Stages of Sleep essays

Stages of Sleep essays Psychology has described sleep as periodic, natural, reversible loss of consciousness. Over a period of time our bodies fluctuate and so does our mind. These physiological fluctuations are called biological rhythms. These rhythms are controlled by our biological clock, or circadian rhythm. Around every 90-100 minutes we go through a series of sleep stages called cycles. When you slip into sleep you do not know you are sleeping until you wake up. Sleeping is marked by slow breathing and irregular brain waves. We slip into Stage 1 of sleep, which lasts up to 5 minutes and may produce images. Sometimes these images resemble hallucinations-sensory experiences which occur with out sensory stimulus. You may feel as though you are falling or floating. These hypnologic sensations later may be incorporated into memories. As you relax deeper you begin about 20 minutes of Stage 2 sleep, which is marked by periodic appearances of sleep spindles-which are bursts of fast, rhythmic brain wave activity. You can still be awakened with out much difficulty during Stage 2 of sleep, but you are definitely asleep. Sleep talking may occur during this and other sleep stages. After Stage 2 you move for a few moments into a transitional Stage 3 sleep, then into a deep sleep or Stage 4. During Stage 3 and more so during Stage 4 your brain releases large slow delta waves. Together these stages are called slow-wave sleep. Delta waves last for around 30 minutes, while which it becomes harder to wake you up. Even while you are in deep sleep your brain processes certain stimuli. For example you can move about your bed with out falling out. About an hour after you first fall asleep instead of continuing in deep sleep you rise back up from your initial dive. You return to Stage 3 and Stage 2 (where about half of your night is spent) then you enter REM sleep. REM sleep is a recurring stage of sleep during which d ...