biological rythms Flashcards
biological rhythm
repeated patterns of changes in the body that are regulated by an internal clock
circadian ryhthm
24 hour often known as body clock
reset by levels of light
sleep wake
endogenous pacemakers
internal timing devices that regulate biological rhythms
rhythms from internal bodily systems can be affected by the environment
still function without cues from the environment
sleep wake
exogenous zeitgebers
external curs important in controlling the accuracy of biological rhythms
cues from the environment that regulate time
enable individuals to be synchronised with environment
suprachiasmatic nucleas
lies in hypothalamus
send signals to pineal gland
contains receptors that are sensitive to light and this external cue is used to synchronise bodys internal organs and glands
siffre
he was the participant
spent 6 months in cave with no natural light
lost track of days, believing he wad in the cave for 5 months
allowed his body clock to free run and settled into a 25-30 hour cycle
shows natural light is important
critisms of the siffre
cant generlise- indvidual differences
idiographic data
evaluation
only looking at the role of nature is reductionist other need to be taken into account
practical applications- curtains, alarm clocks
determinism vs free will
infradian ryhtms
longer than 24 hours could be weekly, annually, monthly
menstral cycle
sad
menstrual cycle
roughly 28 days
pms
crime goes up 63-84% of female crime on pms
McClintock and Stern
suggested phermones causes the womens cycles to synchronise
longitudinal
collected odourless compounds of swear from a donors underarms at different stages of the cycle snd wiped this above the upper lip of women
pheromones from women in the early phases of their cycle= lengthened
pheromones from women in later in the cycle (during ovulation)= shortened
evaluation of McClintock and Stern
+ women who worked with men have shorter cycle. Suggests male pheromones reset a women’s biological clock
-biological ryhtms are beyond out control. Dalton suggestd PMS is associated with an increase in accidents lower academic performance, sucide and crime
+ longitudnal
- individual differences
seasonal affective disorder
shows seasonal changes in mood and behaviour
usually during winter months
terman et al- SAD research
procedure
124 participants between 18+65 with SAD
study lasted 3 weeks
3 conditions
condition a- exposed to a bright light box every morning for 30 mins. Improved symptoms 60%
condition b- exposed to a light box every evening for 30 mins. improved symptoms 30%
condition c- 30 mins every morning in front of a negative ion generator box. improved symptoms 5%
evaluation of Terman et al
+ practical treatments- phototherapy, real life applications
resultd have been replicated by eastman
larger sample size over long period
- longitudinal-drop out
individual differences
temporal validity outdated
other factors may have cause SAD
ultradian rhytms
less than 24 hours
occurs frequently
EEG
EMG
EOG
records brain wave activity
records muscle movements
records eye movements
REM
NREM
REM- rapid eye movement sleep
NREM- none rapid eye movement sleep
NREM/REM sleep cycle
5 stages lasting about 90 minutes.
1-4: NREM
stage 5: REM
stages 1-2 are light sleep
stages 3-4 are deep sleep called slow wave sleep (sws)
body psychological “repair work” is done in sws and important biochemical processes occur
stage 5- REM, EEG activity resembling the awake brain
