Thread

Two parallel neural ectoderm progenitors contribute to the developing brain

137 points · 80 comments · Jimmc414

carefree-bob · 1789760305 · focus · HN ↗
There was a book in the 1970s called "The Origin of Consciousness in the Breakdown of the Bicameral Mind" by Julian Jaynes, where he argued that ancient civilizations -- and he used examples from Homer -- lacked the current modern sense of self-consciousness. If you look at their behavior, they interact with some external divine voice that drives their actions, whereas if you read modern literature you see people being driven by an inner voice which they associate with themselves.
This shift from the "bicameral mentality" of the external voice to the modern mentality of the inner voice was hypothesized by Jaynes to be rooted in some biological changes in the brain. At the time there was split brain research that showed these two parts of the brain function independently almost as two different minds in the same skull. See this 2007 survey: <a href="https://www.researchgate.net/publication/6323702_The_bicameral_mind30_years_on_A_critical_reappraisal_of_Julian_Jaynes'_hypothesis" rel="nofollow">https://www.researchgate.net/publication/6323702_The_bicamer...
1. crooked-v · 1789760851 · focus · HN ↗
  > they interact with some external divine voice that drives their actions
  ...in a specific region, in a specific time period, immediately before the economic and then societal crash of the eastern Mediterranean that changed culture in the region forever.
  The hypothesis breaks down pretty hard when you realize he just kind of handwaves away people in the rest of the world not having any kind of abrupt cut-over in the styles of recorded literature that forms the backbone of his arguments.
  1. ViktorRay · 1789761037 · focus · HN ↗
    Are you sure about this? If you look at the ancient stories in India you can similar phenomena
    carefree-bob · 1789761237 · focus · HN ↗
    Yes, Jaynes used a comprehensive approach, albeit one rooted in literature. I only threw in "Homer" as an example to be clear that "ancient civilizations" referred to bronze age and before, and that this was not the Joe Rogan kind of ancient civilizations.
    glenstein · 1789767539 · focus · HN ↗
    I think the trouble is once your category is loosey-goosey enough it could be open-ended to the point that anything can fit it.
    The fact that overall of recorded history you can find instances of any sort of interaction with something that's felt to be a voice that's independent from one's own subjectivity is open-ended to the point that it can fit the literary and cultural history of basically any civilization on Earth.
    What would be more impressive is some additional specificity, any sort of evolutionary mechanism, and any sort of supporting biological data. Otherwise the thing that is being described here isn't a theory, it's barely even vibes. This is to vibes what vibes are to coherently formed thoughts.
2. ProjectArcturis · 1789761054 · focus · HN ↗
  Okay but this article is about evolution hundreds of millions of years ago.
3. someguynamedq · 1789762329 · focus · HN ↗
  This is pretty fuzzy and woo woo
  1. plusfour · 1789769275 · focus · HN ↗
    It's one of the craziest, most interesting books i've read on the mind. He makes a much stronger argument than can be summarized in a comment. He takes you on a wild journey you are surprisingly ill-equipped for.
    And as this complexity develops, there is the first unsureness, the first need for personal gods to intercede with the higher gods, who seem to be receding into the heavens where in one brief millennium they will have disappeared.
4. general_reveal · 1789762886 · focus · HN ↗
  [dead]
5. vor_ · 1789763187 · focus · HN ↗
  It was a successful pop-sci book when it came out, but its conclusions continue to be met with a lot of skepticism today.
  1. simon-b · 1789763996 · focus · HN ↗
    It's also explored in Neal Stephenson's "Snow Crash", which I assume many here have read. Interesting ideas that are probably more at home in fiction.
    adolph · 1789770525 · focus · HN ↗
    And Iam McGilchrist in The Master and His Emissary nearly 20 years after Stephenson.
    <a href="https://en.wikipedia.org/wiki/The_Master_and_His_Emissary" rel="nofollow">https://en.wikipedia.org/wiki/The_Master_and_His_Emissary
6. dinobones · 1789763579 · focus · HN ↗
  Not relevant to the article.
  Also, that study is extremely dubious/barring on fan-fiction.
  Homer (if he was even a person) recited oral epic poetry (that we've lost most of) and we've written down an extremely lossy version of it.
  Why should we take any of the mythical character's interactions with mythical gods as any insight for the brains of real humans???
  It'd be like year 4000 historians citing World of Warcraft claiming the Lich King is a very obvious example that humans lack an internal monologue because he was not able to distinguish his own motives/actions between Ner'zhul/Arthas (both spiritual entities inhabiting the "Lich King" body).
  1. glenstein · 1789767170 · focus · HN ↗
    I mean I definitely disagree with the book's argument, and you're right that it's making a different argument than the article, but I think straight up declaring it irrelevant is coming in way too hot. It's also an argument for a merging of separate mental structures that's sourcing the change in an event from recent natural history.
    Again, I don't agree with the book's argument, but declaring an argument proposing a similar convergence on the basis of entirely different reasons to be not even mentionable in response to the article is just getting way too overzealous with comment section policing.
    hn_throwaway_99 · 1789768634 · focus · HN ↗
    Uh, no.
    The premise (and this is how the GP comment put it) was that humans around Homer's time had fundamentally different brain structures, and that differences in poetry and thinking processes could be explained by looking at how brains changed over the last few thousand years.
    That's not "overzealous comment section policing". It's rejecting a premise that is completely infeasible with everything we know about human evolution (or relative lack thereof) during that timespan.
    glenstein · 1789769219 · focus · HN ↗
    Uh, yes. It's overzealous because personally disagreeing with something doesn't mean that it's outside the scope of the subject matter that the article is speaking to. If anything, you're reaffirming the commonalities between the theory and what's proposed in the article because what they have in common is a proposed difference in brain structures followed by a convergence.
    The fact that you disagree with the truth of the theory has literally nothing to do with whether it's on point in response to an article that's about the same subject matter. I would have hoped that me saying multiple times that I disagreed with it would have made clear already that there's more going on here than just a matter of whether you do or don't disagree with it. Declaring that it's "not overzealous" mirrors my language back at me but without attaching an actual argument to it.
    graemep · 1789838509 · focus · HN ↗
    What could plausibly cause that change in just a few thousand years?
    I cannot see how this could be true without it following that not everyone will have this change as it is far too recent to have spread to everyone every where. Where are these people who lack it?
    glenstein · 1789843990 · focus · HN ↗
    My read was that they were also disagreeing with it (and I personally disagree with it too for exactly the reasons you mention).
    But the problem in this case isn't just that it's right or wrong, it's that it at least belongs to a related family of arguments that are fair game to explore in response to the article. Some of the best conversations take the form of knowing something is wrong but powering through the struggle of putting the why into words, and all the associated conversational branching that can happen along the way.
    jibal · 1789801794 · focus · HN ↗
    "too hot" and "way too overzealous" is ad hominem, and talking about comment section policing is remarkably hypocritical -- you're actually telling someone not to make certain sorts of comments, which pointing out that something is not relevant to the article doesn't do. Your "not even mentionable" is a complete fabrication -- the comment from dinobones said nothing of the sort. Your whole shtick about "getting way too overzealous with comment section policing" is a complete fabrication -- a projection of what you are doing onto a simple factual statement. And your "Uh, yes" comment below is more obnoxious trolling and attacking strawmen.
    My immediate reaction to the comment about Jaynes's book and the split brain was that it's not relevant to the article, and it conflates three very different things. The comment omits the crucial fact that the split brain research was on people whose corpus collosum had been cut -- no surprise that "these two parts of the brain function independently" since they were no longer attached to each other (which is the complete opposite of what TFA is about). Jaynes's hypothesis was not related in any way to that research, and neither are related in any way to TFA. As someone else noted: "Okay but this article is about evolution hundreds of millions of years ago." -- the clear implication being that Jaynes and split brains aren't relevant. But if anyone actually dares say so, here comes the too hot overzealous comment section policeman to project his own attributes onto them.
    And this is completely aside from whether Jaynes's argument is valid ... you saying multiple times that you disagree with it is also utterly irrelevant and reflects one of several fundamental errors in logic in your comments. But criticisms of your comments is not "comment section policing" -- how absurd ... and dinobones didn't even do that in simply saying that a comment wasn't relevant to the article ... only in your head was "and therefore you are not allowed to post it here". Presumably the comment was made in good faith. I can even grant the same about yours, with a bit of straining and extraordinary charity.
    I won't respond further.
7. [deleted] · 1789764122 · focus · HN ↗
  [deleted]
8. nkrisc · 1789764683 · focus · HN ↗
  That would imply a biological change in all humans in the last ~3000 years after humans had already dispersed across the entire globe?
  That means whatever the change was would have to had occur simultaneously in separate populations all over the world within almost no time at all.
  1. mitxela · 1789777380 · focus · HN ↗
    Not necessarily, could be a change in environment. E.g. teaching people to read by imagining a voice in their head teaches them the voice is their own.
    It's probably BS though.
    nkrisc · 1789777873 · focus · HN ↗
    That’s not a biological change.
    mitxela · 1789781502 · focus · HN ↗
    Learning anything biologically changes your brain.
    rnewme · 1789785069 · focus · HN ↗
    So basically "Reflections on Trusting Trust"? Children of changed society are also changed?
    mitxela · 1789785437 · focus · HN ↗
    Obviously? That's why we all grow up addicted to tiktok now, when we didn't 30 years ago.
    nkrisc · 1789814330 · focus · HN ↗
    Writing and reading existed before the Ancient Greeks, including China and Mesoamerica.
    graemep · 1789838155 · focus · HN ↗
    That also implies isolated populations would not have the same sense of consciousness until they gain literacy or whatever else has that effect?
    If consciousness results from language and culture then some cultures will lack it.
  2. LargoLasskhyfv · 1790013677 · focus · HN ↗
    Something like Toxoplasma Gondii, or similar behaviour modifying parasites, spread by migrating birds?
9. drdaeman · 1789783633 · focus · HN ↗
  It’s an interesting book for sure, but I had (minor, but still) issues even with the introductory premises. Just a few notes I made from the very first chapter:
  - Jaynes used the term “reminiscence” in a way very different from Ballard and claimed no animal is capable of reminiscence. That was a very odd claim overall.
  - Then he claimed that if we ever create a language that can express everything, metaphors won’t be possible. Which is, I think, almost obviously false, because many metaphors are constructed artistically, despite having exact terms.
  - And he talks about spatialization as a primitive aspect of consciousness, but he seems to talk about relations/connectedness at best.
  And so on - I misplaced my notes somewhere and only recovered a few random bits. Still, interesting reading, fun (albeit really questionable) core idea, but those papercuts were kinda off-putting for me.
10. spragl · 1789804738 · focus · HN ↗
  His theory was that the two brain halves communicated through inner voices. Wernickes Area, on the left side, communicated with the similar area on the right side. WA is where we comprehend speech, so Jaynes theorized that was why bicameral people experienced the communication as inner voices.
  The research in the new research paper is about a split between front and back of the brain. So something entirely different. That split is an old idea. Jaynes would most likely have known about it. But it wasnt part of his theory.

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