TIFT #95: My Favorite Brain Network

It’s the source of our creativity, intuition, hunches, and all the fuzzy stuff that enriches our lives. Neurologists just call it the DMN, default mode network. From a brain standpoint that makes sense. It is the huge network of interconnected neurons that operate when the brain is idle, not focused on anything in particular. For neurologists it started out as a curiosity. Even when there was no apparent mental activity, brain cells were still consuming energy. They had to be doing something, but it wasn’t clear what. The brain consumes a lot of calories of energy and evolution is stingy about expending any of that, so the activity must be important. However, with science largely focused on conscious thought, it wasn't apparent what. So they called it the default mode network. 

Surprise:

As it turns out, this ugly duckling of brain networks is a swan! Once we appreciate that our brains are operating, mostly outside of consciousness, like those of our mammalian ancestors, then we begin to get curious about activity going on behind the scenes during quiet time. Those times are when the mind goes to work to bring order to what it knows and to find answers to questions it finds puzzling.

When you have lost something and no amount of effort trying to remember seems to bring it back to mind. Your best bet is to stop trying and let your DMN work in the background. And when you can’t solve a problem, “sleep on it.” Your DMN will be working all night on your behalf and will serve up the answer in the morning, most likely while you are in the shower and don’t expect it.

When was the last time you had a great new idea? It was probably when your DMN put two things together in a fresh way. That’s what creativity is, and it’s the DMN’s specialty. It works by associative logic where chunks of information, “things,” are related, but without worrying about the exact nature of the relationship. 

And did you notice that those same loose associations are the heart of humor? What makes jokes funny is that they put things together in a way that is suddenly obvious but you would never have thought of it. I asked ChatGPT for an example and she came up with one, presumably gathered from someone’s DMN:  “Why did the bicycle fall over? Because it was two-tired!” The association is just that, the connection between tire and tired is not logical but it’s exactly the kind that is native to the inner mind’s associative logic.

The DMN also seems especially facile at relating things as opposites. I suspect that this is an important, built-in property, perhaps related to the fact that nerve cells influence one another in two ways, facilitating firing or inhibiting it. Once again, when opposites pop into consciousness, the exact nature of the opposition is undefined. That’s quite different from conscious logic but extremely useful. By combining associations that are similar with ones that are opposite, the DMN is able to arrive instantly at logical conclusions like: “The enemy of your friend must be your enemy.”

How I use my DMN

I get the most from my DMN by programming it the night before and harvesting in the morning. Before sleeping, I immerse myself in a problem that has been nagging. That’s all it takes to set the DMN in motion and I go peacefully to sleep. Reliably, the answer wafts into consciousness at some unexpected point in the morning.

One of the most remarkable examples for me is the mind’s skill as an editor. When I write a post like this I put aside the first draft. Sometime later, often in the morning, my DMN will tell me there is something I missed or that needs to be said differently because the original was awkward. I’m amazed. I had no idea my mind was so aware of the detailed contents of my draft. Yes, I do remember being slightly uncomfortable about a certain phrase, but the DMN was right there on the job, realizing that it had to be changed and what to say instead.

The DMN Advantage

Some people are more creative. That’s an advantage, but it is also part of the neurodiversity that is typical of Attention Deficit Disorder. Why do so many artists have trouble with drugs and chaotic lives? What brain research shows is that normal people (ADD folks call them “linear”) switch off their DMN when they are focused on a task or subject. People with ADD tend to leave theirs on and have more trouble switching to their TPN, “Task Positive Network.” You might think that difficulty directing attention to a task is a terrible handicap, and in some ways it is. But “dreamers,” who have this trouble are more likely to come up with innovation and fresh ideas. Yes, they do tend to focus on the immediate and may not pay enough attention to future consequences, which can lead to some chaos. On the other hand, they are lively and fun, that is if you can cope with the randomness. One more saving characteristic of many ADD people is that they can “hyper-focus.” When they have plenty of natural adrenaline, as in sports, performing arts, and face-to-face human interaction, they become totally focused, often more deeply than "normals." That’s when they really perform. It is also why ADD kids do well in the hard subjects and poorly in the boring ones.

Can you cultivate your DMN?

I don’t know the science about further enhancement of abilities that are already present, but what is clear is that there are ways to make the best use of what you have. First, practice articulating the questions and problems you are facing. Your TPN (Task Positive Network) will do a good job of analyzing things to put into words exactly what you haven’t been able to solve. A well-stated question is candy to your DMN. We all know that it is profoundly human to like stories. What is not as well recognized is that a question is the same as the beginning of a story. The mind immediately wants an answer. “OK, but what happens in the end?” What Jaak Panksepp calls the “SEEKING SYSTEM” goes to work motivating the DMN to find the answer and bring the story to a satisfying end.

Having set up your DMN to go work on the problem you have posed, what remains is to harvest the answer. All that takes is the increasingly rare practice of doing nothing. Make sure you have idle time, especially in the morning. Do the dishes by hand, linger in the shower, drive to work with the radio off. Harvesting takes place when your TPN is turned off. That is when your DMN will reward you with answers popping into consciousness when you least expect them.

Jeffery Smith MD

Photo: Te Nguyen, Unsplash