Wednesday, October 19, 2005

Ned Block is a bad ass

I was fortunate enough to catch the talk given by Ned Block yesterday in the philosophy department here. Ned Block is a philosopher of mind/cognitive science from NYU. He's really really famous. Probably one of the most famous active philosophers, hence he's at NYU. Ha. Or is it that NYU has the best philosophy department because people like Ned Block are there? Funny huh?

Anyway, he gave a really great talk about reductionism. At least that's how I read it. The talk was really about the functionalism/physicalism debate in the philosophy of mind, and he argued for physicalism, therefore I imagine he might be a reductionist about mental phenomena.

After just posting about John Bickle's work I thought this was pretty cool. My roomate and I, Brian, had a brief discussion about reductionism and Brian made the objection that reductionism doesn't fly because our folk psychological concepts, so to speak, our feelings that we use in everyday life to communicate etc., don't map onto brain states very well. This is known as the 'multiple realizability' objection. In other words, when two people say they're sad, we assume they are experiencing something similar, but it turns out, so says Brian, that their brains aren't really doing the same thing at all. A given mental kind, e.g. sadness, is multiply realizable by many different brain states. Therefore we shouldn't be reductionists. Or something like this. I'm sure I'm missing some important points, but that's the general gist.

Well, Ned Block seemed to argue that this objection doesn't necessarily hold because our understanding of the brain isn't sophisticated enough. He went through a bunch of terribly cool examples from recent neuroscience work. The example that was most striking to me, at least the one I latched onto, was about early blind people and braille reading.

People who go blind early in life seem to co-opt their visual cortex to read braille. In other words, the part of the brain usually used for seeing, is used for tactile tasks in blind people. This has been forwarded by some philosophers as an objection against physicalism. Mental states don't map onto brain states. We can use a part of the brain typically used for seeing, for feeling.

Block showed, however, that in other experiments it seems that the visual cortex isn't so much for seeing as it is for spatial navigation. For example, one of the experiments used a special tool to zap the visual cortex in an early blind person while they were reading braille. While they reported that they were still feeling the braille, they weren't able to actually read it.

Similarly, when people (I'm not sure if they were blind or not) were feeling a series of ridges on a plastic sheet, they were asked to report if they were feeling the ridges and what there orientation was. When the visual cortex was zapped, they could still feel the ridges, but not detect their orientation, i.e. running up down or left right etc.

While I may have gotten that last part wrong, that's the general gist.

There were some important objections made though. Namely Colin Allen and Johnathan Weinberg were a little concerned with Block's investment in old metaphysical questions.

Johnathan said, "why don't we just let the metahysics slough off like so much dead skin?" Indeed.

Anyway, I am now endlessly fascinated with the philosophy of neuroscience.

Seeing great talks like that is really encouraging. John Earman's talk last year, another really famous philosopher, was equally uplifting, even if I didn't understand much of what he said.

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2 comments:

Unknown said...

I'll bet the Missourian's back hurts!

Anonymous said...

ned block is my uncle.... and he is bad-ass.