Ultradian Rhythms

Question 1

what are ultradian rhythms?

Answer 1

frequency of more than one cycle in 24 hours

Question 2

give an example of an ultadian rhythm

Answer 2

stages of sleep - sleep occurs in 90 minute periods (ie. more than one cycle in 24 hours)

Question 3

what are the five stages of sleep?

Answer 3

• stages 1 & 2: light sleep
• stages 3 & 4: difficult to arouse someone
• stage 5: REM (rapid eye movement)

Question 4

what happens during stage 1 & 2?

Answer 4

• brainwaves become slower and more rhytmic (alpha waves)
• they slow further as sleep becomes deeper (beta waves)

Question 5

what happens during stages 3 & 4?

Answer 5

deep sleep characterised by delta waves which are slower still

Question 6

what happens during stage 5?

Answer 6

• fast, jerky activity of eyes.
• body paralysed yet brain activity speeds up.

Question 7

outline Dement and Kleitman (1957) study of the stages of sleep?

Answer 7

they monitored the sleep patterns of 9 participants in a sleep lab

Question 8

what did D&K (1957) find out about REM?

Answer 8

• REM acvtivity during sleep correlated with dreaming
• brain activity varied according to how vivid dreams were
• participants woken during dreaming reported accurate recall of their dreams

Question 9

what does D&K (1957) study suggest and why is this a strength?

Answer 9

1. REM sleep is a distinct ultradian rhythm and an important component of the ultradian sleep cycle
2. it provides qualative evidence for the different stages of sleep

Question 10

how studied the stages of sleep and what date was their study?

Answer 10

dement and kleitman (1957)