2011/4/20

Burkhard Bilger - The Possibilian: What a brush with death taught David Eagleman about the mysteries of time and the brain. In Eagleman’s essay “Brain Time,” published in the 2009 collection “What’s Next? Dispatches on the Future of Science,” he borrows a conceit from Italo Calvino’s “Invisible Cities.” The brain, he writes, is like Kublai Khan, the great Mongol emperor of the thirteenth century. It sits enthroned in its skull, “encased in darkness and silence,” at a lofty remove from brute reality. Messengers stream in from every corner of the sensory kingdom, bringing word of distant sights, sounds, and smells. Their reports arrive at different rates, often long out of date, yet the details are all stitched together into a seamless chronology. The difference is that Kublai Khan was piecing together the past. The brain is describing the present—processing reams of disjointed data on the fly, editing everything down to an instantaneous now. How does it manage it? … Like Kublai Khan, he says, the brain needs time to get its story straight. It gathers up all the evidence of our senses, and only then reveals it to us. It’s a deeply counterintuitive idea in some ways. Touch your finger to an ember or prick it on a needle and the pain is immediate. You feel it now—not in half a second. But perception and reality are often a little out of register, as the saccade experiment showed. If all our senses are slightly delayed, we have no context by which to measure a given lag. Reality is a tape-delayed broadcast, carefully censored before it reaches us. I think it can be all too easy to toss around accusation that such-and-such theory of consciousness is a “homunculus theory” or “Cartesian theater”. Certainly, many theories of consciousness have to break down at a certain point and say, “Well, and then you just see it.” To be honest, as an undergraduate I myself once labored over a Cartesian theater model in which I thought about consciousness as kid playing an NES. But this is a joke. A writer for the very prestigious New Yorker talking about a well respected neuroscientist quotes him as describing the brain as a king in a castle. Seriously, a king in a castle. That it never occurs to either the scientist or the writer to ask, “Well, wait a minute: if the brain is like Kublai Khan, is there something else that’s like Kublai Khan’s brain?” just goes to show how poorly philosophers have kept in contact with the broader culture. To be sure, it seems unthinkable that someone as interested in consciousness as Eagleman should never have even heard of Daniel Dennett, but apparently absolutely none of what Dennett was trying to argue for caught with him. Perhaps the problem is just that the arguments philosophers are making are too abstract? What does the “homunculus argument” even mean? But even if Eagleman wasn’t interested in the reductionist/eliminitivist/supervenience/anti-reductionist debate surely he should have known some of the very simplest rules of the game—don’t explain the brain as though it had a tiny brain inside of it to do the thinking for it.

Burkhard Bilger - The Possibilian: What a brush with death taught David Eagleman about the mysteries of time and the brain.

In Eagleman’s essay “Brain Time,” published in the 2009 collection “What’s Next? Dispatches on the Future of Science,” he borrows a conceit from Italo Calvino’s “Invisible Cities.” The brain, he writes, is like Kublai Khan, the great Mongol emperor of the thirteenth century. It sits enthroned in its skull, “encased in darkness and silence,” at a lofty remove from brute reality. Messengers stream in from every corner of the sensory kingdom, bringing word of distant sights, sounds, and smells. Their reports arrive at different rates, often long out of date, yet the details are all stitched together into a seamless chronology. The difference is that Kublai Khan was piecing together the past. The brain is describing the present—processing reams of disjointed data on the fly, editing everything down to an instantaneous now. How does it manage it?

…

Like Kublai Khan, he says, the brain needs time to get its story straight. It gathers up all the evidence of our senses, and only then reveals it to us. It’s a deeply counterintuitive idea in some ways. Touch your finger to an ember or prick it on a needle and the pain is immediate. You feel it now—not in half a second. But perception and reality are often a little out of register, as the saccade experiment showed. If all our senses are slightly delayed, we have no context by which to measure a given lag. Reality is a tape-delayed broadcast, carefully censored before it reaches us.

I think it can be all too easy to toss around accusation that such-and-such theory of consciousness is a “homunculus theory” or “Cartesian theater”. Certainly, many theories of consciousness have to break down at a certain point and say, “Well, and then you just see it.” To be honest, as an undergraduate I myself once labored over a Cartesian theater model in which I thought about consciousness as kid playing an NES. But this is a joke. A writer for the very prestigious New Yorker talking about a well respected neuroscientist quotes him as describing the brain as a king in a castle. Seriously, a king in a castle.

That it never occurs to either the scientist or the writer to ask, “Well, wait a minute: if the brain is like Kublai Khan, is there something else that’s like Kublai Khan’s brain?” just goes to show how poorly philosophers have kept in contact with the broader culture. To be sure, it seems unthinkable that someone as interested in consciousness as Eagleman should never have even heard of Daniel Dennett, but apparently absolutely none of what Dennett was trying to argue for caught with him. Perhaps the problem is just that the arguments philosophers are making are too abstract? What does the “homunculus argument” even mean? But even if Eagleman wasn’t interested in the reductionist/eliminitivist/supervenience/anti-reductionist debate surely he should have known some of the very simplest rules of the game—don’t explain the brain as though it had a tiny brain inside of it to do the thinking for it.