■ What goes on inside your brain when you’re dreaming? Well, as it happens, no one seems to know exactly. Not the mystics with the crystal balls, not the dream interpreters, and not even, as you might suspect, scientists. While several theories are floating about in both the scientific and non-scientific worlds about what dreams are, what causes them, and how the brain comes up with them, there’s no conclusive evidence about any of it.
__The scientific theories come down to the following: Your dreams are expressing your repressed childhood longings; they’re sorting through the garbage of your day-to-day existence; or, finally—the one scientists are most recently exploring—they’re just random brain impulses and have very little significance whatsoever to your life choices as a whole.
__Sigmund Freud was among the first to come up with dream theory, and, predictably, he suspected that dreams were based on desires that were either socially unacceptable or repressed for other reasons. For the most part, he believed that dreams were largely based in sexual desires and symbolism. Carl Jung, who studied under Freud, took the idea of psychological expression but went a bit further with it, disagreeing with Freud on the repressed nature of desires being expressed through dreams. He suggested instead the now popular view that dreams allow us to think through our problems and issues of the day, albeit subconsciously.
__Then, in 1973, another theory started gaining ground. Harvard psychiatrists Drs. Allan Hobson and Robert McCarley carried out research that basically came down to this: Dreams are made of random electrical brain impulses. The brain is built up of billions of nerve cells, or neurons, and electrical impulses are sent from neuron to neuron, which enables “messages” to be transmitted in the brain. Every action we take—speaking, for instance—requires messages to go to and from the brain to the body, and these electrical impulses carry those messages through.
__The Harvard psychiatrists believed that dreams were made of these random transmission impulses to and from the brain. Their theory, called the activation-synthesis hypothesis, was that the brain wants to make sense of what it has seen and experienced throughout the day, and so when you’re sleeping, it digs into that vat of information and starts the processing. According to Hobson and McCarley, the images are just leftovers of brain processing and our waking mind trying to process what it’s seen. They dismissed the idea that there are hidden meanings in dreams; Hobson called it “the mystique of fortune cookie dream interpretation.”
__Their theories met with much opposition. Then, and even now, popular science has always had the opinion that our dream states and waking states were connected through our dreams, and this research went against the popular grain of thinking at the time.
__This theory, however, is supported by other research. In a study of 1,000 people, researchers at Carnegie Mellon University and Harvard found that people attach more significance to dreams that feature familiar people or situations. More so, if the dream was about someone they liked, they attached more positive bias to it, and vice versa if it was about someone they disliked.
__Other research suggests that very few dreams are actually about people or places the dreamer knows or has encountered. Most—that is, 80%—are actually random events or people the dreamer doesn’t know.
What Happens While You’re Dreaming?
So what goes on in the brain when you’re asleep?