What Are Dreams Anyway?
Harry Potter roams my daughter's dreams. So does Hermione Granger and, to keep things interesting, Harry's adversary, Draco Malfoy. All this is intentional, I learned recently. Libby, who is 12 and has devoured every one of J.K. Rowling's books, joins these characters every night after telling herself to dream about them. "I put myself in the movie," she says. On other nights, for variety, she practices martial arts with characters from Kung Fu Panda.
My wife, Diana, takes wing in her dreams. Sometimes, she tells me, she simply elevates from a standing start. "I just spread my arms out and fly," she says. It's always a sunny day, warm, and the dream is usually set near her childhood home in a small Indiana town. Occasionally there's drama -- she'll lose control and regain her flying ability right before she hits the ground. But most of the time she's just soaring.
As for my own dreams, the other night I was running across a town square. A guy was shooting at me. I ducked for cover into a blue sedan only to find the shooter inside the car. My heart skipped two beats -- but then the villain suddenly morphed into a harmless old man.
Other dreams I have are much more fun. There was the one a while back in which I ended up with -- ahem -- sexy blonde twins. More about those kinds of dreams later.
So what are dreams anyway? The ancient Greeks said they were messages from the gods. Sigmund Freud called them a "royal road" to the unconscious mind, full of threatening sexual and aggressive urges that we normally keep in check. In the 1970s scientists figured out that dreams are regulated by a chemical that comes from our primitive brainstem and kicks off the rapid-eye-movement, or REM, phase of sleep. Some scientists concluded, then, that our dreams were simply random stories concocted by the brain. Freudians were not happy with this view. Three decades later scientists are still arguing, still studying -- and now beginning to bring the dreaming mind into sharper focus, showing us why we should pay attention to what goes on each night.
Here's how the road to dreamland works: As you doze off, your brain waves slow, your muscles relax, and your heart rate and blood pressure fall. About an hour and a half later your brain stem sends its chemical signal and your brain waves speed up, your heart beats faster, your temperature rises, and REM sleep kicks in. The sleep cycle repeats four to five times a night, with progressively longer periods of REM sleep each time. That's why dreams tend to pile up as morning approaches -- or diminish when you're sleep-deprived.
When you're asleep, two key functions of the brain stay off-line. The area that controls movement is shut off, paralyzing you from the base of the brain down, which is why your legs and arms don't pump when you're fleeing a dream monster. (Malfunctions in this mechanism may lead to sleepwalking in the stage of sleep before REM but don't explain why sleeping dogs' legs sometimes move as if they're running in their dreams.) A brain region near your forehead that usually lets you distinguish reality from, say, a movie, is also shut down, says Ross Levin, PhD, a sleep specialist in private practice in New York City. That's why you don't think it's strange when you see elephants in your dream living room or George Clooney seems about to kiss you.
On the other hand, the limbic system, which controls your emotions, is working overtime. It pulls fragments of memories -- the snooty comment yesterday from the woman in the next cubicle, your friend from eighth grade who didn't invite you to her party -- and creates a story out of them. So all this helps explain why dreams are emotionally intense and surrealistic yet feel utterly real.