May 29, 2005

Locating the sarcasm bump?

In a significant advance for the modern science of phrenology, Dr. Simone Shamay-Tsoory and others at Haifa University have located the brain regions responsible for "understanding sarcastic comments": the right ventromedial prefrontal cortex. (S.G. Shamay-Tsoory and R. Tomer, "The Neuroanatomical Basis of Understanding Sarcasm and its Relationship to Social Cognition". Neuropsychology, 19(3), pp. 288-300 (2005)). The abstract:

The authors explored the neurobiology of sarcasm and the cognitive processes underlying it by examining the performance of participants with focal lesions on tasks that required understanding of sarcasm and social cognition. Participants with prefrontal damage (n = 25) showed impaired performance on the sarcasm task, whereas participants with posterior damage (n = 16) and healthy controls (n = 17) performed the same task without difficulty. Within the prefrontal group, right ventromedial lesions were associated with the most profound deficit in comprehending sarcasm. In addition, although the prefrontal damage was associated with deficits in theory of mind and right hemisphere damage was associated with deficits in identifying emotions, these 2 abilities were related to the ability to understand sarcasm. This suggests that the right frontal lobe mediates understanding of sarcasm by integrating affective processing with perspective taking.

I shouldn't be too sarcastic here -- the paper is interesting and suggestive. However, it exemplifies the tendency of scientists to assume without discussion that the common-sense categories of conscious experience must be in one-to-one correspondence with brain regions and with components in a functional "boxology". (And often with genes as well, though that's a different story.) So when I read a paper whose second section heading is "The Anatomical Basis of Sarcasm", I get a sinking feeling: here we go again.

There's a compelling critique of neo-phrenology in Martha Farah's 1994 article, "Neuropsychological inference with an interactive brain: A critique of the locality assumption", Behavioral and Brain Sciences, 17, 43-61. Plenty of others, before and since, have highlighted the problems that arise when we reason uncritically from lesion effects or from subtractive functional imaging to the functional and anatomical locality of some mental process or content. This is not to say that brain function is homogeneous, or that it is necessarily wrong that the right ventromedial prefrontal cortex "mediates understanding of sarcasm by integrating affective processing with perspective taking".

The BBC News story about this publication is significantly less credulous than the BBC norm, using phrases like "scientists say", and moderating the suggestion that these "findings might help to explain autism features" with quotes from the National Autistic Society that "The causes of autism are still being investigated", and that "Many experts believe that the pattern of behaviour from which autism is diagnosed may not result from a single cause".

I learned about this from Justin Busch at Semantic Compositions, who has posted an interesting discussion of some other aspects of the paper, especially the authors' claim that the sarcastic passages in their experiments were read with "sarcastic intonation". Justin linked to an old post of mine, which offered an alternative to Steve Pinker's theory of "could care less" as sarcastic. He didn't link to the posts where I criticized the idea that such a thing as "sarcastic intonation" actually exists at all (here, here and especially here), and this reminded me again of the lack of a topical index to Language Log.

I still don't have any general solution to that problem, but here is a list of our posts on sarcasm:

Reverse sarcasm? (Mark Liberman)
Scalar inversion and the unique cephalopod of negation (Mark Liberman)
How does the devil admonish Kerberos? (Mark Liberman and David Beaver)
Improve your love life through the power of pragmatics (Mark Liberman and David Beaver)
The FCC and the S-word (again) (Mark Liberman)
Aw+ (Mark Liberman)
From Just So Stories to science, in biology and in pragmatics (Mark Liberman)
Lederer should care less (Eric Bakovic)
Caring less with stress (Mark Liberman)
Still on the hook (Eric Bakovic)
"Could care less" occurs more (Mark Liberman)
Negation by association (Mark Liberman)
Speaking sarcastically (Mark Liberman)
Most of the people in the world could care less (Mark Liberman)
Caring less all the time: a variant of the etymological fallacy, and some cautions about the pragmatics-phonetics connections (Arnold Zwicky)

I should also cite the Second Law of Pragmatodynamics (from Duding out): "In all isolated cultural exchanges, irony increases."

Posted by Mark Liberman at May 29, 2005 10:03 AM