What are Dreams?

I caught a super fascinating documentary on PBS last night called What are Dreams?. It focused more on the reasons why we dream, rather than what our dreams mean (although there was some of that too). I've long known that the brain is sorting things out while we sleep (which gives a lot of truth to the old saying, "sleep on it."). I remember staying up late cramming for some big biology exam when I was in college and oftentimes I would hit a wall. I'd read some passage in a textbook over and over, but couldn't really understand it. But I found that if I got some sleep, the next day I'd pick up the concept very quickly. As the program shows, scientists now know that Rapid Eye Movement (REM) sleep enhances creative problem-solving.

The documentary also made me realize that in order for us to understand the brain (which is basically still a black box to us), we must understand dreams. Given that we spend one-third of our lives sleeping, this makes sense. Here's the program description, in case you are interested (check airing dates here):

Delving deep into the thoughts and brains of a variety of dreamers, scientists are asking important questions about the purpose of this mysterious realm we escape to at night. Do dreams allow us to get a good night's sleep? Do they improve memory? Do they allow us to be more creative? Can they solve our problems or even help us survive the hazards of everyday life?

NOVA follows a number of scientists, including Matthew Wilson of MIT, who is literally "eavesdropping" on the dreams of rats, and other investigators who are systematically analyzing the content of thousands of human dreams. From people who violently act out their dreams to those who can't stop their nightmares, from sleepwalking cats to the rare instances of individuals who don't seem to ever dream, each fascinating case study contains a vital clue to the age-old question: What Are Dreams?