[S] Biological rhythms

Question 1

What is a biological rhythm?

Answer 1

An innate, biologically driven behaviour that is periodically repeated.

Question 2

What does the hypothalamus do?

Answer 2

It influences our sense of time, and produces melatonin when it gets dark.

Question 3

What does seasonal affective disorder do?

Answer 3

Affect a person’s melatonin production, producing more than necessary which makes them feel drowsy and exhausted.

Question 4

What are exogenous zeitgebers?

Answer 4

External time-givers such as clocks.

Question 5

What are endogenous pacemakers?

Answer 5

Internal cues such as hormones.

Question 6

What are the four main types of biological rhythms?

Answer 6

Ultradian, circadian, infradian and circannual.

Question 7

What is an ultradian rhythm?

Answer 7

A rhythm that spans less than and occurs more than once in a day, such as the sleep cycle.

Question 8

What is a circadian rhythm?

Answer 8

A rhythm that lasts around 24 hours, such as the sleep/wake cycle.

Question 9

What is an infradian rhythm?

Answer 9

A rhythm that lasts for more than a day but less than a year, such as the menstrual cycle.

Question 10

What is a circannual rhythm?

Answer 10

A rhythm that occurs around once a year, such as the migration of birds.

Question 11

What did Dement and Kleitman find?

Answer 11

People awoken in REM sleep were more likely to report that they were dreaming.

Question 12

What did Friedman and Fisher find?

Answer 12

The Basic Rest Activity Cycle is a 90 minute cycle in eating and drinking behaviour.

Question 13

What is a strength of research into ultradian rhythms?

Answer 13

There is a link between REM sleep and dreaming.

Question 14

What is a weakness of research into ultradian rhythms?

Answer 14

Dement’s research was conducted in a laboratory so the results could have been affected.

Question 15

What did Siffre find?

Answer 15

After spending 6 months living in a cave with no natural light, his sleep/wake cycle adjusted to 25 hours.

Question 16

What did Aschoff and Wever find?

Answer 16

Participants placed in a WWII bunker without exogenous zeitgebers maintained a 24-25 hour sleep cycle.

Question 17

What did Czeisler et al find?

Answer 17

24 men and women who lived in very subdued light could have their circadian rhythms lowered to 22 hours and extended to 28 hours.

Question 18

What did Miles et al find?

Answer 18

A blind man had a circadian rhythm of 24.9 hours and exogenous zeitgebers had little effects on his rhythms and he had to take sedatives and stimulants in order to maintain a healthy rhythm.

Question 19

What did Morgan find?

Answer 19

Bred mutant hamsters who to have a circadian rhythm of 20 hours and transplanted their suprachiasmatic nucleus to normal hamsters who then displayed the mutant rhythms.

Question 20

What is a strength of research into ultradian rhythms?

Answer 20

There is lots of research, all supporting the same ideas making the theory more reliable.

Question 21

What are two weaknesses of research into ultradian rhythms?

Answer 21

1. Research is based on case studies.

2. Animal studies are unethical.

Question 22

What did Russell et al find?

Answer 22

When several women live together and do not take contraceptives, their menstrual cycles synchronise.

Question 23

What is a strength of research into infradian rhythms?

Answer 23

Russell’s study shows that biological rhythms can be controlled by exogenous cues.

Question 24

What is a weakness of research into infradian rhythms?

Answer 24

Focuses on females.