“She lacks the power of conversation, but not the power of speech.”
— George Bernard Shaw

All of us know someone who just doesn’t get it. Now we know where they just don’t get it.
Specifically, we now know that people lose the ability to perceive sarcasm when a part of a brain called the right parahippocampal gyrus is damaged. But you already knew that, didn’t you, Einstein?
The information comes courtesy of recent research by Katherine P. Rankin of the Memory and Aging Center at the University of California-San Francisco.
Sarcasm is a complicated kind of humor. The message it’s meant to convey is the opposite of the language used to convey it. In most cases, sarcasm can’t be understood unless you can reasonably predict what other people are thinking.
It’s not like this stuff is really important or anything, not like it could be used to help diagnose aging-related brain disorders such as semantic dementia, a progressive disease where people forget the meaning of words.
And not like it’s rocket science. Dr. Rankin only used cutting-edge magnetic resonance imaging and a new test called Tasit: The Awareness of Social Inference Test. Duh.
Scientists long have associated the left side of the brain with language. But it turns out that there’s much more involved in understanding non-literal language like sarcasm, jokes and puns.

Before Dr. Rankin’s research, the right parahippocampal gyrus was thought only to play a role in detecting background changes in visual tests. Obviously, there’s more to it than that.
Most big advances in understanding how disease works engender predictions about possible future treatments. In the case of Dr. Rankin’s research, however, the usefulness comes in diagnosing what are called frontotemporal dementias.
Most of us think of dementia, senility and Alzheimer’s disease as being different names for the same thing. But there are important differences in the apparent causes and progressions of those diseases. People with Alzheimer’s, for example, may lose the ability to recognize old friends and family members, but they can perceive sarcasm as well as anyone else.
The sarcastic among us long have dreamed of the day when science could cure the sarcastically challenged. Before that day comes, science must come up with a cure for the common punch in the nose that is sure to follow.