Thursday, March 6, 2008

Comment on Conceptual Organization from Mike Bonner

I (GH) got a nice email from Mike Bonner, who is in Murray Grossman's lab at Penn. There is some useful information here including highly relevant citations, so I'm passing it along, with Mike's permission. Thanks Mike!

Hi Greg,

I'm a grad student in Murray Grossman's lab. I enjoy reading your Talking Brains blog. You've brought up many of the same issues that I and others in Murray's lab have with the semantic memory literature. I just read your March 4th post. You finished with:

"What kind of evidence do we need to really settle the issue? I would say that a convincing finding would be something like lesion (or TMS) evidence that when a person damages the lip area of motor cortex, they lose the concept KISS. Is there any such evidence out there?"

I'm glad that you raised this point It's exactly the issue that I'm hoping to address in my thesis work. I'm writing up a prelim now. I wanted to point to this Pulvermuller TMS study, which may be of interest to you:

Pulvermüller F, Hauk O, Nikulin VV, Ilmoniemi RJ.
Functional links between motor and language systems.
Eur J Neurosci. 2005 Feb;21(3):793-7.

They facilitate speed of response on lexical decision for leg words by activating what should be the leg area of motor cortex. Their results for arms words are a bit dubious though.

There's also a study suggesting that a deficit for concepts (both verbs and nouns) involving manipulation knowledge correlates with damage to hand motor areas of cortex:

Arévalo A, Perani D, Cappa SF, Butler A, Bates E, Dronkers N.
Action and object processing in aphasia: from nouns and verbs to the effect of
Brain Lang. 2007 Jan;100(1):79-94.

Furthermore, results of action knowledge deficits in MND and of reversal of the concreteness effects in SD may be relevant (corresponding with damage to motor (MND) or visual areas (SD)). The upshot for me is that the evidence is still insufficient. I'd love to know if you come across any other relevant studies.

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