A Belated Response

by Will Wilson

John raises a number of good points in his response to my post about modularity. First of all, I should have been more careful to make clear that I'm not making a claim anywhere near as strong as "differing cytoarchitecture between brain regions implies that different cognitive functions are localized to those regions" -- besides, cytoarchitecture is a tricky thing.

My point with Brodmann's areas was merely that given strong evidence for soft modularity coming out of experimental psychology, and given that neurons in differing areas of the brain seem optimized for different sorts of processing, Occam's razor should suggest that this is at least an area worth investigating. The real evidence that specific cognitive functions inhere to specific regions comes from the lesion studies which test this hypothesis. While I'm intimately (as in having to wade through this trash every time I pick up the NYT Science section) aware of the shoddy experimental methods employed by nearly everybody in the field, the sheer volume of results suggests that some functions at least are strongly localized with minimal inter-subject variability.

Regardless, I don't think a lot hangs on this point.

John took issue with my saying that hard modularity is unimportant from a philosophical point of view. The misunderstanding, I think, revolves around the different usages of the word "intelligible". I suspect that John is using the word in the "not a black box, can ultimately be reductionistically explained"-sense, whereas I'm using it in the "can soon be readily grasped by human beings"-sense. Salemicus is correct in his comment on my original post. Hard modularity could potentially make all kinds of dystopian fMRI horrors appear right around the corner, but it's soft modularity that makes the idea even remotely plausible to begin with (or does it?). The point here is that that the question of whether mind-stuff is homogeneous and undifferentiated is far more philosophically important than the question of whether brain-stuff is homogeneous and undifferentiated -- even though it's the latter, or rather the connection between the two, that freaks out the good folks at The New Atlantis.

Finally, I'd like to briefly reply to the latter half of Salemicus' comment by pointing him at this study. Creepy, I know, but I think more importantly that it's a good example of why positing a "decision" or "self" module doesn't get us out of the philosophical binds that soft modularity sticks us in. It seems like the brain just doesn't work that way; and if you don't believe me then there's a bunch of neuroscientists in Germany who'd love to play poker against you.

I'm a reluctant optimist, so I don't think this means we need to jettison free will or the soul anytime soon. What it does mean, however, is that something a little more nuanced than naive dualism is required here.

P.S. Those as obsessed as I am by the implications that some form of reductionism/compatibilism will have for the concept of personal identity are well advised to read everything by this guy -- starting with "Reasons and Persons."

Comments

[John]

Thanks, Will. I think we're actually largely in agreement here, though perhaps the extent of our differences will be clearer if I recommend that it's actually this guy who's got the final word on reductionism and the mind. Good luck wading through that.

But I agree with you that what you're calling soft modularity is actually the most interesting thing. I also agree that (real and artificial) lesion studies - as opposed to brain scans - are the most reavealing source of evidence when it comes to questions of hard modularity. However, I think that it's very important to be careful in moving from the observation that certain brain regions are especially causally relevant to specific cognitive functions to the claim that those functions "inhere to" (as you say) those regions. All that's required for the brain, and the mind/brain relationship, to be intelligible in the ways it needs to be is for the former sorts of claims to be true - and thankfully so, since the latter usually strike me as incoherent, false, or at least wildly undersupported.