Bio Psych RYTHMNS Flashcards
(9 cards)
what is a circadian rythmn
a biological rythmn that lasts about 24 hours
what does a circadian rythmn do
regulate several bodily processes such as the sleep wake cycle and core body changes in temp
what is a01 for the sleep wake cycle
its controlled by the SCN in the hypothalamus, lightness and darkness dictate when we sleep, our strongest sleep drive is between 2-4am and 1-3pm, the free running internal clock maintains a cycle of 24-25 hours even in absence of light
what is the a01 of core body temperature
one of the best indicators of the circadian rythmn, its at its lowest at 4:30 and at its highest at 6pm, sleep occur when the core body temp drops,a small drop in body temp occurs around 2-4pm which explains why we feel sleepy in the afternoon
what was the study for circadian rythmns
siffre isolated himself from light for 6 months spending his time in a cave with only artifical light, he had no clock but had verbal contact with the outside world
what was found in this study
his internal bodyclock was allowed to free run and it eventually settled into a sleep wake cylce of 25 hours
what does this suggest about the circadian rythmn
in the absence of an exogenous zeitgeber, circadian rythmns are roughly maintained supporting the existence of an internal body clock- the sleep wake cycle is 24 hours
what does it also suggest
exogenous zeitgebers are vital to keeping an individual to a 24 hour sleep wake cycle and therefore endegenous pacemakers and exogenous zeitgebers work together
what is the A03 for this study
Case study-unrepresentative
artifical light affects sleep wake cycle-czeslier et al managed to change pps SWC to 22 hours using artificial light
individual differences in
cycle length- cszeliar et al found the sleep wake cycle varied in some cases from 13-65 hours. some people have a preference for sleeping and rising early-others dont.
