Before dreams begin, a person goes through a sleep cycle. Eugene Aserinsky and Nathaniel Kleitman of the University of Chicago discovered the sleep cycle in 1953. (HowS) This discovery was made using electrodes. The electrodes were attached to the test subjects in seven locations. Three electrodes recorded brain activity and brain waves, and two more recorded eye movement. An electrode was placed on the neck to record the vocal tone coming from the neck or any other sound coming from the subjects. A final electrode was placed on the chest to record heart rate. The result of this study was that humans have five sleep stages. (Book) A different amount of time is spent in each phase, but the night is not divided equally between the five phases. The first stage of sleep is a very light sleep from which it is easy to wake up. Normally only 4-5% of the night is spent in this phase. The second phase is when your body temperature drops and your heart rate slows and you begin to enter a deeper sleep. In the second phase, 45-55% of the night is spent. Four to six percent of the night is spent transitioning into deep sleep, known as stage three. Deep sleep occurs during stage four and approximately 12-15% is spent in deep sleep. Sleepwalking and bedwetting usually occur at this stage because it is when the muscles begin to relax. The final stage of sleep is called the rapid eye movement stage or REM sleep. Dreams occur primarily during REM sleep, and typically 20-25% of the night is spent in this phase. During the night, humans do not go through the five phases just once. According to sleep studies, a typical sleep cycle goes from stage one to stage four, back to stages two and three, moving on to s...... middle of paper ...... showing the emotions you repress during the day in their dreams. If someone thinks a lot about a certain person or problem during the day, it is possible that it will appear in their dreams that night. Additionally, spending a lot of time with a person can cause them to find themselves in more dreams. Recurring dreams can be caused by anxiety about certain real-life situations that are not being addressed or have not yet been resolved. Traumatic experiences and memories often appear in dreams and can influence their content. Trauma can also be a factor in recurring dreams. If a crucial issue needs to be recognized and addressed, the subconscious may work very hard to make sure this happens. The subconscious creates a dream within a dream to prevent you from waking up. Create a safe place to express emotions and resolve problems without interruption.