The default mode network
I come from a family of chemists. My mother and father were chemists as were my grandfather and great-grandfather. I’m not a scientist myself, but I was brought up with that worldview and I still see things that way.
So there I was, sitting on the floor an hour or so after drinking the second serving of the Daime tea, looking down at the wreckage of my ego and marveling at how quickly it all fell apart. When rational thought eventually returned, my first question was:
“Did the concentration of the chemical in my bloodstream cross a threshold level?”
That explanation made sense because, whatever happened, it felt like somebody flipped a switch. One moment I was my familiar, cranky self, and then… BLAM! The walls came tumbling down and I was suspended in an empty space, surprised by total peace and freedom.
The only similar experience I can recall is from the early days of my meditation practice. Indeed, there are research studies that show similarities in the way that meditation and psychedelic drugs act on the nervous system. Both reduce activity in the default mode network, the parts of the brain that kick into gear when we’re not focused on external tasks.
I’m way out of my depth with this issue, and experts disagree, but it appears that the default mode network is the engine that creates our inner life, our sense of identity in relation to other humans and the world around us.
The default network may generate models of reality and drive the inner monologue. It may also create illusions and habits and other traps that keep us locked in our egos. Whatever it does, for good or ill, requires a ton of mental processing. Psychedelics and meditation pull the plug.
In my case, the shutdown was a big relief. It felt like a huge burden falling off my shoulders. All the accumulated noise of a lifetime fell away, leaving a sense of clarity and liberation. It happened in a flash, just like you’d expect if a chemical in your bloodstream reached a threshold level and shut down one of the major systems in your brain.
Of course, it also felt like a gift of God’s loving grace. Perhaps those are just two ways of describing the same experience.
Posted in: Reason and Magic
Leave a Comment (2) ↓
I would expect that when “the default mode network” is deactivated, you can’t really concentrate (nor want to), except perhaps on sensory input. But I suppose you didn’t do experiments along those lines!
Random thought of the day: Since very high level and abstract tasks use the frontal areas, as does the DMN, perhaps drinking the tea puts you in a state slightly closer to animals, which don’t have these areas and can’t do these tasks.
(Caveats: 1. The default mode network doesn’t have sharp boundaries, and even its overall composition turns out to vary depending on the specific instructions given to the patient when measuring it, so it’s hard to be sure what exactly we’re talking about. 2. Animals’ brains are of course very different from each other; here I am thinking of mammals with brains somewhat similar to ours.)
Thanks, Matt. It’s good to have feedback from someone with knowledge in this area. Caveat #1 is well taken. I gather that we have a long way to go in our understanding of the DMN. I’ve seen a lot of speculation along with some doubts about the importance of the subject. This is a tricky area for a science writer. We want to pass along information that’s new and exciting, but we don’t want to stray too far into unproven realms. I try to emphasize the provisional nature of our understanding (and my own very limited expertise) with a lot of “ifs” and “maybes.”
Perhaps I did perform an unwitting experiment with concentration. I wanted to sing along with the hymns, at least the ones in English. Fortunately, the hymns have a lot of repetition, so I could pick up the words after the members sang them a couple of times. I’m good with song lyrics, but I couldn’t remember any of the hymns later in the evening. Just little fragments that came back to me here and there. I was also trying to remember the prayers and stories, but those wound up as little phrases or individual words floating around like chunks in a stewpot.
That experience goes with my general impression that the tea dissolves mental boundaries, although I’m not sure what that means. We definitely need to know a lot more about this subject. It’s wonderful that the research is starting again after several lost decades.