Ultradian Rhythms

Question 1

what is an ultradian rhythm?

Answer 1

happens more than 24 hours

Question 2

how often do sleep patterns occur?

Answer 2

90 minute periods

Question 3

what happens during sleep stages 1 and 2?

Answer 3

light sleep, can be easily woken

brainwaves become slower and more rhythmic (alpha waves), slowing further as sleep becomes deeper (theta waves)

Question 4

what happens during sleep stages 3 and 4?

Answer 4

difficult to wake someone

deep sleep or slow wave sleep (SWS)

characterised by delta waves, which are slower and have a greater amplitude

Question 5

what happens during sleep stage 5?

Answer 5

REM (rapid eye movement) sleep

fast, jerky activity of the eyes

body paralysed, yet brain activity speeds up

research suggests REM activity during sleep is linked to dreaming

Question 6

what are hypnogogic dreams?

Answer 6

occur during stages 1 and 2 shortly after falling asleep

may experience the feeling of being out of control or we are falling

may wake up with a jolt (hypnic twitch) when we are sure we are about to hit the ground

Question 7

how is brainwave activity during sleep measured?

Answer 7

measured in sleep labs using an EEG

Question 8

what did Kleitman (1969) suggest?

Answer 8

a similar 90 minute rhythm cycle continues during waking hours (BRAC)

Question 9

what is Kleitman’s BRAC characterised by?

Answer 9

(basic rest activity cycle)

a period of alertness followed by a spell of physiological fatigue, occurring over 90 minute periods during the day

supported by students finding it hard to concentrate for longer than 90 minute periods

Question 10

what was Ericsson et al (1993)’s study?

Answer 10

evidence of BRAC:
in a study of prodigious violinists, he found the best performers tended to practice 3 sessions during the day, each session lasting no more than 90 minutes and a break in between to ‘recharge’

Question 11

what is a strength of research into ultradian rhythms?

Answer 11

Dement and Kleitman (1957) monitored the sleep pattern of 9 participants in a sleep lab and found evidence for stages of sleep, particularly REM sleep
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REM activity correlated with dreaming; brain activity correlated with dreaming; brain activity varied depending on vividness of dreams; participants woken during dreaming could accurately recall them