I dreamed about you last night

Is it just me, or is everyone fascinated by neurobiology, or the study of the brain? Thanks to magnetic imaging and other technologies, scientists can monitor living brains in real time. The result is that old questions are getting fresh answers, and one of the oldest has to do with dreams.

Why do we dream? Is there any meaning to the show between our ears? Do animals dream like we do? All of these questions have eluded evidential research for years—until now.

Radio Lab, one of my favorite podcasts, recently did a show on sleep, and a Harvard professor named Robert Stickgold featured into the last third of it. Dr. Stickgold walks patients through certain activities while awake—most notably the video game Tetris—and then wakes them up at various intervals in a sleep lab to get the skinny on how their dreams are going.

Turns out, there are two activities going on while you are asleep. The first activity is that the brain bathes all the synapses formed during the previous day’s experiences. This weakens them, so that only the most prominent connections stay in the memory. Think of every experience you have like noise. Sleep turns the volume down, so that only the loudest noises remain. I don’t remember eating breakfast last week, for example, but I do remember the plot to Thomas Hardy’s Jude the Obscure, which I finished at the same time. The second activity is problem solving. During the day, the brain marks any activities which peaked your emotions, good or bad, with a tag that says something like, “Could be a problem. Work it out later.” While you are asleep, it gathers up all the tagged material and starts figuring it all out. At first it is very literal. You see the social gaffe or the details of the financial decision. But then it begins to free associate, plugging in other stored memories that sort of match the initial situation.

Both activities mean that your brain is not a static entity. Every experience that you have during the day creates new synaptic connections, and some of these remain over the course of time. They also explain why learning occurs so much easier in the mornings: you have less noise, less synaptic clutter, in the brain, all of it having been cleaned out while you were sleeping the night before.

Now where am I going with this? Well, my wife and I have very different dream lives, and I am wondering whether this new information might actually help me understand her and myself a little better. I almost never remember my dreams. I hurtle into sleep, but once there I drift around aimlessly. When I wake up and stumble into the bathroom for the morning pee, I hardly ever think about the dream life I left behind. My wife, on the other hand, has terrifically vivid dreams, full of complicated situations and emotions. She enjoys and even cultivates her dreams like a dedicated hobbyist, and enjoys regaling a listener with them upon waking. Her worlds are populated with the same people, primarily her mom and people from high school. I and the kids make an appearance on occasion and, just recently, some church friends have shown up. Her dream life is very important to her. My dream life doesn’t get a nod.

Now based on this science, can we learn anything from this? And how do we know what is an important brain-tag and what is just detritus? Might someone say that the inconsequence of my dream life means I’m not emotionally engaged in the world? Might someone ask whether my wife is still trying to work out some issues left over from high school? (Who doesn’t have those? And she had a fantastic high school experience; mine was the reject.) What does this mean for marriages? If the daily experiences of man and wife are very different, doesn’t that mean that, over time, the synaptic outline of their brains becomes radically different? Is there a neurological reason why husbands should take their wives out on occasion: to build a few synapses in common? Could a dream diary help you understand what your brain thinks are the most important issues in your life? What if someone you know never shows up in your dreams? Is your brain trying to say they are a wet fish, though good manners calls for reciprocal hospitality ad infinitum? And instead of thinking it is creepy if someone says, “I dreamed about you last night,” it may just be that their brain finally included you in the contacts list.