The DMN gives a Who
And why the Default Mode Network (DMN) matters to you.
At the end of The Amazing Spider-Man (2012), Peter Parker’s English teacher postulates there’s only one plot in all of fiction, and really, all of life:
Who am I?
The DMN, that’s who.
What’s the DMN?
The Default Mode Network (DMN) is a system of key areas in the brain: the medial prefrontal cortex (mPFC), posterior cingulate cortex (PCC), precuneus, and angular gyrus, for you brain nerds. It’s in charge of processing information related to yourself, how others relate to you, your personal experiences, and future possibilities.
It’s the system your brain defaults to the moment you finish a task — when you’re wandering from the dishwasher, staring out a streaked window, waiting for your coffee to brew. It’s counterbalanced by the Action Mode Network (AMN), the system activated when you direct attention and action outwards at the world.
And together, they let you give a DAMN: balancing self-referential thought with cognition for action.
Why does the DMN matter?
1) The DMN gives us identity and self-growth.
Douglas Hofstadter, a notable cognitive and computer scientist, subscribes to the notion of the narrative self:
…The idea of the self is ultimately a hypothetical construct — a story our brains spin which generates the illusion that there is a single, stable and unified locus of willing, thinking and choosing which constitutes our ‘I’. We are all like Scheherazade…[O]ur ‘I’ can only be sustained through an act of perpetual storytelling on ‘our’ brain’s part.
(Scott O’Reilly on I Am A Strange Loop, Douglas Hofstadter)
Like in the field of information architecture, we make sense of the mess of our lives with the DMN. More specifically, the DMN is in charge of everything that goes into introspective thinking, self-reflection, and the understanding of others socially, emotionally, and linguistically. In short, the DMN is the self-referential I.
We continuously create and recreate the idea of ourselves in our heads (cognitive reframing, anyone?). This ongoing reexamination of what matters to us and why — the latest trendy issue, the way they ignored me, what‘s in my shopping cart — is enabled by this dynamic interplay of squishy brain parts. And together with the AMN, it shapes the way we move through the world.
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2) The DMN fosters curiosity and creativity.
Beyond the narrative of ourselves, the DMN generalizes to our ability to comprehend, explore, and create stories and ideas.
Curiosity: The PCC and precuneus are the DMN areas that integrate what we pay attention to, our memory, and our surroundings. Researchers found the PCC is more activated when we explore different options and a more enlarged precuneus in curious monkeys (George must have a big one!), linking greater self-awareness to greater curiosity.
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Creativity: One popular model of how the creative process works is the Blind Variation and Selective Retention (BVSR) theory, or more informally, the divergent and convergent thinking found in design’s double diamond.
The DMN is activated during the Blind Variation/divergent thinking phase to generate out-of-the-box ideas (e.g. chopsticks as a hat). Our executive control then kicks in to converge on more realistic possibilities (e.g. chopsticks for Cheetos, as the powers that be intended). Stronger connections between these shows stronger cognitive flexibility and creative potential, both valuable characteristics to develop, no matter who you are.
Emotional regulation: Remember that whole left/right brain neuromyth? Yeah, turns out the DMN is responsible for integrating cognition and emotion across the whole brain, as well as social processing. These functions play a large part in planning adaptive behaviour for the AMN (i.e., for you to take action).
For example, you might run into that friend you secretly hate, but they’ve got that sweet discount at that store you like so you play nice, and hey, they’re actually not that bad after all! That conflict between your gut reaction of “Ugh” and the social pressure of basic human decency gets reconciled by the DMN into your best non-Duchenne smile, at least until you change your mind.
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3) Technology disrupts the DMN.
Several studies have highlighted how social media usage alters users’ brain functions through constant stimulation. It’s especially good at hijacking the DMN that needs boredom to grow and putting the system responsible for processing our relationships with others on overdrive. An unfortunate side effect of our biology is the fact that negative social comparisons activate the DMN more than positive ones do, and this overactivity of negativity can tip the scales between healthy self-care and intense self-rumination.
Additionally, in recent years, people have thrust AI into the roles of life coach, planner, therapist, cheerleader, confidante, partner — a natural outcome of our inherent drive to escape negative feedback for our egos’ sake. Herbie’s story may sound familiar: a telepathic robot, doomed to be an incurable people-pleaser to avoid hurting those who need him. There’s social safety in what you tell AI and what AI tells you; less judgment, more privacy from peers, and you don’t even need to think about potential follow-up questions.
Though there are a few workarounds nowadays to get more truth out of our machines, this default to ease and comfort also comes at the cost of exercising our DMNs.
A weaker DMN means a weaker sense of self and thought. Scaling this up to a societal level, is there reason to worry? We’ve seen plenty of studies so far showing lower neural connectivity in people who heavily rely on AI output, with impacts on creativity, memory, and critical thinking. However, there is room for positivity; paired with expertise and a willingness to engage critically, AI can enhance learning and productivity (hopefully).
But there’s been more than enough commentary on the double-edged sword of technology, so I’ll leave it at that.
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It’s possible to get a DMN.
How do you develop a stronger DMN? Like with everything else in life, practice and a little luck. Beyond the classic lifestyle advice of exercise, sleep, meditation, and journaling, just let yourself be bored sometimes. Let your brain build the random connections it wants, between Nelson Mandela and the inevitability of the multiverse, between horseshoe nails and lost kingdoms, and so forth and so on.
With technology, be intentional. What are the unanticipated consequences of using (or not using) something? Keep your critical thinking sharp — trust, but verify, especially in this age of information and intelligence.
And at the end of it all, keep on answering:
Who am I?
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Want to learn more? I’ve scattered a few links throughout, but here’s some good starting points:
