ULTRADIAN RHYTHMS

Question 1

● What is an ultradian rhythm?

Answer 1

A biological rhythm that occurs more than once every 24 hours

Question 2

● Give one example of an ultradian rhythm.

Answer 2

Sleep cycle

Question 3

● How long is one full cycle of sleep?

Answer 3

90 minutes

Question 4

● How many stages of sleep are there?

Answer 4

5

Question 5

● What type of brain wave is seen in deep sleep?

Answer 5

Delta waves

Question 6

● What is the fifth stage of sleep called?

Answer 6

REM

Question 7

● What does REM stand for?

Answer 7

Rapid Eye Movement

Question 8

● What brain waves are seen in REM sleep?

Answer 8

Theta waves

Question 9

● What brain wave is seen in light sleep?

Answer 9

Alpha waves

Question 10

● What does EEG stand for?

Answer 10

Electroencephalogram

Question 11

▲ What happens in stage 1 and 2 of sleep?

Answer 11

Light sleep with alpha waves

Question 12

▲ What happens during stage 3 and 4 of sleep?

Answer 12

Deep sleep with delta waves

Question 13

▲ What occurs during stage 5 (REM)?

Answer 13

Brain is active, body is paralysed, dreaming occurs

Question 14

▲ How is the brain studied during sleep?

Answer 14

Using EEG to measure electrical activity

Question 15

▲ What function does stage 4 serve?

Answer 15

Muscle repair

Question 16

▲ What function does stage 5 serve?

Answer 16

Replenishing neurotransmitters

Question 17

▲ Why is stage 5 called REM?

Answer 17

It involves rapid eye movements

Question 18

▲ What kind of rhythm is the sleep cycle?

Answer 18

Ultradian rhythm

Question 19

▲ Why is sleep cycle considered ultradian?

Answer 19

It repeats multiple times each night

Question 20

▲ What exogenous factor increases stage 4 sleep?

Answer 20

Exercise

Question 21

✪ How does research using EEG support the idea of ultradian rhythms?

Answer 21

It shows regular brain activity patterns in 90-minute cycles

Question 22

✪ Why does the use of EEG increase scientific credibility of ultradian rhythm research?

Answer 22

It uses objective, empirical data to measure brain activity

Question 23

✪ What is a limitation of sleep research using EEG?

Answer 23

It may reduce ecological validity due to artificial lab settings

Question 24

✪ How do mental health conditions affect ultradian rhythms?

Answer 24

Depression increases REM duration and starts it earlier

Question 25

✪ What impact does poor stage 4 sleep have in old age?

Answer 25

Leads to reduced alertness and less growth hormone

Question 26

✪ How has ultradian rhythm research been applied practically?

Answer 26

Used to develop treatments to increase stage 4 sleep in elderly

Question 27

✪ Why does the sleep lab setting reduce external validity?

Answer 27

It alters natural sleep patterns due to environment and equipment

Question 28

✪ How do exogenous factors influence ultradian rhythms?

Answer 28

They impact consistency and structure of sleep stages

Question 29

✪ Why is ultradian rhythm not purely endogenous?

Answer 29

Because external factors like exercise and mental health can influence it

Question 30

✪ Why is it difficult to generalise findings from sleep labs?

Answer 30

Artificial settings don't reflect real-life sleep patterns

Question 31

● What tool is used to measure sleep stages?

Answer 31

EEG

Question 32

● What happens to the body during REM sleep?

Answer 32

It becomes paralysed

Question 33

● What happens in stage 4 sleep?

Answer 33

Muscle repair

Question 34

● What stage of sleep is most associated with dreaming?

Answer 34

Stage 5 / REM

Question 35

● What is the average number of sleep cycles per night?

Answer 35

5

Question 36

▲ Why is stage 4 sleep important for athletes?

Answer 36

Aids muscle recovery

Question 37

▲ How does EEG data show the sleep cycle is rhythmic?

Answer 37

It reveals consistent brain wave patterns across cycles

Question 38

▲ What changes in brain activity indicate stage transitions?

Answer 38

Frequency and amplitude of waves

Question 39

▲ Why is REM considered paradoxical sleep?

Answer 39

Brain is active but body is paralysed

Question 40

▲ How can exercise alter sleep structure?

Answer 40

Increases time spent in deep sleep

Question 41

✪ How does EEG research validate the five-stage sleep model?

Answer 41

It identifies distinct wave patterns at each stage

Question 42

✪ Why does REM sleep differ from other stages?

Answer 42

It mimics wakefulness in brain activity while body remains still

Question 43

✪ How does depression affect sleep architecture?

Answer 43

Alters REM onset and increases its duration

Question 44

✪ What does increased REM in depression suggest about mental health?

Answer 44

It influences endogenous regulation of rhythms

Question 45

✪ Why might lab-based EEG studies lack generalisability?

Answer 45

Participants’ sleep may be influenced by unnatural conditions