Circadian rhythms Flashcards Preview

Biopsychology AS/A2 AQA > Circadian rhythms > Flashcards

Flashcards in Circadian rhythms Deck (30)
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1
Q

What two things govern biological rhythms?

A

Exogenous zeitgeibers

Endogenous pacemakers

2
Q

What are exogenous zeitgeibers?

A

External changes in the environment

3
Q

What are endogenous pacemakers?

A

The body’s biological internal clock

4
Q

What is a circadian rhythm?

A

A rhythm that occurs that last within the 24 hour cycle

5
Q

What is an example of a circadian rhythm?

A

Sleeping

6
Q

What is daylight and what is the effect of it?

A

Exogenous Zeitgeiber

Causes people to feel awake during the day and drowsy at night time

7
Q

When is core body temperature at the lowest?

A

At around 4am

36 degrees

8
Q

When is core body temperature at the highest?

A

at around 6pm

38 degrees

9
Q

What does evidence suggest about the effect of body temperature?

A

It affects mental abilities, suggesting that the warmer we are the better our cognitive performance

10
Q

What did Folkard et al (1977) find?

A

Children who had stories read to them at 3pm had significantly better recall and comprehension after a week compared to children who heard the same story at 9am

11
Q

What did Gupta (1991) find?

A

Improved performance on IQ tests when participants were assessed at 7pm as opposed to 2pm and 9am

12
Q

Outline Sieffre’s cave study (1962)?

A

He spent 2 months in a cave in July and resurfaced in mid September, believing it was mid August.
He was deprived of exposure to natural light and sound but had access to adequate food and drink

13
Q

What were the results of Sieffre’s cave study? (1962)

A

His free-running body clock settled at a little longer than the normal 24 hours.
He slept and woke at regular intervals.

14
Q

What conclusions can be drawn from Sieffre’s cave study (1962)?

A

We have a very strong internal body clock which is hard to deviate from

15
Q

What are some evaluative points for Sieffre’s study? (1962)

A
  • He had poor control
  • He carried it out again at age 60 but when you get older your internal body clock is slower anyways so age is then a confounding variable
16
Q

Outline Aschoff and Wever (1976)?

A

They had a group of participants spend 4 weeks in a WW2 bunker, deprived of natural light.

17
Q

What were the results for Aschoff and Wever’s study? (1976)

A

Everyone except 1 person had a 24 hour or 25 hour cycle.

18
Q

What conclusions can be drawn from Aschoff and Wever’s study? (1976)

A

Suggests that our cycle may be longer than 24 hours but this is entrained with exogenous zeitgeibers

19
Q

What evaluative points can be made about Aschoff and Wever’s study? (1976)

A
  • Poor control
  • They used artificial light which they assumed wouldn’t affect the results but studies have shown that it does and therefore acts as a confounding variable
20
Q

Outline Folkard et al’s study (1985)?

A

Had 12 people spend 3 weeks in a cave.
They all went to bed when it was 11pm and work at 7.45. Researchers gradually sped up the clock until it was just a 22 hour clock

21
Q

What were the results of Folkard et al’s study? (1985)

A

The participants were unable to adjust to the 22 hour clock

22
Q

What conclusions can be drawn from Folkard et al’s study? (1985)

A

We have strong circadian rhythms

23
Q

What is a practical application for research into circadian rhythms? (SW)

A
  • Shift workers
  • There is a reduced concentration a 6am
  • known as a circadian trough
  • Economical implications - worse work produced at 6am
24
Q

What did Boven (1996) find relating to shift work?

A

Found that 6am was the time that mistakes and accidents were more likely to occur

25
Q

What did Knutsson (2003) find?

A

People who work shifts are 3 times more likely to develop heart disease due to stress

26
Q

What do findings about shift work suggest should be changed?

A

The timing of shifts to maximise the efficiency of the individuals and reduce accidents

27
Q

What is a practical application for research into circadian rhythms? (DT)

A
  • Drug treatments
  • Rhythms affected by heart rate, digestion and hormone levels
  • Has an effect on pharmokinetics which is the action of drugs on the body and how well they are absorbed and disturb distributed throughout the day
  • Certain peak times during the day or night when drugs are likely to be at their most effective - led to guidelines of timings of drugs
28
Q

What is the issue with the use of case studies and small samples for research into circadian rhythms.

A

it means it is harder to generalise the findings

Not representative of the whole population

29
Q

What is the issue with individual differences when looking at circadian rhythms?

A

Individual samples may vary from 30-65 hours.

30
Q

What did Duffy et al find?

A

That some people have a natural preference to go to bed early or go to bed late