Stage 2 - eye movement stops and brain waves become slower, with occasional bursts of rapid waves called sleep spindles. This stage forms 45-55% of total sleep.
Stage 4 - the brain produces delta waves almost exclusively. It is very difficult to wake someone during stages 3 and 4, which together are called "deep sleep.
People awakened while in deep sleep do not adjust immediately and often feel groggy and disoriented for several minutes after they wake up.Forms 12-15% of sleep
Stage 5 - REM - breathing becomes more rapid, irregular and shallow, eyes jerk rapidly in various directions, and limb muscles become temporarily paralyzed.
Stage 1 - light sleep, eyes move slowly, and muscle activity slows. This stage forms 4-5% of total sleep.
Stage 2 - eye movement stops and brain waves become slower, with occasional bursts of rapid waves called sleep spindles. This stage forms 45-55% of total sleep.
Stage 3 - extremely slow brain waves called delta waves begin to appear, interspersed with smaller, faster waves. 4-6% of total sleep
Stage 4 - the brain produces delta waves almost exclusively. It is very difficult to wake someone during stages 3 and 4, which together are called "deep sleep.
There is no eye movement or muscle activity.
People awakened while in deep sleep do not adjust immediately and often feel groggy and disoriented for several minutes after they wake up.Forms 12-15% of sleep
Stage 5 - REM - breathing becomes more rapid, irregular and shallow, eyes jerk rapidly in various directions, and limb muscles become temporarily paralyzed.
Heart rate increases, blood pressure rises, and males develop penile erections.
When people awaken during REM sleep, they often describe bizarre and illogical tales - dreams. Forms 20-25% of total sleep time.