFE
SAD oftern reffered to as
winter blues
why si SAD referred to as winter blues
symptoms triggered durin winter months when # of daylight hours becomes shorter
what particlar type of infradian rhythm is SAD
Circannual rhythm
why is SAD a circannual rhythm
subject to a yearly cycle
why can SAD also be classified as a circ rhtym
xp of SAD may be due to disruption of sleep/wake cyle which can be attributed to prolonged perids of daily darkness during winter
what have psych hypothesised abut the hormone melatomnin
is implicated in the cause of SAD
Eplain how melatonin is implicated in the cause of SAD
During the night teh pineal gland secretes melatonin till dawn when tehre is an icnreae in light
during wintere lack of light in the morning means this secretion process continues for longer
this is thought to have a knock on effect on production of serotinin in the brain
serotonin is a chemical thats been lnked to
onset of depressive symptoms
ULTRADIAN RHYTHMS - what is one of the most intensivley researched ultradian rhythm
sleep cycle/ stages of sleep
ULTRADIAN RHYTHMS - how many distinct stages of sleep have pscyhoogists identified
5
ULTRADIAN RHYTHMS - these distinct stages of sleep last for around
90 minutes
ULTRADIAN RHYTHMS - each distinct satge of sleep cycle is characterised by
a differnt level of brainwave activity
ULTRADIAN RHYTHMS - how can rbainwave activity be monitores
using an EEG
ULTRADIAN RHYTHMS - outline hwat happens in stage 1 and 2
this is lgiht sleep - person may be easily woken
stage 1 - brain waves are high frequency and have short amplitude (alpha waves )
stage 2 - alpha waves continue but theres occasional random changes in pattern - called sleep spindles
ULTRADIAN RHYTHMS - explain stages 3 and 4
deep sleep or slow wave sleep (SWS)
Brain waves are delta waves - with lower frequency and higher amplitude
its difficult to wake someone at this point
ULTRADIAN RHYTHMS - what is stage 5 known as
REM sleep
ULTRADIAN RHYTHMS - explain stage 5
body is paralysed yet brain activity closely resembles that of the awake brain
during this time the brain prosuces theta waves and eyes occasionally move around so we get rapid eye movemetn (REM)
dreams are most often xp during REM sleep, but may alsso occur in deep sleep
eval
LIMITAITON of infradian rhythms - methodoligical limitations
a limititation of synchronisation studies is their x x
there are many x that ay effect changes to the x cycle including x , changes in x which can act asx x
which means that any x pattern of x is no more than would have been x to occur by x
this may explain why other x have x to x findings
this is limtiation as suggests menstrual synchrony x are x
a limititation of synchronisation studies is their metholodigcal shortcomings
there are many factors that ay effect changes to the menstrual cycle including stress , changes in diet which can act as confounding varibles
which means that any supposed pattern of synchrinisation is no more than would have been expected to occur by chance
this may explain why other studies have failed to relicate findings
this is limtiation as suggests menstrual synchrony studies are flawed
strenght - infradian rhythms - evolutinoary basis
strenght of menstrual synchrony research is it may be explained by x x
x of the menstrual cycle of the kinf observed int eh x and x study is thought by some to have x x
for our x ancestors it may have been x for women to x together and become x at the same tie
in a x group this would allow babies who have x theor x during or x x to have access to x x therfore x their chances of x
this is suggest synchronisation is an x strategy
strenght of menstrual synchrony research is it may be explained by natural selection
synchronisation of the menstrual cycle of the kinf observed int eh stern and mcclintock study is thought by some to have evlutionary value
for our sidtant ancestors it may have been advantageoues for women to menstruate together and become pregnant at the same tie
in a social group this would allow babies who have lost theor mother during or after childbirth to have access to breast milk therfore improving their chances of survial
this is suggest synchronisation is an adative strategy
- research support role of melatonin in SAD
Finally, evidence supports the role of X in SAD. Terman (1988) found that the rate of XXX is more common in X countries where the X nights are X.
For example, X found that SAD affects roughly X% of people living in New X (a X part of the US) and only X% of residents in X Florida. These results suggest that SAD is in part affected by X (exogenous zeitgeber) that results in increased levels of X.
Finally, evidence supports the role of melatonin in SAD. Terman (1988) found that the rate of SAD is more common in Northern countries where the winter nights are longer. For example, Terman found that SAD affects roughly 10% of people living in New Hampshire (a northern part of the US) and only 2% of residents in southern Florida. These results suggest that SAD is in part affected by light (exogenous zeitgeber) that results in increased levels of melatonin.
STRENGTH RESEARCH INTO ULTRADIAN RHYTHMS
its x our understanding of x related changes in x
x scientists have observed that SWS x with x
x hormone is mostly produced during SWS therefore this is x in x people
according to xx et al the resulting sleep x may explain various x in x age such as x x
in order to incrase SWS x and x may be used
this suggests x of ultradian rhythms has x value
its improved our understanding of age related changes in sleep
sleeep scientists have observed that SWS reduces with age
growth hormone is mostly produced during SWS therefore this is reduced in older people
according to van cauter et al the resulting sleep deficit may explain various issues in old age such as reduced alertness
in order to incrase SWS relaxation and medicatino may be used
this suggests knowledg of ultradian rhythms has practical value
limtation RESEARCH INTO INFRADIAN RHYTHMS - individual differnces
a limtiatino of ultradian rhythm research is there is a significant x between people
x et al found large x beteen participants in terms of the x of each sleep cycle ptclry x&x
x et al suggests these differnces are likely ot be x x
this makes it x to describe x sleep in any x way
a limtiatino of ultradian rhythm research is there is a significant variations between people
tuckee et al found large differnces beteen participants in terms of the duration of each sleep cycle ptclry 3&4
tucker et al suggests these differnces are likely ot be biologically determined
this makes it difficult to describe normal sleep in any meaningful way
evaluation extra sleep lab
benefit of conducting studies of sleep in a lab is control of x variables
this means the researche can x temporary variables such as x or x tjat amy affect x
this increases the x validity of the experient whihc increases x of x
however lab studies involve being x to x machinery leading pt to sleep in a way that doesnt represent x sleep patterns so these studies have low x x and x validity
benefit of conducting studies of sleep in a lab is control of extraneous variables
this means the researche can exclude temporary variables such as noise or temperature tjat amy affect sleep
this increases the internal validity of the experient whihc increases genuinity of findings
however lab studies involve being atatched to compicated machinery leading pt to sleep in a way that doesnt represnt ordinary sleep patterns so these studies have mundane realisma nd external validity
