The ENGINEER's Weblog

Can a thinking, remembering, decision-making, biologically accurate brain be built from a supercomputer?

jauxelin:

“Neuroscience describes the brain from the outside. It sees us through the prism of the third person, so that we are nothing but three pounds of electrical flesh. The paradox, of course, is that we don’t experience our matter. Self-consciousness, at least when felt from the inside, feels like more than the sum of its cells. “We’ve got all these tools for studying the cortex,” Markram says. “But none of these methods allows us to see what makes the cortex so interesting, which is that it generates worlds. No matter how much I know about your brain, I still won’t be able to see what you see.”

Some philosophers, like Thomas Nagel, have argued that this divide between the physical facts of neuroscience and the reality of subjective experience represents an epistemological dead end. No matter how much we know about our neurons, we still won’t be able to explain how a twitch of ions in the frontal cortex becomes the Technicolor cinema of consciousness.

Markram takes these criticisms seriously. Nevertheless, he believes that Blue Brain is uniquely capable of transcending the limits of “conventional neuroscience,” breaking through the mind-body problem. According to Markram, the power of Blue Brain is that it can transform a metaphysical paradox into a technological problem. “There’s no reason why you can’t get inside Blue Brain,” Markram says. “Once we can model a brain, we should be able to model what every brain makes. We should be able to experience the experiences of another mind.”

(…)

“Rendering cells is easy, at least for the supercomputer. It’s the transformation of those cells into experience that’s so hard. Still, Markram insists that it’s not impossible. The first step, he says, will be to decipher the connection between the sensations entering the robotic rat and the flickering voltages of its brain cells. Once that problem is solved—and that’s just a matter of massive correlation—the supercomputer should be able to reverse the process. It should be able to take its map of the cortex and generate a movie of experience, a first person view of reality rooted in the details of the brain. As the philosopher David Chalmers likes to say, “Experience is information from the inside; physics is information from the outside.” By shuttling between these poles of being, the Blue Brain scientists hope to show that these different perspectives aren’t so different at all. With the right supercomputer, our lucid reality can be faked.

“There is nothing inherently mysterious about the mind or anything it makes,” Markram says. “Consciousness is just a massive amount of information being exchanged by trillions of brain cells. If you can precisely model that information, then I don’t know why you wouldn’t be able to generate a conscious mind.” At moments like this, Markram takes on the deflating air of a magician exposing his own magic tricks. He seems to relish the idea of “debunking consciousness,” showing that it’s no more metaphysical than any other property of the mind. Consciousness is a binary code; the self is a loop of electricity. A ghost will emerge from the machine once the machine is built right.”

 

^{Courtesy of BBP/EPFL; rendering by Visualbiotech}

(via jauxelin-deactivated20120217)

Posted 1 year ago — 75 notes