Psychologists are beginning to map anatomy of humor

Study indicates sense of what's funny resides in right frontal lobe


WASHINGTON -- Amid all the marvelous things we humans can do with our big brains -- multiply fractions, write sonnets, design Web pages -- none is quite so mysterious as our ability to enjoy a good joke.

That's largely because few scientists have bothered to investigate how humor works.

Now, though, two Toronto psychologists say they've pinpointed the part of our brain largely responsible for our ability to understand a punch line and turn it into a hearty laugh.

The fact that their work is being published in the journal Brain today, April Fool's Day, they say, is merely a happy coincidence.

The team conducted its search for the seat of humor by observing how 31 men and women, some with minor brain damage and some with healthy brains, responded to jokes.

Brain damage in general was not a killjoy.

No smile or laugh

But people with damage in one specific area -- the right frontal lobe -- had trouble understanding jokes that required making verbal connections and "had absolutely no smile or laugh" even if they did understand the jokes, said the study's lead author, psychologist Prathiba Shammi.

Instead, they appreciated only obvious, slapstick humor.

A handful of earlier studies, including one in which people wore caps to measure their brain waves as they took in jokes, have pointed to the right side of the brain as the place where jokes are understood.

A few medical cases of patients who burst into spontaneous giggling with no apparent cause turned up tumors in the frontal lobe that hijacked the humor response.

And anecdotal reports from neurologists suggest that patients with frontal lobe damage sometimes tell inappropriate, off-color and silly jokes, said Donald Stuss, a professor of psychology at the University of Toronto and the Baycrest Center for Geriatric Care, who is co-author of the study.

Stuss and Shammi conducted the study not because they were particularly interested in humor, but because they wanted to know more about the frontal lobes, structures that are highly developed only in humans and are among the least understood areas of the brain.

"I call them the black hole of human neuroscience," said Art Shimamura, a professor of psychology at the University of California at Berkeley who said using humor was a "very clever" way to investigate the frontal lobes.

For decades, the frontal lobes were considered a "silent region" because many people with damaged frontal lobes were still able to function normally and hold jobs.

"But it didn't make sense that part of the brain that's most evolved in humans would be silent," said Shammi. Newer research shows the frontal lobes may be crucial to the most complex and human of behaviors, including our ability to sift through memories, rein in inappropriate impulses and, Stuss speculated, share a joke.

"Humor is one of the highest of human brain attributes," he said of the decision to study a topic that many of his colleagues consider frivolous. "How do you get at what a person is? We think looking at humor is one way."

Coordinating center

What role might the frontal lobes play in humor? Well, if you dissect a joke -- as these scientists were happy to do -- you'll find it involves taking in linguistic information, sifting through memories, making comparisons and solving problems.

Once that heavy lifting is done, there's still the task of connecting the intellectual knowledge with our emotions so that mere words can set off a smile, a giggle or a guffaw.

The frontal lobes fit the task perfectly. What little is known of them suggests they are a site where information from throughout the brain and emotional responses are integrated.

"This area of the brain can make lots of those connections," said Stuss.

While the frontal lobes may play a pivotal role in processing jokes, the study's authors cautioned against oversimplifying either the brain or humor by concluding that the brain has a single humor center. Other workers in the fledgling field of humor science agreed.

"It takes a whole brain to appreciate humor," said Peter Derks, a psychologist at the College of William and Mary who has conducted studies of brain waves and humor.

The study also sheds light on the anatomy of humor. The more simple, slapstick humor that the patients with frontal lobe damage enjoyed mirrors the humor most enjoyed by young children, whose frontal lobes are not fully developed.

It's also more similar to the type of humor enjoyed by men.

Studies of gender differences in humor show that women are more likely to enjoy jokes that brain-damaged patients couldn't understand, those involving longer narratives, personal information and memories.

Men, however, are more likely to enjoy humor our scientists would term slapstick: The Three Stooges, men in drag, bare backsides and flatulence jokes, said Regina Berreca, a professor of English at the University of Connecticut and an expert on humor.

"I would hate to say that male humor is the humor of the impaired or the infantile, but since science seems to indicate this is true, how can we argue against it?" she asked.

Does this mean all men are brain-damaged?

"I'm not going to comment on that," said Stuss. "It would give women too much ammunition."

Pub Date: 4/01/99

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