biological rythms: circadian rhythms

Question 1

what is a biological rhythm governed by

Answer 1

-body’s internal clock (endogenous pacemakers )
-external environment changes (exogenous zeitgebers )

Question 2

what are circadian rythms

Answer 2

-last around 24hrs
-e.g sleep/wake cycle and core body temp

Question 3

what exogenous zeitgebers affect sleep wake cycle

Answer 3

-daylight
-drowsy at night and alert in day

Question 4

what endogenous pacemaker affects sleep wake cycle

Answer 4

-SCN
-provides information from the eye about light
-exogenous zeitgebers may affect SCN

Question 5

what was siffre’s cave study

Answer 5

-periods of time spent underground to study effects on his own biological rythms
-deprived from natural light and sound
-2months in cave
-free running biological rythm settled down to one that was just beyond 24 hrs (25)
-didn’t contunie to fall asleep and wake up at regular cycle

Question 6

what was the research carried out by ashcoff and wever

Answer 6

-Ps spent time in bunkers (no natural light)
-one Ps sleep wake cycle extended to 29hrs
-suggests natural sleep wake cycle may be slightly longer than 24hrs but entrained by exogenous zeitgebers e.g daylight and mealtimes

Question 7

what did folkard study?

Answer 7

-studied zeitgebers on our biological clock
-12 ppl lived in dark in cave for 3 weeks
-going bed at 11:45 and waking at 7:45
-eventually researchers speeded clock without Ps knowledge so the day became 22hrs
-only one Ps adjusted to regime
-so we have strong free running circadian rythm that can’t be overridden by exo zeitgebers

Question 8

what are the strengths

Answer 8

(shift work)
-tells u adverse effects of when circadian rythms are disrupted
-night workers had less concentration at 6am
- meaning more mistakes and accidents
-also pinpointed relation between shift work and poor health e.g heart issue
- real world implications to better work productivity

(medical treatment)
-led to the field of chromotherapuetics
producing medical treatment corresponding to biological rhythms
-e.g aspirin for heart attacks most effective at night
- heart attacks likely in the morning so timing is key

Question 9

weaknesses?

Answer 9

(counterpoint shift work)
-use corelational methods
-so hard to establish if desynchronisation of sleep wake cycle is cause of negative effects
- may be other factors
-solomon found high divorce rates in shiftworkers may be due to deprived sleep and missing out on family events
-may not only be down to biological factors

-(individual differences)
-generalisations are hard to make
-based on small samples that vary from person to person
duffy et al found that some people have natural preference for going bed early or rising early
-siffre observed his sleep wake cycle slow down since he was a young man
- difficult to discuss anything more than averages

Question 10

what did wolfson recommend ab school days?

Answer 10

-start a couple hours later
-hormonal factors mean it’s harder for teens to get to sleep at night and they feel more sleep at the start of the school day
-later starts reduce dependence on caffeine

Question 11

what are the weaknesses of starting school later?

Answer 11

-disrupts teachers and parents
-limits extra curricular clubs after school
-teens may js simply stay up later and still be exhausted