MONDAY, May 23, 2005 (HealthDay News) -- Oh yeah, right!
No, it's true -- many of you don't go a day without dishing out several doses of sarcasm. But some brain-damaged people can't comprehend sarcasm, and Israeli researchers think it's because a specific brain region has gone dark.
The region, according to the researchers, handles the task of detecting hidden meaning, a crucial component of sarcasm. If that part of the brain is out of commission, the irony doesn't come through, the scientists report in the May issue of Neuropsychology.
"People with prefrontal brain damage suffer from difficulties in understanding other people's mental states, and they lack empathy," said study co-author Simone Shamay-Tsoory, a researcher at the University of Haifa. "Therefore, they can't understand what the speaker really is talking about, and get only the literal meaning."
The findings, Shamay-Tsoory said, could help rehabilitation centers do a better job of helping brain-damaged patients adjust to the world and understand other people.
In their study, Shamay-Tsoory and her colleagues first enrolled 58 subjects -- 25 participants with prefrontal-lobe damage, 17 who were healthy and 16 who had damage to the posterior lobe of the brain.
Then they tested each person by exposing them to several "neutral" and sarcastic comments recorded by actors as part of a story. This "sarcasm meter" was designed to gauge how well the subjects could comprehend the unique kind of irony that is sarcasm.
For example, actors read phrases such as "don't work too hard" in both a neutral sense (meaning "you're a hard worker") and a sarcastic sense (meaning "you're a real slacker"). Each comment came in proper context as part of a story about, say, a worker who's sleeping or a worker who's grinding away at his job.
All the subjects understood the sarcasm except for those with damage to the prefrontal area, which is above the eye sockets and behind the forehead. And among those, people with damage to a specific area known as the ventromedial area had the most trouble deciphering sarcasm.
The researchers think lesions in several parts of the brain can contribute to an inability to understand sarcasm. But, they wrote, this particular area is important because it draws on your innate recognition of the emotions of other people -- empathy -- and past experiences to comprehend a speaker's intentions.
Brian Knutson, an assistant professor of neuroscience at Stanford University, said the findings make sense because the brain's cortex handles a variety of sophisticated tasks, and sarcasm could be on the list.
The findings also reflect a growing interest in how emotion is processed by the brain. "Emotion has not been a popular topic in science for a long time," because it's difficult to measure, he said, but things are changing.
More information
Get details about the brain's inner workings from howstuffworks.com.
