Before the 1950s scientists believed that when a person drifted off to sleep, their body would shut down and enter a passive state that would allow them to recover from the previous day. Sleep is actually much more complicated. Your brain goes through different stages and patterns of activity. It is a routine cycle and includes NREM sleep (Non-REM sleep) and REM (Rapid Eye Movement) cycles.
Stage one: Happens very quickly after you’ve fallen asleep. The brain produces alpha and theta waves. It is a brief and light period (lasting only 7 minutes) and you can be roused easily.
Stage two: Also a light stage, the brain produces a sudden increase in brain wave frequencies and then slows down. (if you want a power nap it's best to wake up after this stage)
Stages three: Beginning of deep sleep. The brain begins producing slower delta waves. No eye movement or muscle activity. Harder for you to wake up, you become less responsive to external stimulus.
Stage four: The brain produces more delta waves. Fall into a deeper sleep. This is a restorative stage where the body repairs muscles and tissues and stimulates growth and development. Boosts the immune system and builds up energy for the next day. It is very hard for you to wake up.
REM sleep usually occurs 90 minutes after you fall asleep. Each REM cycle can last an hour. During this stage your brain becomes more active, this is when most dreaming occurs. Your eyes jerk quickly in different directions, your heart rate and blood pressure increase and breathing becomes irregular.
REM sleep plays an important role in learning and memory function. It is the stage where your brain consolidates and processes information so that it can be stored in your long term memory.
Studies show that the quantity and quality of sleep have a great impact on learning and memory. Learning and memory are described in three parts. Acquisition is the introduction of new information into the brain, consolidation is the process by which memory becomes stable, and recall is the ability to access the stored information. Acquisition and Recall happen while you are awake but memory consolidation happens while you are asleep.
REM sleep and SWS (slow-wave-sleep - stages three and four) are important for fact-based information to be consolidated and visual learning. REM sleep is also important for the consolidation of instruction-based information. Motor learning depends on the amount of lighter stages of sleep.
When a person is sleep deprived they will not be able to focus their attention or properly retrieve learned information. You lose your ability to make rational decisions and your judgment becomes impaired. Lapses in focus can even result in accidents and injury. Studies involving memory tests show that after a single night of sleep, or even a nap, people perform better, whether on a test, in the office, or on the athletic field.
Comments