Wednesday, June 25, 2008

Mahon & Caramazza (2008): A must read for proponents of "embodied cognition"

At the risk of turning Talking Brains into a blog exclusively dedicated to mirror neurons, here is yet another post on the topic. But the fact is, mirror neurons and embodied cognition have become such a dominant force in cognitive neuroscience and psychology, with obvious implications for work on language and brain, that the topic needs to be addressed thoroughly and frequently.

So our latest survey on mirror neurons is in. Forty-five percent of respondents (the majority!) said THE "MIRROR SYSTEM" THE BASIS FOR (I.E., PLAYS THE DOMINANT ROLE IN) ACTION UNDERSTANDING. Another 23% were unsure. Only 30% of respondents actually got the answer right.

This is a bizarre result (although it reflects the dominant view in cognitive neuroscience) because all the available evidence points to the conclusion that the mirror system is NOT the basis for action understanding. Have a look at the speech or apraxia literature and one finds double-dissociations between the ability to recognize actions and produce actions. Either people have not read the relevant literature, or have decided to believe in "mirror system theory" on faith alone.

In case of the former situation, I suggest the following paper as a must-read:

A critical look at the embodied cognition hypothesis and a new proposal for grounding conceptual content

Bradford Z. Mahon, a, b, and Alfonso Caramazzaa, b
Journal of Physiology-Paris
Volume 102, Issues 1-3, January-May 2008, Pages 59-70

Many studies have demonstrated that the sensory and motor systems are activated during conceptual processing. Such results have been interpreted as indicating that concepts, and important aspects of cognition more broadly, are embodied. That conclusion does not follow from the empirical evidence. The reason why is that the empirical evidence can equally be accommodated by a ‘disembodied’ view of conceptual representation that makes explicit assumptions about spreading activation between the conceptual and sensory and motor systems. At the same time, the strong form of the embodied cognition hypothesis is at variance with currently available neuropsychological evidence. We suggest a middle ground between the embodied and disembodied cognition hypotheses – grounding by interaction. This hypothesis combines the view that concepts are, at some level, ‘abstract’ and ‘symbolic’, with the idea that sensory and motor information may ‘instantiate’ online conceptual processing.


Yisrael said...

maybe the mirror neuron system causes us to believe in the mirror neuron system ;)

Brad Buchsbaum said...

at least you're not preaching to the choir!

Anonymous said...

Regarding all these important and detailed critics on the impact of mirror neuron discovery, an already old but interesting reading:

A critical review of PET studies of phonological processing.Brain Lang. 1996 Dec;55(3):317-51.

See the reply in the same issue: pp.352-85.

Controversy, controversy...

Also, regarding a possible mediating role of the motor system in action understanding, more in line with this post, a further reading:

Use-induced motor plasticity affects the processing of abstract and concrete language.Curr Biol. 2008 Apr 8;18(7):R290-1.

Marc Sato

David Poeppel said...

Boy, I am (pleasantly) surprised that the (semi-)old literature is till read, such as old Brain and Language controversies ... :-) Yes, that old one got pretty intense.

Thanks for the reference to the Current Biology paper -- looks very interesting and relevant. The abstract/concrete distinction is used so much -- and yet so useless ... What is the distiction actually about? I have never understood it.

Greg, that can be your next review, debunking abstract/concrete.

Yisrael said...

I'd like to second david's proposal about the abstract/concrete distinction. The truth is, it seems to me, a lot of the dichotomies we use in linguistic experiments really only serve to make the experimenters life easier. grammatical/non-grammatical, metaphorical/literal, concrete/abstract. These all exist on a gradient that is highly effected by context in a lot of cases. I'd be interested in hearing discussion about ways to potentially restructure our theory and consequently our experimental approaches to address this problem.

navi said...

The abstract/concrete distinction seems really artificial and misleading. They merely refer to 'abstract' entities like love, justice, beauty, etc.(for the 'abstract concepts') or 'concrete' entities like chair, car, fruit, vegetable, etc.(for the 'concrete concepts'). But the concepts themselves for both kinds are abstract.