Biopsychology Booklet 4 - Biological Rhythms

Question 1

What is a biological rhythm?

Answer 1

A pattern of change in the body that occurs in cycles and repeats

Question 2

What are the three types of biological rhythms?

Answer 2

Ultradian, Circadian and Infradian

Question 3

How long do Infradian Rhythms last, what are some examples?

Answer 3

Infradian rhythms last longer than 24 hours, some examples are:
-Female menstrual cycle
-Hibernation (in animals)

Question 4

How long do Ultradian rhythms last, what are some examples?

Answer 4

Ultradian rhythms are shorter than 24 hours, some examples are:
-Sleep cycle, this repeats every 90 minutes

Question 5

How long do Circadian rhythms last, what are some examples?

Answer 5

Circadian rhythms are cycles that last approximately one day, examples are:
-Body temperature
-Sleep-wake cycle

Question 6

What Infradian Rhythm example is recommended to use?

Answer 6

Menstrual cycle

Question 7

What Circadian Rhythm example is recommended to use?

Answer 7

Sleep-wake cycle

Question 8

What Ultradian Rhythm example is recommended to use?

Answer 8

Sleep cycle

Question 9

How can the Infradian Rhythm menstrual cycle be described?

Answer 9

It is governed by monthly changes in hormone levels which regulate ovulation and usually takes about 28 days to complete. During each cycle, oestrogen causes the ovary to develop an egg and release it, after ovulation progresteron helps the womb lining grow thicker preparing body for pregnancy. If Woman not pregnant the lining sheds

Question 10

How can the Circadian Rhythm Sleep-Wake cycle be described?

Answer 10

It dictates when humans should be asleep and awake, for most people this involves being awake during day and sleeping at night. Affected by both endogenous pacemakers and Exogenous Zeitgebers.

Question 11

How can the Ultradian Rhythm sleep cycle be described?

Answer 11

Research shows we go through 5 stages of sleep that last about 90 minutes in total, cycle continues through the night and can be investigated through EEG

Question 12

What are the influences of endogenous pacemakers and exogenous zeitgebers on the menstrual cycle?

Answer 12

Research suggest they’re heavily influenced by exogenous zeitgebers

Question 13

What was found in McClintock study?

Answer 13

29 women with irregular periods studied, samples of pheromones collected from 9 women at different times, pheromones rubbed on lip of other participants. 68% of women experienced changes to their cycle, made them closer to the cycle of their donor

Question 14

What are stages 1 and 2 of the sleep cycle?

Answer 14

Light sleep - A person is easily woken, alpha waves at the beginning and brainwave patterns become slower and more rhythmic. As sleep becomes deeper become theta waves

Question 15

What are stages 3 and 4 of the sleep cycle?

Answer 15

Deep sleep, involves delta waves which are slower still. This is slow wave sleep and difficult to wake someone up

Question 16

What are stages 5 sleep?

Answer 16

REM sleep, when body is paralysed but brain activity speeds up to awake levels. Eyes move around under eyelids and correlated with dreaming

Question 17

What are Endogenous Pacemakers?

Answer 17

The internal mechanisms that effect the body

Question 18

What are Exogenous Zeitgebers?

Answer 18

External cues that affect the body

Question 19

What is important to note about endogenous pacemakers and exogenous zeitgebers?

Answer 19

They work together and interact with each other

Question 20

What are the effects of endogenous pacemakers on the sleep/wake cycle?

Answer 20

One endogenous pacemaker is the Suprachiasmatic nucleus (SCN), a small bundle of nerve cells in the hypothalamus in each hemisphere of the brain

Question 21

Where is the SCN found?

Answer 21

Just above the place where the optic nerves from each eye cross over

Question 22

What info does the SCN receive?

Answer 22

Info about light from area near the eyes

Question 23

What is the SCN affected by?

Answer 23

External cues such as light and dark but also internal activity rhythm that persists when isolated from the rest of the brain

Question 24

What is the SCN an example of?

Answer 24

How endogenous pacemakers (SCN) interact with exogenous zeitgebers (Light) to control circadian rhythms

Question 25

What does the SCN do with information it receives about light ?

Answer 25

Passes it on to the pineal gland, which is a pea like structure behind the hypothalamus

Question 26

What does the pineal gland do during the night?

Answer 26

Converts the neurotransmitter serotonin into melatonin

Question 27

What does melatonin do?

Answer 27

Makes us feel less alert and more sleepy

Question 28

What was the procedure in study DeCoursey et al (2000)

Answer 28

He destroyed the SCN connections in the brain of 30 chipmunks who were then returned to their natural habitat and observed for 80 days

Question 29

What were the findings of DeCoursey et al?

Answer 29

The sleep/wake cycle on the chipmunks disappeared and by the end of the study many had been killed

Question 30

What was concluded from DeCoursey et al?

Answer 30

Shows how important the SCN is in establishing circadian rhythms and that with absence of the endogenous pacemaker, exogenous zeitgebers are not enough to regulate body rhythms

Question 31

What are two exogenous zeitgebers that affect the sleep/wake cycle?

Answer 31

-Light
-Social Cues

Question 32

What is the most commonly accepted view on endogenous pacemakers and exogenous zeitgebers?

Answer 32

EP interact with EZ to ensure we are synchronised with the outside world

Question 33

What is free running?

Answer 33

Circadian rhythms are capable of this, where without influence of external cues at all, the SCN will run to a rhythm of about 25 hours.

Question 34

What is the process of the internal biological clock being adjusted to external cues called?

Answer 34

Entrainment

Question 35

What was found in study Michael Siffre

Answer 35

He spent 6 months underground in a cave where he deprived himself of light and sound. Cut off from EZs. His sleep/wake cycle settled to around 25 hours.

Question 36

What was found in study Campbell and Murphy?

Answer 36

They applied light to the back of the knees of 15 participants, this resulted in a shit of the participants sleep/wake cycle of up to hours in some cases.

Question 37

What are the evaluations of circadian rhythms?

Answer 37

😁Research to support: Michael Siffre
😁Research to support: Campbell and Murphy
😁Practical Application: Shift Workers
😭Methodological issues
😭Individual differences

Question 38

What was discovered in the Dement and Kleitman study?

Answer 38

EEGs used to measure sleep patterns of 9 participants. Found that REM activity was highly correlated with dreaming. Showing that there must be different stages of sleep, as each stage has its own unique brain wave and these repeat every 90 minutes

Question 39

What are the evaluations of Ultradian and Infradian Rhythms?

Answer 39

😁Dement and Kleitman
😁Treatments for Insomnia
😭Yank and Schank
😭Methodological issues
😭Individual differences

Question 40

What was found in study Yank and Schank?

Answer 40

186 chinese women living in university halls over a year, no evidence of cycles becoming synced.