✓ Circadian Rhythms (AO1)

Question 1

What are Biological Rhythms?

Answer 1

all living objects are subject to biological rhythms; things that control the bodily functions/ systems

biological rhythms are controlled by endogenous pacemakers (internal clocks) & exogenous zeitgebers (external cues)

Question 2

What are the 3 (main) Biological Rhythms?

Answer 2

Circadian
Infradian
Ultradian

Question 3

What are Circadian Rhythms?

Answer 3

biological rhythms which occur in around a 24 hour cycle (e.g. the sleep/wake cycle & core body temperature)

Question 4

What is the Exogenous Zeitgeber in the sleep/wake cycle?

Answer 4

daylight - it makes us feel awake in the light & sleepy when dark

Question 5

What was Siffre’s Cave study?

Answer 5

Siffre spent 2 months in the caves of the Alps, away from all natural light

body clock extended due to lack of external cues (light); his sleep/wake cycle was around 25 hours instead

when he emerged he thought the date was a month earlier than it was

Question 6

What was Aschoff & Wever’s study?

Answer 6

group of ppts spent 4 weeks in a WW2 bunker, deprived of natural light

all but one displayed a circadian rhythm of 24-25 hours

Question 7

What does Aschoff & Wever + Siffre’s studies suggest?

Answer 7

both A&W + S’s research suggest that the innate sleep/wake cycle sits at around 25 hours but is entrained by external cues

Question 8

What was Folkard et al’s study?

Answer 8

12 ppts in a dark cave for 3 weeks, going to bed when the clock said 11:45 pm & waking when it said 7:45 am

gradually researchers sped up the clock so that the apparent 24 hour period actually only lasted 22 hours

only 1 of the ppts comfortably adjusted to the regime

Question 9

What does Folkard et al’s study suggest?

Answer 9

suggests that our endogenous pacemaker for the sleep/wake cycle is strong & not easily overridden by external cues