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Comment by jakobegger | Hacker News Reader

Can anybody point me to the papers where scientists have actually "reverse engineered (...) regions of the brain" or present "highly detailed mathematical models of (...) neurons"?

As far as I know, research in those directions is nowhere near as sophisticated as Kurzweil tries to make us believe. The mathematical models for neurons I've seen may reproduce some firing statistics, but they are not at all suitable for actually modelling behavior of a system in response to a stimulus.

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http://www.neuron.yale.edu/neuron/ http://www.artificialbrains.com/openworm http://en.wikipedia.org/wiki/Brain_implant

I'm not sure what you are trying to say with those links. I know that people are working on mathematical models of neurons, it's just that the current models have little in common with real neuronal systems. The only systems that are described nicely are simple systems with very few neurons (eg. reflexes that involve two or three neurons). And more ambitious projects, like the Openworm project you linked to, can't seem to get past preliminary phases...

I'm not sure how you can claim "reflexes that involve two or three neurons" are state of the art or that OpenWorm "can't seem to get past preliminary phases". Neither http://www.openworm.org/science.html nor http://www.i-programmer.info/news/105-artificial-intelligenc... look like a preliminary phase to me. That's a system of more than 300 neurons, fully mapped, simulated and working, both virtually and hooked up to real sensors and actuators.

I guess what I'm looking for is the comparison of the model with experiment. How do the researchers know that they are simulating c. Elegans, and not just an artificial organism inspired by c elegans?

While simulating a human brains should be sufficient to pass the Turing test, that doesn't mean it is necessary.

I completely agree with you.

However, Kurzweil's argument focuses on the fact that he believes we will someday be able to simulate the human brain, and that's something I disagree with strongly.

Saying that we will never be able to simulate a piece of hardware/wetware is a pretty strong statement. (Unless you think there is some kind of magic inside it.)

the obstacle is that systems composed of many simple elements quickly become so complicated that we can't simulate them anymore, even if we would completely understand the individual elements.

But we have working examples of that machine.

The problem is in completely understanding it. If we completely understand it, then it shouldn't be hard to simulate.

i'd argue against that. Somewhere else in this thread someone brought up weather predictions; even though we completely understand the physics of weather, we can't simulate worldwide climate precisely for various reasons (not enough information, not enough computational resources, chaotic behavior). I think it's the same thing with our brain.

I may be wrong, but weather cannot be simulated because real version is running over the complete globe. Brain, while hard to simulate with present technology, still is a 3 pound thing. Computational resources obstacle will be overcome.

I don't think that a human brain, isolated and somehow kept alive, would be able to pass the Turing test. Especially not if it was grown in a tank or something. I might be wrong, of course. The story of Helen Keller seem to imply that very little stimuli is needed to become self-aware and be able to communicate in a meaningful way -- but who can say how important it is to be able to relate, on some fundamental level -- in order to share enough to pass a Turing test?

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