- Okai (1992) studied REM and NREM of unborn babies of 30 pregnant women.
- By 32 weeks REM could be identified.
- This correlates with development of neural structures in the brain which are known to be responsible for sleep stages.
- Spend an average of 16 hours sleeping per day.
- Shorter cycle than adults.
- Have 2 sleep stages; quiet sleep and active sleep.
- These are immature versions of SWS and REM.
- In first months sleep is equally divided between the two.
- By 6 months a circadian rhythm is established.
- By 1 year infants sleep mainly at night.
- SWS lengthens and REM reduces.
- 5 years: have adult EEG pattern, but sleep 12 hours per day. Sleep is 30% REM.
- Boys sleep more than girls.
- Need for sleep gradually decreases.
- Sleep increases to 10 hours per day.
- Circadian rhythm changes; feel more awake at night, find it difficult to wake up early (phase delay).