Sarcasm Explained? Right.

By DAVID GLENN

Alexander Portnoy famously tries to cope with his hectoring mother's sarcasm in the 1969 novel Portnoy's Complaint by visiting a psychiatrist. Now it turns out that he might have been better off visiting a brain surgeon and getting a few lesions in his ventromedial nucleus.

Three Israeli neurologists reported last month that people with damage in certain regions...