Sleep Stages and Benefits of Deep Sleep

Stage 1

The first stage of the sleep cycle is a transition period between wakefulness and sleep. During stage 1 sleep:

• Your brain slows down,
• Your heartbeat, your eye movements, and your breathing slow with it,
• Your body relaxes, and your muscles may twitch,

This brief period of sleep lasts for around five to ten minutes. At this time, the brain is still fairly active and producing high amplitude theta waves, which are slow brainwaves occurring mostly in the brain's frontal lobe.

Stage 2

People spend approximately 50% of their total sleep time during N.R.E.M stage 2, which lasts for about 20 minutes per cycle. During stage 2 sleep:

• You become less aware of your surroundings,
• Your body temperature drops,
• Your eye movements stop, and
• Your breathing and heart rate become more regular.

The brain also begins to produce bursts of rapid, rhythmic brain wave activity, which are known as sleep spindles. In this phase, memory consolidation takes place. Brain gathers, processes, and filters new memories acquired from the previous day. Body then slows down in preparation for N.R.E.M stage 3 sleep and R.E.M sleep, which are deep sleep stages.

Stage 3

Deep, slow brain waves known as delta waves begin to emerge during N.R.E.M stage 3 sleep. This stage of sleep is also called delta sleep. This is a period of deep sleep where any noises or activity in the environment may fail to wake the sleeping person. Getting enough N.R.E.M stage 3 sleep allows you to feel refreshed the next day. During N.R.E.M stage 3 sleep:

• Your muscles are completely relaxed,
• Your blood pressure drops, and breathing slows, and You progress into your deepest sleep.

During this deep sleep stage, your body starts its physical repairs. Meanwhile, your brain consolidates declarative memories such as personal experiences and other things you have learned.

Stage 4

R.E.M sleep begins approximately 90 minutes after falling asleep. At this time:

• Your brain lights up with activity,
• Your body is relaxed and immobilized,
• Your breathing is faster and irregular,
• Your eyes move rapidly, and
• You start to dream.

During R.E.M sleep, your brain's activity most closely resembles its activity during waking hours. However, your body is temporarily paralyzed. This is a good thing, as it prevents you from acting out your dreams.

Like stage 3, memory consolidation also happens during R.E.M sleep. However, it is thought that R.E.M sleep is when emotions and emotional memories are processed and stored. Your brain also uses this time to cement information into memory, making it an important stage for learning.