Ultradian rhythms

• What is an example of an ultradian rhythm?

  Stages of sleep
• How long does each stage of sleep last?

  90 minutes
• What is each stage of sleep characterised by?

  Different level of brainwave activity
• How can different levels of brainwave activity from each stage of sleep by monitored?

  EEG
• Stage 5

  Paralysed but brain activity resembles awake brain - produces theta waves and eyes move around; dreams most frequent
• Stage 5


  Paralysed but brain activity resembles awake brain - produces theta waves and eyes move around; dreams most frequent
• What is stage 5 of the sleep cycle also known as?

  REM sleep
• What does the brain produce during stage 5 of the sleep cycle?

  Theta waves
• What stage are dreams most frequently experienced?

  5
• What does REM stand for?

  Rapid Eye Movement
• Why is stage 5 also known as REM sleep?

  Eyes occasionally move around
• What happens to the body in stage 5 of the sleep cycle?

  Paralysed
• What does brain activity resemble in stage 5 of the sleep cycle?

  Awake brain
• What are stages 3 and 4 of the sleep cycle also known as?

  Deep sleep or SWS sleep
• What does SWS stand for?

  Slow wave sleep
• Stages 3 and 4

  Brain waves delta waves with lower frequency and higher amplitude - hard to wake someone up
• Stages 3 and 4


  Brain waves delta waves with lower frequency and higher amplitude - hard to wake someone up
• What are the brain waves in stages 3 and 4 of the sleep cycle?

  Delta waves with lower frequency and higher amplitude
• What is it difficult to do during stages 3 and 4 of the sleep cycle?

  Wake someone up
• Stage 1


  Light sleep - easily woken; alpha waves with high frequency and short amplitude
• Stage 1

  Light sleep - easily woken; alpha waves with high frequency and short amplitude
• What are the brain waves during stage 1 of the sleep cycle?

  Alpha waves with high frequency and short amplitude
• Stage 2


  Alpha waves continue - sleep spindles happen
• Stage 2

  Alpha waves continue - sleep spindles happen
• What are sleep spindles?

  Random changes in activity