US scientists find brain’s "funny bone"

"Although the purpose of humor and laughter is still largely unknown despite 2000 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," he said.

Shibata and colleagues released a report at the annual meeting of the Radiological Society of North America that was based on the use of functional magnetic resonance imaging (MRI) to map activity in the brains of 13 people exposed to humor in four different tests.

"There have been few studies of humor’s place in the brain, but understanding the basis of positive emotions will likely be as helpful as understanding the negative ones," he said.

"In the future, scans of brain activity might be used routinely by psychiatrists to assess patients who have mood disorders such as depression, which often is accompanied by a loss of humor," he added.

The study said the brain may help explain why people who suffer a stroke involving the lower frontal lobes of the brain have alterations of personality, including loss of their sense of humor. The same part of the brain is also associated with social and emotional judgment and planning, the study said.