N1, 2 and 3 are non-REM stages of sleep, whereas N4 is REM sleep, where most dreams occur, each cycle takes around 90 minutes and repeats 4-5 times per night
Measured using EEGs, with theta and delta waves distinguishing sleep cycles
Stages of Sleep
N1 = Falling Asleep, Hypnic Jerks
N2 = Relaxed, heart rate and body temperature decrease
N3 = Deep sleep, heart rate at lowest
N4 = REM sleep, most dreams occur
(+) A03: Dermot + Kleitman
EEGs of 33 participants showing brain waves followed a cyclic activation pattern
Low = relaxed
High = REM
(+) A03: Haider
EEG of 10 recovering drug addicts had extended REM stages, showing that REM sleep is involved in brain recovery
(-) A03: Individual Differences
Differences between babies and adults REM stages
Babies = 80% REM
Adults = 20-25% REM
Adapts to the level of development needs the individual needs
