[monkeycantype]

can you be my collective memory for a minute, I remember the existence of a very satisfying engineering explanation for why the representation of various body parts needs to be flipped left/right in the brain that came down to the topology of the wiring, and explained why unflipped isn't feasible / or perhaps it was just less efficient, it was one of those 'mind explodes' moments, but now I can't recall the logic.

[renewiltord]

I recall this. The original idea is from decades ago but perhaps you read it in the Quanta article here https://www.quantamagazine.org/why-the-brains-connections-to... or perhaps that will lead you to what you want.

[monkeycantype]

Ah! That's the thread, not the source I read but I beat if I read the referenced paper I get there , thank you

[ragazzina]

Are you referring maybe to the "Visual map theory"?

https://en.wikipedia.org/wiki/Contralateral_brain#Visual_map...

[monkeycantype]

I wasn't but that's intriguing Thank you

[andrewflnr]

I have a similar dim memory, but (at least according to this article) invertebrate bilaterians don't have that swap at all, so it can't be too strong a constraint.

[bongodongobob]

I always thought it was so if an organism takes head damage on one side, the limbs facing the danger will have a better chance to still work, giving it a better chance to fend whatever off and survive.

[Sharlin]

That would be an incredibly unlikely adaptation anyway, but this change occurred in vertebrates before they even had limbs.

[topaz0]

That has the smell of an evolutionary just so story

[monkeycantype]

no there is a very specific reason, related to mapping the 2d surface of your body to a 2d mapping on your brain that allows the areas of your brain that process sensory input from your skin to be adjacent to the processing of the areas that are adjacent on the skin that only works with a flip, I can remember what that is, I only remember the tingle of understanding it at the time

[jacobsimon]

Curious, let me know if you find anything about it! That does sort of explain why the brain areas would be locally flipped, but maybe doesn’t explain the global flip (right body -> left brain) that the original article is talking about.

[monkeycantype]

I think it's the theory in the article linked just above by renewiltord

[dboreham]

Sort of like an optical projection? (objects projected through a convex lens onto a screen are reversed).