Wednesday, March 31, 1999 Published at 23:52 GMT 00:52 UK
Locating the centre of fun
Decoding the brain has proved no laughing matter
Scientists have located where people's sense of humour lies - at the front of their brain.
People who have suffered injuries to the front of their brain do not get sophisticated jokes and prefer slapstick humour, according to research.
The scientists from the University of Toronto and the Baycrest Centre in Toronto say that, for the first time, they have pinpointed the main centre of humour - in the right frontal lobe of the brain.
"We've always thought of humour as a defining human attribute, but an intangible part of our personality," said Dr Prathiba Shammi of the university's Department of Psychology.
"Now we know humour can be tested and scientifically scrutinised."
The researchers tested humour responses to written and verbal jokes in 31 adults aged 18 to 70.
Twenty-one of them had a brain injury as a result of stroke, a brain tumour or surgical removal of part of their brain.
The study found that people with an injury to the frontal lobe of their brain found it most difficult to appreciate written and verbal jokes and cartoons.
They chose the wrong punchlines to written jokes and were likely to choose totally illogical endings more common in slapstick humour.
For example, they were asked to finish the following joke:
A teenager is being interviewed for a summer job. "You'll get $50 a week to start off," says his boss.
"Then after a month you'll get a raise to $75 a week."
The guinea pigs then had to choose from a range of punchlines:
The second answer was the correct one, but people with damage to their right frontal lobe tended to choose the third punchline.
The researchers say their findings have implications beyond humour.
Previously it was thought that the right frontal lobe was not important for higher cognitive functions and frontal lobotomies were often performed on people with mental health problems.
"Through studies such as this one, we have evidence that the right frontal region plays a critical role in higher cognitive functions such as humour, emotions and personality," said Dr Donald Stuss, who oversaw the research.
"It receives information from almost all other brain regions and integrates multiple types of information."
The researchers say humour requires the ability to remember information, to look at things from a shifting perspective and to think in an abstract manner.
The research is published in the journal Brain.