Biological Rhythms (Circadian Rhythms) Flashcards
what 4 things must we remember for circadian rhythms?
biological rhythms
sleep/wake cycle
siffre’s cave study
other research
what are biological rhythms?
distinct patterns of changes in body activity to cyclical time periods influenced by exogenous zeitgebers and endogenous pacemakers
what is a circadian rhythm?
a biological rhythms subject to a 24 hour cycle regulating a number of body processes such as sleep/wake cycle and changes in the core body temperature
who has biological rhythms?
plants animals and people
why 2 things are biological rhythms governed by?
body’s internal biological clock - endogenous pacemakers
changes in the environment - exogenous zeitgebers
what is the most important exogenous zeitgeber?
daylight and this is shown through how we feel drowsy when it’s night-time and alert during the day
what is ‘free-running?’
if the biological clock was left to it’s own devices without the influence of external stimuli such as light
who tried to answer the question of ‘free-running’ and conducted research?
Siffre
what dud Siffre do?
spent several extended periods underground to study the effect of his bio rhy
how long did he spend in first 2 studies in the cave?
- 2 months in the cave of the alps
- 10 years later, performed similar test for 6 months in a Texan cave
what happened in both of Siffre’s experiments?
‘free-running’ biological rhythm settled down to 25 hours though he did continue to fall asleep and wake on a regular schedule
who found similar results to Siffre?
Aschoff and Wever
what did Aschoff and Wever do?
ppts spent 4 weeks in WWII bunker w/ no natural light
what were the findings of Aschoff and Wever experiment?
all but 1 ppts had circadian rhythm of 25 hrs, one had 29 hrs
