Sarcasm & Brain Structure

Interesting article from May 23, 2005 New Scientist about research into brain structure and sarcasm:

Different parts of the brain must work together to understand sarcasm, new research suggests. The prefrontal cortex - a small area in the front of the brain - seems to play the biggest role and may integrate the literal meaning of a phrase with the speaker’s emotional intent. The findings on the anatomy of sarcasm could have implications for understanding personality changes in people with brain injury or disease.
“Decision making, emotional processing, empathy, and theory of mind all appear to be involved in understanding sarcasm,” says lead researcher Simone Shamay-Tsoory, a neuropsychologist at the Rambam Medical Center in Haifa, Israel.
Previous research has shown that people with damage in the prefrontal cortex (PFC) have difficulty understanding non-verbal aspects of language like tone, says Richard Delmonico, a neuropsychologist at the University of California at Davis, US.
Researchers studied 25 participants with damage to their prefrontal lobes, 16 participants with damage in the posterior lobes, and 17 healthy controls. They assessed people’s ability to understand someone else’s emotional state by testing how well they could recognise different facial expressions and tone of voice.
To determine if participants understood sarcasm, researchers read a sarcastic and non-sarcastic version of a story and asked participants what the speaker meant in each situation. They also tested ‘theory of mind’ - the ability to understand another person’s frame of mind - by determining if people could recognise when a story contained a “social faux-pas”.

It is, when you think about it, quite amazing that we can understand each other with the complexity of sarcasm added to the equation. How, exactly, do you know that someone is being sarcastic? There's clearly some information provided by the sarcastic speaker that helps you figure that out. Sometimes, you figure it out because otherwise the statement makes no sense. And look how complicated it gets to understand sarcasm in email, where you have no tone at all!