How would you like to step into the weird and often messy world of other people’s dreams It’s not a problem for Special Agent Dom Cobb (Leonardo DiCaprio). The industrial spy steals secrets when his victims are at their most vulnerable, when they are asleep and dreaming. He has an even rarer ability: He can plant an idea in someone’s sleeping mind, and watch it grow and take root in reality. This ability is called inception.
A dream is a series of visual images and audio sounds formed by nerve signals in the brain during sleep. In the 1950s, researchers discovered a cycle that occurs around every 90 to 120 minutes during sleep: rapid eye movement, or REM. During this period you’re fast asleep, yet your brain is nearly as active as during the day, that’s when most dreams occur.
In 1900, Sigmund Freud published his landmark study, The Interpretation of Dreams. For Freud, dreams are a complicated system of unconscious desire and conflict that are always connected to early childhood. They are expressed through very specific symbols, most of which are ual. An apple or a peach symbolizes a woman’s breast, for example.
Many contemporary scientists believe that dreams can have definite meanings and express repressed inner emotions, such as fear and anxiety. So if you dream of being chased by a giant spider, for example, it could reflect that you feel trapped by some current situation or relationship you want desperately to escape but are afraid to confront.
According to Freud, a dream springs from an unconscious Wish or desire during sleep. Some today have a different view: We dream simply because during sleep the forebrain fires random nerve Signals, as a way of "resetting" a complex system of brain chemicals. It is as if the sleeping brain is quickly and randomly cleaning house for better use during the day.
We typically spend more than two hours each night dreaming. Parts of the brain are nearly as active during sleep as when you’re awake. These parts interact to form dreams. Dreams almost always occur during REM sleep.
The pons--a small band of nerves in the brain stem--fires nerve signals that cause REM sleep, as well as visual images-and audio sounds of dreams. The pons also sends signals that shut off neurons in the spinal cord, causing temporary paralysis of the limb muscles,
Your daytime experiences are stored as memories in the hippocampus (大脑海成区). During REM sleep, the hippocampus may help replay the memories in a kind of "twisted" dream form. Some researchers think that dreams help translate daytime experiences into long-term memory; dreams may also help you make mental connections that build up the skills you learn when awake.
Some scientists believe dreams are the cortex (脑皮层)’s attempt to find meaning in the random signals that it receives during REM sleep. The cortex is the part of the brain that interprets and organizes information from the environment during consciousness. It may be that, given random signals from the pons during REM sleep, the cortex tries to interpret these signals as well, creating a "story" out of fragmented brain activity.
From the passage we can NOT infer that ______.