ened from stage 1 sleep and sudden muscle contractions called hypnic myoclonia may be experienced (NINDS, 2003).
Around 50 percent of total sleep time is spent in stage 2 sleep. When entering stage 2 sleep, eye movements stop and brain waves become slower, with occasional bursts of rapid waves called sleep spindles (NINDS, 2003).
In stage 3, extremely slow brain waves called delta waves begin to appear, which are interspersed with smaller, faster waves. Around 3 to 8% of time is spent in stage 3 (NINDS, 2003).
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