[9급 국가직 영어 2007년 19번]

Humans have always been fascinated by dreams. The vivid dreams people remember and talk about are REM dreams ― the type that occurs almost continuously during periods of rapid eye movement (REM) during sleep. But people also have NREM dreams ― dreams that occur during periods without rapid eye movement ― although they are typically less frequent and less memorable than REM dreams. REM dreams have a story-like or dream-like quality and are more visual, vivid, and emotional than NREM dreams. Interestingly, blind people who lose their sight before age five usually do not have visual dreams, but they have vivid dreams involving the other senses. A popular belief about dreams is that an entire dream takes place in an instant, but in fact, it is not true. Sleep researchers have discovered that it takes about as long to dream a dream as it would to experience the same thing in real life.