[DaFranker]

Arithmetic savants and trained arithmeticians can come a lot closer to the calculator, showing that the usual human brain layout and/or architecture is a really poor fit for performing this type of calculations.

There's also some evidence that the "efficiency" of the more powerful parts of animal brains (including humans) simply comes from a sort of n-dimensional conditional railroading, which would work like this if my understanding is correct: if you map (B/W) visual inputs to XY axes of a slice of neurons, then when a line is formed, this fires up a line of neurons, which allows a direct connection between the Z±1 neurons of the first and last neurons on the mapped line, so this connection becomes the line. These Z±1 neurons have pathways to various other nearby other potential Z±1 neurons; a connection lighting up between Z±1 neurons that don't have a straightline connection over the XY map could detect different shapes. Then the Z±1 layers and their connections could be creating highway maps between both Z±2 neurons and diagonally-offset neurons that don't "fit in the grid" we're imagining here (remember, we're in 3D and neurons don't form a homogeneous grid, so this is all abstraction anyway).

These second-level connections, arguably identifying something like shapes, have connections in such a way that the next level up detects something else, etc. (insert magic we don't understand), until the detection results in recognizing a specific object, while the side-channel connections we haven't mentioned yet but kept occurring at every level connect to a different side-channel ZY map for, say, the position of the object (with its own layers of processing that eventually connect to the object concept neuron so that the "position" is associated with the recognized object), and/or perhaps other side-channel maps or parallel XY mappings for various other things. And of course, a lot of these things connect to completely different parts that we ignore here, and a lot of the information indirectly makes its way to the conscious mind in this way; the brain doesn't compile a complete vision report and submit it to the conscious mind in one download, it's all using the same hardware.

[kefka]

In essence, in order to figure out the brain, we would need to figure out how a single neuron actually works.

I think that will take us 500 years, give or take a few.

[LesZedCB]

Why do you think that would be the case?

You could say the same about every tool that we use, which we don't totally understand. It just needs to work.

[DaFranker]

No, we wouldn't need this. How we could come to figure out and understand "the brain"[1] without understanding its smaller components is worth several science classes mostly involving maths, most of which I haven't mastered and thus won't arrogantly attempt to explain. We've managed to figure out other complex systems without understanding their components in detail. For one point of comparison, we'd already had a pretty good idea of how inertia and motion worked (Newton's laws) long before we understood in detail the atoms and forces acting upon/between them.

Then there's also the problem of your estimate. 500 years is a rather exaggerated timeframe. Twenty years ago I could've had the most prominent field experts tell me humans would never in the next three hundred years figure out biology even for the simplest of living organisms, because they were simply too irreducibly complex for that. And then a few years ago we simulated an entire worm's nervous system and gave it enough of a body for it to use, move around, and receive input from its entirely-fictional environment. Now we've got people working on doing the same thing with a cat brain. We're nearing breakthroughs in creating fully-synthetic, fully-functional animal organs that you can essentially real-life drag'n'drop to replace a failing natural organ without complications.

Knowing the above, are you really sure it's not 15 rather than 500 years?

[1]. (which is about as meaningful as saying we understand "weather", which is really a huge messy amalgam of many completely unrelated things ranging from fluidic motion and thermodynamics all the way to plate tectonics and even anthropology, after a fashion)