Sarcasm center of brain located
New research from Johns Hopkins University has found that damage to a specific area of the brain could explain why stroke patients can’t recognize sarcasm.
Researchers examined 24 stroke survivors who experienced damage in the right hemispheres of their brains. Those with damage to the right sagittal stratum, an area that connects a variety of brain regions that process auditory and visual information, were less likely to perceive sarcasm.
Additionally, the researchers wanted to further examine previous findings that linked the brain’s cortex to difficulties processing sarcasm by determining if white matter tracts (brain areas that relay information between brain regions) also played a role. So the scientists took MRI images of the 24 patients’ brains and looked for damage in eight white matter tracts. The stroke patients were then given a sarcasm test, including 40 sentences spoken either sincerely or sarcastically.
Processing sarcasm is a complex process for the brain, since it must first understand the literal meaning of the words being heard before detecting the components of sarcasm- including pitch, brief pauses, extended syllables, and variations in volume. It’s not a huge surprise that a stroke could alter this complicated process.
The results, published in the journal Neurocase, found that five of the patients had significant damage to the right sagittal stratum and they correctly answered only 22 percent of the sarcasm statements. In general, people in the general population identify 90 percent of sarcastic statements correctly.
The researchers said that caregivers for stroke victims should be aware that they may have difficulty understanding sarcasm.