Biological rhythms: circadian rhythms Flashcards
1
Q
What are biological rhythms?
A
- pattern of changes in the body that follow cyclical time periods
- influenced by internal body clocks
- influenced by environmental changes
2
Q
What are endogenous pacemakers?
A
- the bodys internal biological body clocks
3
Q
What are exogenous zeitgerbers?
A
- external changes to the environment
4
Q
What are circadian rhythms?
A
- rhythms that last around 24 hours
- sleep/wake cycle
- core body temperature
5
Q
what is the suprachiasmatic nucleus (SCN)?
A
- endogenous pacemaker that governs the bodys sleep/wake cycle as it is a biological clock
- lies above the optic chasm and provides info from the eye about light
- exogenous zeitgerber (light) can reset the SCN
6
Q
Siffre’s cave study (1962)
A
- spent several extended periods underground to see the effect on his biological rhythm
- surfaced in mid-sept after two months but thought it was mid-aug
7
Q
Siffre’s second cave study: texan cave
A
- spent 6 months in a texan cave
- his ‘free running’ biological rhythms settled to 25 hours but with falling asleep and waking up on a regular schedule
8
Q
Aschoff and wever: WW2 bunker research
A
- convinced pp to spend 4 weeks in bunker deprived of natural light
- all but one participants had circadian rhythms of 24 or 25 hours
- suggested the natural sleep/wake cycle lasted slight longer than 24 hours but was entrained by exogenous zeitgerbers of a 24 hour day
8
Q
Folkard (1985): dark cave study
A
- 12 people lived in a dark cave for three weeks
- going to bed when clock said 11:45 and waking up when the clock said 7:45
- they gradually sped up the clock so 24 hours was actually just 22
- one pp could adjust
- strong circadian rhythm cant be over ridden by exogenous zeitgerbers
8
Q
Evaluation limitation: counterpoint to shift work (correlational)
A
- studies use correlational methods
- other factors may cause desynchronisation
- solomon found high divorce rates could be due to less sleep and missing out on family events
- biological factors may not cause consequences associated with shift work
8
Q
Evaluation strength: shift work
A
- able to understand consequences of disrupted circadian rhythms
- night shift workers have reduced concentration at around 6 am = mistakes
- shift workers have poorer health
- helps manage worker productivity
8
Q
Evaluation strength: medical treatment
A
- coordinate many bodily processes e.g. hormone levels HR and digestion
- these rise and fall so there has been resreach into how medicine can be administered to fit someones biological rhythm e.g. aspirin
- help increase effectiveness of drug treatments
8
Q
Evaluation limitation: individual differences
A
- hard to make generalisations
- studies were done on small samples
- found sleep/wake cycles can vary from 13-65 hours
- Duffy et al. found people have natural preference for waking or sleeping early
- hard to use data to discuss anything more than averages
