The stages and cycle of sleep. PSYA3. AQA.

The stages and cycles of sleep as according to the AQA specification for PSYA3.

Taken from my 2013 notes.

HideShow resource information

Stage 1

  • Lasts approximately 15 mintues.
  • The EEG levels are characterised by theta waves.
  • EOG indicates rolling eye movements.
  • EMG shows reductions in muscle tension.
  • Heart rate and temperature fall.
  • A hypnogogic state may occur, causing hallucinations e.g myclonic jerks.
  • The lightest stage of sleep and we are easily awakened.
1 of 5

Stage 2

  • Lasts approximately 20 minutes.
  • EEG activity is characterised by larger and slower theta waves and short bursts of high frequency sleep spindles.
  • EOG shows little eye movement.
  • EMG shows the muscles are relaxed.
  • K-complexes also occur; our response to external and internal stimuli.
  • It is still easy to be awakened.
2 of 5

Stage 3

  • Lasts approximately 15 minutes.
  • EEG activity is characterised by long, slow delta waves with some sleep spindles.
  • The EOG and EMG are the same as stage 2.
3 of 5

Stage 4

  • Lasts approximately 30 minutes.
  • Also known as slow wave sleep (SWS) because of the long, slow delta waves of the EEG.
  • This is deep sleep so it is hard to wake someone from.
  • Body temperature, heart rate and blood pressure drops to their lowest point.
  • Growth hormones are secreted.
  • The stage when parasomnias, such as sleep-walking and night terrors occur.
4 of 5

Stage 5 (REM)

  • Lasts approximately 10 minutes in the 1st cycle and builds up to an hour by the 4th and 5th cycles.
  • EEG activity is characterised by beta waves, which also occur during a relaxed waking state.
  • This high level of brain activity is linked to dreaming.
  • Also been called paradoxical sleep because of the EEG readings show that the brain is very active, whilst the EMG readings show that the body is paralysed.
  • It is the hardest sleep to wake someone from, as the paralysis prevents us from acting out our dreams.
5 of 5

Comments

No comments have yet been made

Similar Psychology resources:

See all Psychology resources »See all Sleep resources »