Throughout history--from ancient shamans to the Bible to Freud--men and women have been fascinated by dreams and have pondered their meaning. Current research indicates that dreaming has a real, practical function but also that it can spark our imaginations in unexpected ways. Best of all, one doesn't have to be especially "adept" at dreaming: The power of dreams is accessible to everyone.

New studies confirm that all of us have dreams--even those who never recall them--every night for 90 minutes to three hours, in four or five cycles. MRI images and PET scans show that specific areas of the brain are triggered at regular intervals, giving us dream imagery.

Until recently, many scientists dismissed the idea that there was rich meaning in dreams, believing instead that dreams were initiated by random firings of the brainstem during REM (rapid eye movement) sleep. But evidence has been accumulating that dreams also can originate during other phases of sleep, when the higher visual and emotional centers of the brain are activated. This suggests that our dreams are not strange results of meaningless biological processes. Rather, they are produced by the part of the brain tied to motivation, goals and desires.

Dreams may even be related to survival itself. Antti Revonsuo, a psychology professor in Finland, theorizes that dreaming is central to human evolution. "A dream's biological function is to simulate threatening events and to rehearse threat perception and threat avoidance," he explains. That is, our dreams can warn us of challenges ahead and give us a chance to rehearse efficient responses--including getting out of the way. I once dreamed of a car accident on a hill east of Troy, N.Y. Several weeks later, driving on the same hill, I found my view of a curve in the road obscured by a delivery truck ahead. I remembered my dream and slowed almost to a stop--avoiding a head-on collision with an 18-wheeler.

Dreams also can alert us to dangers that are internal. They may tell us what is going on inside our bodies and what we need to do to stay healthy. Mary Agnes Twomey, a registered nurse in Baltimore, dreamed she'd traveled inside her body and found it was like a boiler room in danger of blowing up. Upon waking, she made a doctor's appointment and learned she had an ulcer that needed treatment. Other people have reported dreams that alerted them to illnesses ranging from breast cancer to heart disease.

Whether or not you believe that dreams serve as warnings, studies suggest that they play a critical role in learning and memory.

"Dreams allow us to play and experiment with new conditions or find novel solutions," says Richard C. Wilkerson, operations director of the International Association for the Study of Dreams. "They allow us to explore unusual areas of life and practice new behaviors."

One fertile source of creativity is the ability to make new and unexpected connections--something we do all the time when we dream. In dreams, "connections are made more easily than in waking, more broadly and loosely," says Dr. Ernest Hartmann, a professor of psychiatry at Tufts University who has written widely on sleep and dreaming. But he adds, "The connections are not random. They are guided by the emotional concerns of the dreamer." In dreams you may gain new insights about personal relationships or develop exciting new ideas.

Many artists have experienced this phenomenon: Paul McCartney awoke with the music for the Beatles' hit "Yesterday" in his mind. Architect Frank Gehry has said that his building designs were influenced by his dreams.

"The waking mind is thinking inside the box; the dreaming mind is thinking outside the box," explains David Kahn, a professor at Harvard Medical School.

This may be why solutions to nagging problems often come to us in dreams. Robyn Johnson, a consultant for nonprofit organizations in Washington state, needed to produce a fund-raiser for a city park. She dreamed that Annie Oakley rode into the park on her horse, urging her to produce a children's storybook to be given to every guest. She followed Oakley's advice, to great success.

Not least, dreams can help us deal with emotional hurdles. Marlene Cantor at the May Institute in Massachusetts has discovered recurring themes in the dreams of middle-aged women. One woman dreamed night after night of going to a house that was falling into disrepair. It began to crumble around her, and one night she saw the roof falling in. In another dream, she saw a beautiful young girl run out of the house and into the path of a speeding car. She wept as the girl died in her arms. In sharing these dreams, the woman reflected that the first symbolic dreamscape might express her fears about her aging body. And perhaps in weeping over the young girl's death, she was mourning the death of her younger self.

"Most of these women had never really talked to anyone--not family, not even therapists--about what they were feeling," Cantor recalls. "Telling their dreams brought them a tremendous sense of relief, of coming out of silence and solitude."

Whether we share our dreams or reflect on them privately, we'd all do well to wake up to their power. Amid the stress and clutter of everyday life, our dreams can help us discover what's most important.

How To Use Your Dreams

- Record your dreams. Instead of rushing into the business of the day, schedule 15 minutes each morning to think about your dreams and note them in a journal. If you can't recall a dream, jot down your first thoughts and feelings upon waking. This sends a message to your dreaming self: "I'm ready to listen."

- Find a dream friend--someone who will provide helpful, non-intrusive feedback. When you listen to a friend's dream, ask how he or she felt upon waking (angry? calm? excited?) and what the dream might be saying about the future. When you offer an interpretation, say: "If it were my dream..." That way, you give an opinion without taking away the dreamer's power.

- Take action. If you dream that your office is sinking like the Titanic, it may be time to revamp your résumé. If you dream yourself in an ideal home and are disappointed upon waking, think of practical steps you can take to bring reality closer to your dreams.