Once we can build a brain, we will certainly be able to make another one that is bigger, but that won’t make it better. “Given this arrangement of neurons, what firing patterns will develop” is almost a completely different task than “given this problem to solve, what arrangement of neurons will best solve it”, which itself is merely a footnote to the task of “wait, what are our definitions of ‘problem’ and ‘best’ again?”
Nature scaled chimpanzee brains up by creating billions of them and running them through millions of years of challenging environments; that’s many orders of magnitude more difficult than building a single brain, and the result is merely expected to be whatever works best in the testing environments, which may or may not resemble what the creators of those environments want or expect.
Once we can build a brain, we will certainly be able to make another one that is bigger, but that won’t make it better.
It is very likely that it would, IMHO.
Nature scaled chimpanzee brains up by creating billions of them and running them through millions of years of challenging environments; that’s many orders of magnitude more difficult than building a single brain [...]
Nature had already done the R+D for buillding a partly-resizable brain, though. Turning a chimp brain into a human brain was mostly a case of turning a few knobs relating to brain development, and a few more relating to pelvis morphology. There is no good reason for thinking that resizing brains is terribly difficult for nature to do—at least up to a point.
Could you define how we make a brain “bigger”? Do we replace every one neuron with 2, then connect them up the same way? Without a specific definition there’s nothing but handwaving here, and it’s my contention that finding the specific definition is the difficult part.
But more shockingly: do you really have evidence that the last six million years of human evolution was “turning a few knobs”? If so, then I would very much like to hear it. If not, then we seem to be operating under such divergent epistemologies that I’m not sure what else I can productively say here.
Could you define how we make a brain “bigger”? Do we replace every one neuron with 2, then connect them up the same way? Without a specific definition there’s nothing but handwaving here, and it’s my contention that finding the specific definition is the difficult part.
That would be model-specific. Since we don’t actually have the model under discussion yet it is hard to go into details—but most NN models have the number of neurons as a variable.
But more shockingly: do you really have evidence that the last six million years of human evolution was “turning a few knobs”?
I didn’t claim that the last six million years of human evolution was “turning a few knobs”. I referred explicitly to changes in the brain.
I was mosly referring to the evidence from genetics that humans are chimpanzees with a relatively small number of functional genetic changes. Plus the relatively short time involved. However, it is true that there are still some thirty-five million SNPs.
There’s other evidence that nature’s brains are relatively easy to dynamically resize. Dwarfism, gaintism and other growth disorders show that nature can relatively easily make human-scale brains of variable size—at least up to a point. Even kids illustrate that point pretty well. It does not require a lot of evolutionary R+D to make a brain bigger or smaller—that R+D was done by evolution long ago—and what we now have is resizable brains.
If all we wanted was to triple human brain size just like Nature can, we’d be breeding more whales. And if tripling brain size inherently tripled intelligence, we’d be asking the whales for their opinions afterwards.
If increasing brain size instead merely provides enough raw matter for other changes to eventually mold into improved intelligence, then it doesn’t just matter how hard the size increase is, it also matters how hard the other changes are. And at least in nature’s case, I reiterate that the improvement process was several orders of magnitude harder than the one-brain process. We might be able to do better than nature, but then we’re no longer talking about “it was easy in nature, so it will be easy for us too”, we’re talking about “it was hard in nature, so it might be hard for us too”.
Nature does seem to be able to scale brains down without the millions of years of evolution it took to scale them up, but that at least makes perfect sense as a pre-evolved characteristic. Accidents and poor nutrition are ubiquitous, so there’s a clear selection pressure for brains to develop to be robust enough that restricted growth or damage can still leave a functional result. Is there any similarly strong evolutionary pressure for brains to develop in such a way that opportunities for increased growth produce a better-functional result? If so it may not have been enough pressure; supernormal growth opportunities do seem to exist but aren’t necessarily positive.
And at least in nature’s case, I reiterate that the improvement process was several orders of magnitude harder than the one-brain process.
If we take “time” as a proxy for “difficulty” we have:
Origin of life: 3500 MYA.
Origin of brains: 600 MYA.
Origin of chimp-human split: 7 MYA.
According to those figures, scaling brains up a few thousand times was much easier than making one in the first place. Scaling one up by a factor of 3 was much, much easier.
As for modern big human brains, the main examples I know of arise from giantism and head binding.
Once we can build a brain, we will certainly be able to make another one that is bigger, but that won’t make it better. “Given this arrangement of neurons, what firing patterns will develop” is almost a completely different task than “given this problem to solve, what arrangement of neurons will best solve it”, which itself is merely a footnote to the task of “wait, what are our definitions of ‘problem’ and ‘best’ again?”
Nature scaled chimpanzee brains up by creating billions of them and running them through millions of years of challenging environments; that’s many orders of magnitude more difficult than building a single brain, and the result is merely expected to be whatever works best in the testing environments, which may or may not resemble what the creators of those environments want or expect.
It is very likely that it would, IMHO.
Nature had already done the R+D for buillding a partly-resizable brain, though. Turning a chimp brain into a human brain was mostly a case of turning a few knobs relating to brain development, and a few more relating to pelvis morphology. There is no good reason for thinking that resizing brains is terribly difficult for nature to do—at least up to a point.
Could you define how we make a brain “bigger”? Do we replace every one neuron with 2, then connect them up the same way? Without a specific definition there’s nothing but handwaving here, and it’s my contention that finding the specific definition is the difficult part.
But more shockingly: do you really have evidence that the last six million years of human evolution was “turning a few knobs”? If so, then I would very much like to hear it. If not, then we seem to be operating under such divergent epistemologies that I’m not sure what else I can productively say here.
That would be model-specific. Since we don’t actually have the model under discussion yet it is hard to go into details—but most NN models have the number of neurons as a variable.
I didn’t claim that the last six million years of human evolution was “turning a few knobs”. I referred explicitly to changes in the brain.
I was mosly referring to the evidence from genetics that humans are chimpanzees with a relatively small number of functional genetic changes. Plus the relatively short time involved. However, it is true that there are still some thirty-five million SNPs.
There’s other evidence that nature’s brains are relatively easy to dynamically resize. Dwarfism, gaintism and other growth disorders show that nature can relatively easily make human-scale brains of variable size—at least up to a point. Even kids illustrate that point pretty well. It does not require a lot of evolutionary R+D to make a brain bigger or smaller—that R+D was done by evolution long ago—and what we now have is resizable brains.
If all we wanted was to triple human brain size just like Nature can, we’d be breeding more whales. And if tripling brain size inherently tripled intelligence, we’d be asking the whales for their opinions afterwards.
If increasing brain size instead merely provides enough raw matter for other changes to eventually mold into improved intelligence, then it doesn’t just matter how hard the size increase is, it also matters how hard the other changes are. And at least in nature’s case, I reiterate that the improvement process was several orders of magnitude harder than the one-brain process. We might be able to do better than nature, but then we’re no longer talking about “it was easy in nature, so it will be easy for us too”, we’re talking about “it was hard in nature, so it might be hard for us too”.
Nature does seem to be able to scale brains down without the millions of years of evolution it took to scale them up, but that at least makes perfect sense as a pre-evolved characteristic. Accidents and poor nutrition are ubiquitous, so there’s a clear selection pressure for brains to develop to be robust enough that restricted growth or damage can still leave a functional result. Is there any similarly strong evolutionary pressure for brains to develop in such a way that opportunities for increased growth produce a better-functional result? If so it may not have been enough pressure; supernormal growth opportunities do seem to exist but aren’t necessarily positive.
(edited to fix broken link)
If we take “time” as a proxy for “difficulty” we have:
Origin of life: 3500 MYA.
Origin of brains: 600 MYA.
Origin of chimp-human split: 7 MYA.
According to those figures, scaling brains up a few thousand times was much easier than making one in the first place. Scaling one up by a factor of 3 was much, much easier.
As for modern big human brains, the main examples I know of arise from giantism and head binding.