Also Known As: Vivid dreams, nightmares
Dreams are successions of images, ideas, emotions, and sensations that occur involuntarily in the mind during certain stages ofsleep. The content and purpose of dreams are not definitively understood, though they have been a topic of scientific speculation and a subject of philosophical and religious interest throughout recorded history. The scientific study of dreams is called oneirology. Scientists believe that birds, reptiles, and other mammals also dream.
Dreams mainly occur in the rapid-eye movement (REM) stage of sleep—when brain activity is high and resembles that of being awake. REM sleep is revealed by continuous movements of the eyes during sleep. At times, dreams may occur during otherstages of sleep. However, these dreams tend to be much less vivid or memorable.
Dreams can last for a few seconds, or as long as 20 minutes. People are more likely to remember the dream if they are awakened during the REM phase. The average person has three to five dreams per night, but some may have up to seven dreams in one night. The dreams tend to last longer as the night progresses. During a full eight-hour night sleep, most dreams occur in the typical two hours of REM.
In modern times, dreams have been seen as a connection to the unconscious. They range from normal and ordinary to overlysurreal and bizarre. Dreams can have varying natures, such as frightening, exciting, magical, melancholic, adventurous, or sexual. The events in dreams are generally outside the control of the dreamer, with the exception of lucid dreaming, where the dreamer is self-aware. Dreams can at times make a creative thought occur to the person or give a sense of inspiration.
Opinions about the meaning of dreams have varied and shifted through time and culture. Dream interpretations date back to 5000–4000 BC. The earliest recorded dreams were acquired from materials dating back approximately 5,000 years, in Mesopotamia, where they were documented on clay tablets. In the Greek and Roman periods, the people believed that dreams were direct messages from the gods or from the dead, and that they predicted the future. Some cultures practiced dream incubation with the intention of cultivating dreams that areprophetic.
Sigmund Freud, who developed the discipline of psychoanalysis, wrote extensively about dream theories and interpretations. He explained dreams as manifestations of our deepest desires and anxieties, often relating to repressed childhood memories or obsessions. In The Interpretation of Dreams, Freud developed a psychological technique to interpret dreams and devised a series of guidelines to understand the symbols and motifs that appear in our dreams.