[thangalin]

The human brain has between 100 and 500 trillion synapses and consumes a lowly 12 watts. (In contrast, a 12.6 megawatt supercomputer, in 2013, took 40 minutes to simulate one second of biological brain activity.)

The article cites 250 billion synapses per watt.

For the same 12 watts as a human brain eats up, a set of memristors could simulate three trillion synapses. A cat, in comparison, has 10 trillion. To get 100 trillion synapses, multiply those 12 watts by 33.3 to get 400 watts (the draw of nearly seven 60-watt incandescent bulbs).

Since one watt bags us 250 billion synapses and 400 watts is equivalent to a memristor-based human brain, then 400 cm^2 is the area needed to emulate the meekest of human minds.

That's nearly the same area as half of a medium Domino's pizza.

Certainly is... food for thought.

[sz4kerto]

"In contrast, a 12.6 megawatt supercomputer, in 2013, took 40 minutes to simulate one second of biological brain activity."

Just as a note: we are not sure whether that large computer really simulated brain activity or not. The tricky thing in brain research is that we have practically zero* idea about what matters and what can be omitted from the simulation. (For example, the glia cells seem to be important -- until recently, we have disregarded their role.)

So at this point even we had an infinitely big computer we could not simulate the brain properly because we don't know what exactly to simulate.

*zero means that there's much more we don't know than what we know.

[samatman]

As I never tire of quipping, if you can't get it high on neurotransmitters, it isn't a neural network.

[dkersten]

"In contrast, a 12.6 megawatt supercomputer, in 2013, took 40 minutes to simulate one second of biological brain activity."

Not really a fair comparison. That's like simulating one processor with another and complaining that 1 second of activity took 40 minutes to simulate. If we can implement the NN directly, rather than simulate it, we should expect a much smaller performance gap.

If your calculations are correct, that doesn't sound so bad. If we could implement a brain-sized (by number of neurons) neural network in the area as half of a medium Domino's pizza, that seems like a damn good achievement to me!

[abstractbeliefs]

Remember though that the brain seems to be a rather modular structure. While the total area is quite big, we could probably get a lot of mileage out of much smaller subsystems taking care of only, say, visual pattern recognition, or speech analysis, in much smaller dies.

[voteforchange]

Someone should read Catherine Malibou and Francisco Varela :-)

Neuroscience is already bored with not only subsystems, the holistic nature of the brain, but also the notion of the brain as the body's sole processor of cognition.

[mda]

Brain synapse response time is very slow. Depending on type it is in order of milliseconds.

[vanderZwan]

I guess that's part of why such a large part of our thinking is subconscious parallel processing: as a workaround for this technical limitation.

[e12e]

The thought of a drone with the intelligence of a cat is a scary thought...

The numbers are interesting, though. 400 square centimetres sounds to me to be in the ballpark of a human brain (accounting for several layers).

[rbanffy]

> The thought of a drone with the intelligence of a cat is a scary thought...

And I immediately imagined drones going around the landing gears of bigger planes demanding their attention...

[neolefty]

Does that take into account computation speed per synapse/memristor?