This is real old but I fucking love it anyway: http://www.medscape.com/viewarticle/412229
Researchers may have found the location of sense of humor in the brain, according to their presentation at the 86th Scientific Assembly and Annual Meeting of the Radiological Society of North America (RSNA) in Chicago, Illinois.
Humor appreciation appears to be based in the lower frontal lobes of the brain, a location associated with social and emotional judgment and planning, according to imaging research. That might explain why people who have suffered strokes involving the lower frontal lobes of the brain may have alterations of personality which include loss of their sense of humor.
"A small part of the frontal lobes appears critical to our ability to recognize a joke," said Dean K. Shibata, MD, assistant professor of radiology at the University of Rochester School of Medicine in New York, and principal investigator of a study using functional magnetic resonance imaging (fMRI) to map activity in the brain while it is registering humor. "Although the purpose of humor and laughter is still largely unknown despite 2,000 years of speculation, having a sense of humor is a key part of our personalities and it can play a powerful role in balancing negative emotions, such as fear.