The Restoration Theory of Sleep
The function of sleep is to allow the body to be repaired/ restored.
The body wants homeostasis, maybe sleep helps achieve this?
Hartmann (1973) said that REM sleep is a time for making neurotransmitters to compensate for the amount used during the day.
Stern and Morgane (1974) also thought that that REM sleep allows the brain to restore levels of neurotransmitters to 'factory settings'.
Oswald (1980) claimed that NREM sleep restored the body and REM sleep restored the brain, through protein synthesis and that Slow Wave Sleep (SWS) helped the body restore itself. BUT … for protein synthesis you need amino acids from diet and unless you eat just before you sleep, your levels would be too low for this to occur.
Horne (1988), distinguished between core (SWS & REM) sleep and lighter (stages 1 to 3) sleep as far as restoration goes – need more SWS & REM if sleep deprived. Brain rather than body affected if sleep deprived.
Fatal familial insomnia
Rare inherited condition. Sleep normally till middle age then just stop. Usually die within 2 years. Linked to damage to thalamus, this might be what causes death rather than sleep deprivation
Lots of exercise makes people fall asleep faster but they don’t sleep for longer. (Breedlove et al ’07)
Shapiro ’81: athletes aged 18-26 did an ultra-marathon (92K), sleep recorded for next 4 nights. Found they slept 1 ½ hrs longer the next 2 nights, and had more deep sleep (stage 4), 45% compared to 25% normally. Suggests the body uses sleep to recover.
BUT … lack of exercise doesn’t seem to make you…