Dream On ...

Long before Frankenstein's monster appeared in the famed 1931 film, he visited the dreams of author Mary Shelley. Her classic work of horror has haunted our sleep ever since, proof of the creative power of dreams is everywhere: In the surreal paintings of Salvador Dali and Renee Magritte, even in the bittersweet melody of Paul McCartney's "Yesterday," which he says came to him in a dream.

Whether you are prone to such flights of fancy or, perhaps, towards darker visions, if you are a human being, you dream.

"Dreaming is as natural as breathing," Kelly Bulkeley, who studies the role of dreams in culture and religion, told The Early Show medical correspondent Dr. Emily Senay. "It's one of those sort of universal features of being human."

"The dreaming imagination is just infinitely creative. I mean, in dreams, we can be any place, with anyone, doing anything. We benefit by being creative, adaptive, flexibly-thinking beings. And I think dreams help keep those processes in good working order."

The notion that they help us maintain mental agility is the latest in a long line of theories about why we dream.

In religion, they've traditionally been viewed as prophecies of the future; psychiatry has seen them as windows into the subconscious; but much of today's dream research focuses mainly - to borrow McCartney's lyric - on yesterday…

Harvard researcher Erin Wamsley believes dreams play a vital role in the formation of memories.

I let her wire me up as part of an experiment to see if I can improve my performance making my way through a video maze by sleeping - and perhaps dreaming about it.

"There might be some very practical applications of studying dreaming if it turns out that dreams are a way to view how memory processing occurs during sleep," Wamsley said. "Looking at dreams could help us to understand how we take a new experience and integrate that with our past experiences using it to guide future action."

With Wamsley keeping an eye on my brainwaves, I'm off to dreamland…

While Sigmund Freud believed dreams were a form of wish fulfillment - what he called "the royal road to the unconscious" - starting in the 1970s, many scientists began to move away from attaching any importance to what they saw as the random workings of the mind.

Random or not, millions of people still want to believe that there is something more to their dreams, and there's a growing consensus among researchers that the key to making sense of dreams is, well, a healthy dose of common sense.

For the past five decades, G. William Domhoff, of the University of California, Santa Cruz, has been assembling what he calls the "Dreambank," a database of some 17,000 dream journal entries, broken-down into simple categories like aggression, sexuality and emotion.

"Dreams are by and large a realistic simulation of our every day lives," Domhoff said. "Often with a little quirk thrown in. It's not quite the right furniture in the house. Uncle Joe has on a little different shirt than he usually does. Somebody acts a little unusual. But by and large, these dreams are acting out our everyday kinds of concerns."

According to the Dreambank, fantasies of flying may be a mainstay of movies like "The Big Lebowski," 'but it turns out that anxiety - as portrayed in Woody Allen's "Stardust Memories" - is a far more frequent sentiment in our slumber.

"You're more likely to be attacked by somebody, whether verbally by saying, 'I don't like you,' or rejecting you, or even chasing you, than to have a friendly interaction, where somebody says, 'Can I help you?' Or they give you a gift. So dreams are on balance more negative than they are positive. And as one of my students once put it, dreams are worse-case scenarios."

Take the waitress who dreams of breaking dishes. It rarely happens in waking life, but it's a regular occurrence in her sleep.

So, for most of us, the mingling of memory and imagination is a benign way of dealing with daily worries.

But for the estimated four to eight percent of adults who suffer from regular nightmares, bad dreams can be a serious problem.

"It seemed like the nightmares became a part of me, a part of who I was," said Linda (who asked her last name not be used). For her, nightmares were a nightly routine since age five. She blamed them on the domestic violence she'd seen in her family.

It wasn't until she took a job in (of all places) a sleep clinic, that Linda first sought treatment.

"She was at her wit's end about the fact that she had had these sleep problems, these nightmares, for so long," said Dr. Barry Krakow, who directs the Sleep and Human Health Institute in Albuquerque, N.M. "And like so many people, never imagined there was something that you could do about it."

Krakow, author of "Sound Sleep, Sound Mind" (www.soundsleepsoundmind.com), believes that while mental trauma like Linda's can be a major cause of nightmares, physical problems can contribute, too.

"When people walk in the door and say, 'I've got a nightmare problem,' their risk, in my clinical experience, and research, is that they have greater than a 70 or 80 percent chance that they also have a breathing disorder," Krakow said.

In these cases, Krakow often prescribes breathing masks which help patients sleep through the night.

"When you have sleep apnea, or sleep breathing problems, you're sleep is horribly fragmented. You're constantly going between awake and asleep all the time. And that in itself is disquieting and disruptive to you. I believe that does stimulate bad dreams, I believe that's exactly what happens."

If nightmares persist, Krakow recommends a visualization technique to practice before bedtime.

"You need to take that dream and change it any way you want," Krakow said. "Then, once it's changed, you need to close your eyes and picture in your mind the changed version. And just do that every day for a few minutes each day. That's the treatment. That's it."

For Linda, it's still an ongoing process.

"If I were to have a bad dream, I learned how to basically, recreate that dream and make it positive," she said. "So, say I had a dream about a dog chasing me. I could turn into dogs running in the park, a sunny afternoon with my family, and I wouldn't have that bad dream anymore."

Back in the Harvard sleep lab, I'm not having bad dreams - or any dreams at all. I just couldn't doze off!

Although I didn't contribute much to Erin Wamsley's research, the lab is already getting results:

They've found two-thirds of game players reported having dreams about it - suggesting the new memories took hold.

Perhaps there really is something to the old advice to "sleep on it."

All mammals experience rapid eye movement (R.E.M.) sleep, which is when most dreaming occurs. (Source: Science.