Topic 9- Cicadian Rhythms

Question 1

PEEL 1
Individual differences

Answer 1

P- There’s individual differences in circadian rhythms
E- The cycks length can vary from 13 to 65.
E- Also, morning people prefer to rise early and go to bed early whereas evening people prefer to wake and go to bed later.
L- So, Individuals seem to have innate differences in their cycle length and onset.

Question 2

PEEL 2
Dim lights

Answer 2

P- There’s a limitation as earlier studies suffered.
E- As they assumed dim artificial light wouldn’t affect circadian rhythms.
E- Czeizler altered participants’ circadian rhythms down to 22 hours and up to 28 hours using dim artificial light alone.
L- This weakened the evidence of the earlier studies.

Question 3

PEEL 3
Body temp

Answer 3

P- The temperature may be more important than light in setting the body clock.
E- It seems the SCN transforms information about light levels into neural messages that set the body’s temperature.
E- Bohr found that fluctuations in body temp cause tissues to become active or inactive.
L- So, although the CNS responds to light, the circadian fluctuation of body temp may actually control other biological rhythms.