AQA PSYA3 - Biological Rhythms - Restoration Theory of Sleep

Restoration Theory

States that the function of sleep is to restore physiological systems that are active in the day time - especially the brain. Two restoration theories are Oswald and Horne.

Oswald, (1980)

States that REM is for restoration of the brain and NREM is for restoration of the body

• Evidence for: 
  • Damage to the brain results in an increase in the amount of REM
  • Skin cells grow more quickly in NREM
  • Growth hormone is secreted during SWS.
  • Marathon runners have more NREM after a race (Shapiro et al 1981)
  • Babies spend more time in REM (brains are developing) and release more growth hormone in SWS (bodies are growing rapidly).
• Evidence against:
  • Horne and Minardi (1985) found that we fall asleep faster after exercise, but do not sleep for longer.
  • Body repair in NREM would depend on nutrients from evening meal, however they're only available for 6 hours after eating.

Horne (1998)

States that both REM and stage 3 & 4 of NREM (SWS) are for brain restoration.

He also suggests that REM and SWS NREM make up 'core sleep', and that light NREM is 'optional sleep', with the…