[cbigart]

I'm going to throw out (3) because it doesn't make any sense (to me), and we haven't found any evidence that this is true.

(2) seems possible, but highly unlikely.

(1) seems the most probable of the three options, and although I believe we have found evidence that biological systems exploit quantum effects in some instances, there doesn't seem to be any indication that brains (human or otherwise) use quantum effects for computation.

The thing that you seem to be discounting is that the bulk of the work has already been pre-computed. Our brains can do what they do in 5 seconds * 40 watts because they have been "designed" to do so via billions of years of evolution. In ML terms, the training stage has already happened by the time your brain starts thinking, it is simply doing inference at that point.

[api]

I agree that #1 is by far the most likely. #3 would mean we (meaning natural science) are wrong about the nature of the universe. I included it mostly to get across the mystery we have here, namely that what brains do cognitively on so little power appears to be "impossible" by classical CS metrics.

I think you are incorrect about precomputation though. The human genome is not very large. It's smaller than Windows 10 or Wikipedia. It's also not substantially different from that of a mouse or a chimpanzee. Most of what it encodes is highly conserved metabolic stuff. All the richness of human cognition is realized through a vanishingly small subset of that already small genetic code.

Nearly all learning and cognition happens after birth, meaning it's done by the brain (unless #3) using absurdly less energy than any known method of computation.

[perl4ever]

"The human genome is not very large"

I think this is reflective of a massive blindspot.

A program to print "hello world" isn't very large, but it doesn't compile itself or produce its own operating system or produce the hardware to run the OS to run the compiler...or produce the companies to produce the hardware and software...or produce the economy to produce the companies... Clearly there is information in the compiled program that is not in the source code or the language spec.

[234rwe4]

> The human genome is not very large.

This just means that the "algorithm of intelligence" is not terribly complicated. So we have hope of reverse engineering it.

[api]

That may be the case but I don't think it solves the power mystery. It may be a simple algorithm but it does an awful lot of np-hard/np-complete things on very little power. Among these are absurdly fast learning and fuzzy associative search.