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.
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.
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…