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Comment by mindcrime | Hacker News Reader

Why do we need to know how the brain works? We didn't build flying machines by creating artificial birds with flapping wings... likewise, nobody says we need to replicate wetware in order to create useful AI tools.

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we did have physics to help build those machines, models that describe the world in which planes can fly.

we are lacking 'mind physics' at the moment, all we have is brute force trial and error

Well, there's also observations from neuroscience. CNN's were directly inspired by observations of closely-grouped neurons firing when detecting certain images, and capsule networks are directly inspired by cortical columns.

That's a fair point. And I don't mean to argue against continuing to try and understand how the brain works. But I don't think we should take "we don't know how the brain works" as a final argument against being able to build useful kind of AI.

We seem to be lacking a theory of aerodynamics for neural networks. Most research seems to be judged by performance. The Aerodyanmic equivalent focusing on building a more powerful engine rather than wing design. The fact that we still visualize all the spurious w_ij weights in a network is a symptom of this problem. You wouldn’t show a fully connected circuit diagram for an 8 bit adder with spurious logical connections, but this is exactly what we do when we visualize NN topologies.

There’s some great work in Artificial Gene Networks that tries to tackle this problem. AGNs are mathematically the same as ANNs.

Here’s a paper I wrote in 2008 with about 170 citations that has a lot of relevant references: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2538912/

I often see this metaphor as misleading somehow.. In both cases ( birds and airplanes) the physical phenomenon is exactly the same: lifting effect, which is related to the Venturi effect.. that is: the speed and the pressure of a fluid (in this case, air) depends on the geometry of the components affecting the flow of the fluid. Note that the wing geometry in airplanes is actually similar to the birds.. (of course, airplanes have it optimized by CFD for the speed and altitudes they flight) Although the “flapping” in birds’ wings also alters it’s geometry the main function is to act as the engines...

So, yeah, we need to discover the basic physical principle of the brain.

It's not a perfect metaphor, no. But pointing that out doesn't prove that we need a detailed understanding of how the brain works in order to build useful AI tools. Of course I think it goes without saying that more and deeper knowledge of how the brain works is desirable and would be useful. I'm just saying that that kind of knowledge isn't necessarily required in order to achieve useful ends.

Keep in mind the context of what I'm saying, which is responding to this:

Hinton's caught up in a mind boggling batch of mumbo-jumbo that proves no one understands how the brain actually works

I would argue that modern AI/ML is far past "mumbo jumbo" and provides useful tools, even without a detailed understanding of the brain.

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