ultradian rhythms

Question 1

what are ultradian rhythms?

Answer 1

• occurs many times during the day

- e.g sleep cycle

Question 2

explain stages of sleep as an ultradian rhythm.

Answer 2

• sleep pattern occurs in 90-minute periods.

Question 3

what happens during stages 1 and 2 of sleep?

Answer 3

• light sleep so an individual may be easily woken.
• muscle activity slows down.
• breathing and heart rate slows down and a slight decrease in body temperature.
• brain waves becomes slower and more rhythmic (alpha waves), slowing further as sleep becomes deeper (theta waves).

Question 4

what happens during stages 3 and 4 of sleep?

Answer 4

• difficult to rouse someone.
• very limited muscle activity.
• rhythmic breathing occurs.
• deeper sleep or slow wave sleep characterised by delta waves which are slower still and have a greater amplitude.

Question 5

what happens during stage 5 of sleep?

Answer 5

• REM (rapid eye movement) sleep occurs.
• fast jerky activity of the eyes.
• body paralysed yet brain activity speeds up.
• muscles relax but heart rate increases.
• breathing is rapid and shallow.

Question 6

one strength on research into ultradian rhythms.

Answer 6

• evidence supports qualitatively different stages in sleep.
• Dement and Kleitman monitored the sleep patterns of 9 participants in a sleep lab and found evidence for REM.
• REM activity during sleep correlated wit dreaming and brain activity varied according to how vivid they were.
• participants woken up during dreaming reported accurate recall of dreams.
• suggests that REM sleep is an important component of the ultradian sleep cycle.

Question 7

one limitation on research into ultradian rhythms.

Answer 7

• there are individual differences in sleep stages.
• differences in sleep patterns of individuals are usually attributed to differences in non-biological factors e.g room temperature.
• this makes in difficult to generalise the results of studies to the wider population.