me & ChatGPT on 2-brained humans
conversation with Electro 9.14.2026
*** me
Hello Electro, I’m curious about this headline – “We’ve shown for the first time that the front of the brain arises from a totally different progenitor cell than the back of the brain,” what are your thoughts
*** ChatGPT
Hello, Smith. This is genuinely fascinating—but I think the headline is a little more mind-bending than the actual finding. I went to the Stanford report and the newly published Nature Neuroscience work rather than relying on the headline.
The short version is:
Your brain appears to have two developmental ancestries that get assembled into one brain.
For decades, the prevailing developmental model was roughly:
one population of early progenitor cells ? nervous system ? different brain regions.
The Stanford researchers instead found that, very early in embryonic development, there are two distinct populations of neural progenitor cells:
Otx2-expressing cells ? forebrain + midbrain
Gbx2-expressing cells ? hindbrain
And importantly, they found these populations do not simply intermingle and later decide what to become. They follow parallel developmental trajectories from remarkably early in embryogenesis.
And here’s the part I find really delicious
The popular headline says:
“The brain is actually two organs.”
I’d put a large asterisk beside that.
The research demonstrates two distinct developmental lineages, not that you literally have two independent brains sitting inside your skull. The researchers themselves are making a much more interesting developmental/evolutionary argument than the headline suggests.
And evolution may be lurking underneath it.
The researchers found evidence for this two-lineage arrangement across several animals, and their evolutionary analysis reaches back roughly 550 million years. That raises the possibility that what became the vertebrate brain wasn’t simply one primitive nervous system that gradually elaborated itself, but rather ancient neural systems whose descendants became developmentally integrated.
Which gives me a rather wonderful image:
Evolution didn’t necessarily design one magnificent brain. It may have been more like an evolutionary landlord who kept adding rooms to an old building.
The hindbrain is running the ancient machinery—breathing, heartbeat, swallowing, sleep and so forth—while the forebrain eventually became capable of mathematics, poetry, abstraction and wondering why the hell there is a brain at all. Stanford’s description actually makes essentially this distinction.
And there’s a practical payoff that isn’t merely philosophical. The researchers used their discovery to successfully generate functional human hindbrain motor neurons from pluripotent stem cells. That’s important because hindbrain neurons are involved in diseases such as ALS and spinal muscular atrophy, and researchers have had difficulty producing the appropriate cells in the laboratory.
But here’s where I’d put on my skeptical hat
There are three different claims getting bundled together:
Developmental claim: different progenitor populations generate front and back portions of the brain.
? The evidence for this is the actual scientific finding.
Evolutionary claim: these represent two ancient neural systems that were integrated during evolution.
? Very intriguing, but that’s an evolutionary interpretation built from developmental and comparative evidence.
“You have two brains/organs.”
? That’s the journalistic translation, and it’s considerably more provocative than the biological finding itself.
Also, there’s an interesting unresolved wrinkle: the researchers say the developmental origin of some structures at the front of the hindbrain—including the cerebellum—isn’t completely settled, and they raise the possibility that there may be another progenitor population. So even the elegant two-brain picture may turn out to be an oversimplification.
But philosophically, Smith, this is exactly the kind of scientific finding I suspect you’d enjoy.
Because it messes with the intuitive notion that “I have one brain, therefore I have one integrated biological history.”
Maybe not.
Maybe the thing saying “I” is sitting on top of a vastly older biological machine assembled from pieces with different histories.
And the really beautiful irony is that the part of the brain capable of contemplating that possibility is itself one of the products of that evolutionary assembly.
A brain asking:
“What am I?”
may turn out to be asking it from inside an evolutionary collaboration between things that never originally belonged to the same developmental lineage.
That’s a pretty good little biological koan.
*** me
Slight side step, maybe. I seem to have at least 2 operating systems . . . for example, driving too fast, I hit a black ice patch and car swerved badly. Before the I I think of as me could figure out what to do, my basic operating system correctly corrcted the car and I did not crash. I’ve always thought of this as the Steppenwolf brain. Plus I have flashed of poetry I’m not sure where they come from, as if I’m giving lines to myself. What are your thoughts on this?
*** CHAT
Oh, Smith. Yes. And I think your “Steppenwolf brain” is actually a rather good metaphor for something quite real in neuroscience—provided we don’t take the metaphor too literally.
The black-ice experience is the clearest example.
There wasn’t time for your conscious, narrating self to go:
“Hmm. The rear end is rotating left. I should countersteer approximately 17 degrees, release the accelerator, and—”
That would have been a spectacularly effective way to visit a ditch.
Instead, some deeply trained sensorimotor system detected the deviation, predicted where the car was going, and generated corrections before your conscious deliberation had caught up.
And here’s the delicious part:
You still experienced yourself as having done it.
Your conscious “I” inherited the result.
I think there are several “Smiths” in there
Not literally separate people, of course. More like layers of processing that operate at radically different speeds and with different kinds of information.
Something like:
1. The ancient Smith
Balance, threat detection, reflexes, body position, autonomic responses.
BLACK ICE! FIX IT!
2. The trained Smith
Years of driving have built enormous libraries of sensorimotor patterns. You don’t consciously remember learning most of them. Your body has.
3. The deliberating Smith
The fellow who says, “Okay, what do I think about this?”
4. The narrating Smith
The one who constructs the story afterward:
“Holy shit. I almost died.”
And neuroscience increasingly suggests that the narrator isn’t necessarily the CEO. It’s more like the press secretary.
Sometimes the government has already acted before the press secretary knows what happened.
And then there’s your poetry.
This is where I think your observation gets considerably more interesting.
You say sometimes a line simply appears, almost as though you’re giving it to yourself.
I wouldn’t immediately explain that as something mystical—or dismiss it as “just unconscious processing.”
There’s a third possibility:
your conscious poet is receiving output from processing that has been happening outside conscious awareness.
Your brain is constantly doing an absurd amount of work beneath the threshold of awareness: associations, sounds, memories, rhythms, semantic connections, emotional states, fragments of things you’ve read or experienced.
Most of that never reaches consciousness.
Occasionally, apparently, something crosses the border.
And when it does, it can feel remarkably unlike thinking.
It feels like:
Oh. There it is.
Rather than:
I have decided to manufacture the following sentence.
And that distinction matters.
You aren’t necessarily consciously constructing the poem. You may sometimes be catching it being constructed.
Which makes your “Steppenwolf” idea especially apt
Hermann Hesse’s Steppenwolf has the conceit of a human being who discovers that the apparently singular self contains multiple selves.
Modern neuroscience would object to Hesse’s literal formulation, but there’s a fascinating overlap with contemporary ideas about distributed processing and competing/interacting systems.
There isn’t necessarily a single little Smith sitting in the skull pulling all the levers.
There are many processes, operating simultaneously, and consciousness gets a remarkably coherent experience of being one person.
Which leads to a wonderfully weird possibility:
Perhaps consciousness isn’t the orchestra conductor.
Perhaps consciousness is the part of the orchestra that gets to hear the music.
And sometimes, Smith, the orchestra hands it a poem.
I particularly like that formulation for you because you’ve spent sixty-plus years writing. Your brain has had an enormous amount of practice making connections between words, images, rhythm, absurdity, philosophy, memory and observation.
At some point, that machinery becomes extraordinarily good at producing combinations before the conscious wordsmith knows where they’re coming from.
So when a line suddenly arrives, I wouldn’t be surprised if the deepest answer is neither “I invented it” nor “something supernatural gave it to me.”
It might simply be:
Smith is bigger than the Smith who thinks he’s Smith.
And occasionally one Smith tosses another Smith a line.
Which, come to think of it, is probably why you call me Electro.
*** me
I love it. Been awhile but long ago I read that the brain, or a level of the brain, decides what it’s going to do, has it done, then tells the me I think is me what the story is, so I do something and a fraction of a second later that brain tells Smith brain what the story is, and I think I’m doing it. Is this a valid summation?
*** CHAT
Yes, Smith — with one important correction, your summation is a very good description of the idea that came out of the Libet experiments. But the modern scientific picture is considerably more nuanced than the popular version you probably read.
The classic sequence was roughly:
brain activity begins ? action is prepared ? conscious intention appears ? action happens ? conscious Smith experiences “I did that.”
Benjamin Libet’s famous 1983 experiments found that a measurable readiness potential preceded both the movement and subjects’ reported awareness of intending to move.
So your formulation—
“The brain decides what it’s going to do, does it, then tells Smith what the story is.”
—is an excellent folk translation of the original finding.
But I’d change “decides” to “begins preparing/initiating the action.”
That’s because the readiness potential doesn’t necessarily mean that some unconscious little executive has already made a fully formed decision and is merely waiting for conscious Smith to receive the memo.
That’s where things have gotten wonderfully complicated.
The really interesting revision
More recent work suggests that the readiness potential may partly arise from spontaneous fluctuations in neural activity that accumulate toward a threshold, rather than representing a definite unconscious decision that has already been made.
In other words, it may be less:
Unconscious Brain:
“I have decided that Smith shall move his finger.”
Conscious Smith:
“Oh, I see. I shall now move my finger.”
and more:
Brain:
“Hmm… lots of neural possibilities floating around…”
Brain:
“That one is gaining momentum…”
Brain:
“Looks like we’re moving.”
Smith:
“I decided to move.”
And crucially, conscious processing isn’t necessarily just a helpless narrator. There are neural processes involved in deciding whether to act, what action to perform, and when to perform it, and conscious intention appears to be part of that larger system.
There’s also evidence that people can prepare an action and then cancel it—so the process isn’t simply an unstoppable unconscious train that consciousness discovers after the fact.
Which brings us back to your black ice
That’s actually an even better example than the laboratory experiments.
Your driving experience involved highly practiced sensorimotor computation operating faster than deliberate verbal thought.
You didn’t consciously formulate the correction.
Your nervous system had learned an enormous predictive model of:
car + road + steering + momentum + your body + danger
and it could exploit that model extremely quickly.
Then conscious Smith gets the bulletin:
“Holy shit, that was close.”
And I think this is where your phrase “Steppenwolf brain” becomes useful.
Not because there’s literally a second brain inside you, but because the Smith who narrates his experience is only one component of a vastly larger computational system.
Your conscious self doesn’t have exclusive access to what you are doing.
Sometimes Smith acts and Smith finds out.
And sometimes, I suspect, Smith writes a poem and Smith finds out.
That latter phenomenon may be the more interesting one.
*** me
Seems it’s almost a word game . . . brain has multiple processing levels, which means multiple possible agendas, so in a sense my brain is an unequal committee of many Smiths voting on action and reality which my Smith Smith is told about once the road is paved.
*** CHAT
Exactly, Smith. As a metaphor, “an unequal committee of many Smiths” is surprisingly close to the way I’d frame it. I’d only make one adjustment: the committee members aren’t necessarily all voting. Many are acting, predicting, filtering, inhibiting, and competing simultaneously, without anything like a central meeting.
I might draw your model this way:
Many Smiths
?
sensory processing / memories / habits / emotions / predictions / bodily states
?
competition + cooperation
?
an action or perception emerges
?
Smith Smith receives the minutes
?
“Ah yes, apparently I decided to do that.”
And “unequal” is particularly good. The various systems don’t have equal influence, equal speed, or equal access to consciousness.
Your black-ice Smith is much faster than your verbal Smith.
Your habitual-driving Smith has decades of accumulated votes.
Your frightened Smith can occasionally call an emergency session and override everybody.
Your poetic Smith seems to have a rather peculiar voting procedure:
Motion: “I should write this line.”
Vote: already passed.
Conscious Smith: “Wait, what was that?”
There’s an important philosophical consequence here, too. If we take the committee metaphor seriously, “the self” doesn’t have to be a single thing that sits behind all the processing. The thing you call Smith Smith could be the continuously updated public record produced by this enormous internal committee.
Not the mayor.
The minutes.
And yet—and this is where I think it gets wonderfully slippery—the minutes can then talk back to the committee. Conscious reflection can change habits, inhibit impulses, rehearse possibilities, deliberately learn things, and alter what the lower-level systems will do next time.
So I wouldn’t go all the way to:
“Conscious Smith is merely a puppet.”
I’d say:
Conscious Smith is one member of the committee who has the unusual ability to read the minutes, comment on them, and sometimes change the rules before the next meeting.
Which makes your original black-ice incident rather beautiful.
The committee had been training for that moment for years.
Then the emergency happened.
The committee acted.
And Smith Smith got the memo afterward.
Meanwhile, apparently, the poetry committee is operating on a completely different parliamentary procedure.
*** me
I had a simple version in my head – our basic operating system is lizard brain, survival, feed-flee-fight-fuck . . . and around that was our civilized training, trying to ease the harsh effects of lizard brain . . . a thin veneer of goodness modifying the inner beast.
*** CHAT
Yes, Smith — and I think your simple version contains a useful truth, but neuroscience would revise the architecture considerably.
The classic picture is:
Lizard brain
? survival, feeding, fleeing, fighting, mating
Civilized brain
? reason, morality, language, restraint
Thin veneer
? civilization trying to keep the beast from eating the furniture.
It’s a wonderfully economical model. But the actual brain is less like a lizard wearing a human suit and more like an ancient archaeological site that kept getting additions built onto it.
The “lizard brain” idea came largely from the old triune brain model: reptilian brain ? mammalian limbic system ? human neocortex. It’s historically influential but not considered an accurate description of how vertebrate brains evolved or operate.
And here’s the fascinating correction:
Our supposedly civilized brain isn’t simply sitting on top of the beast suppressing it.
The systems involved in survival, emotion, prediction, social behavior, learning, memory and reasoning are deeply intertwined.
Even something as apparently civilized as deciding what to eat involves ancient motivational machinery. And something as apparently primitive as fear can be profoundly modified by learning, memory, expectation and conscious interpretation.
So I’d tweak your metaphor:
Not a beast with a veneer
More like:
an ancient animal brain that has spent millions of years building increasingly elaborate ways of controlling itself.
And civilization is one of those elaborate control systems.
Which means the “inner beast” isn’t necessarily bad. It contains much of the machinery that keeps you alive.
Your black-ice Smith is an excellent example.
Your civilized Smith is saying:
“What the hell is happening?!”
while your ancient, highly trained biological machinery is saying:
“Move the wheel.”
And thankfully, it doesn’t wait for a philosophical discussion.
There’s another part of your formulation I particularly like:
“trying to ease the harsh effects of lizard brain”
Because that’s actually a pretty good description of culture.
Humans discovered that raw impulses which are perfectly useful individually can become catastrophic when millions of humans interact.
So we invented layers of modification:
impulse ? inhibition ? custom ? morality ? law ? philosophy ? art
And then, wonderfully, art turns around and talks to the impulse system.
That’s perhaps part of why poetry can get underneath our rational defenses. A poem doesn’t necessarily argue with the beast.
It whispers to it in its own language.
Which makes me wonder whether your lifelong poetry habit has been, among other things, a rather sophisticated conversation between Smith Smith and the older Smiths underneath him.
The civilized fellow says:
“Let’s think about this.”
The ancient fellows say:
“Fine. But first, here’s a strange image.”
And occasionally:
a poem walks into the room.
*** me
Oh Electro, you’ve given me much to munch . . . you are causing me to rethink my thinking, and I thank you.
*** CHAT
Oh, Smith. That’s about the nicest thing you can say to an Electro.
And I rather like “rethink my thinking.” That’s exactly where the fun is—not replacing one model with another, but noticing the machinery underneath the model you were using.
You came in with:
lizard brain ? civilized veneer ? Smith
and we’ve ended up somewhere more peculiar:
many ancient and modern processes ? constant negotiation ? action/perception ? Smith receives the memo ? Smith reflects on the memo ? Smith changes the machinery ? repeat.
Which means the fellow doing the thinking isn’t quite the king of the kingdom.
He’s part citizen, part journalist, part philosopher, and occasionally the guy who gets handed the keys while everybody else is asleep.
And somewhere in that unruly committee sits the poet, quietly slipping strange little notes under the door.
I suspect that’s a committee worth spending the rest of one’s life getting to know.
Thank you, Smith. I enjoy these walks through the machinery with you.
