They say laughter is good for the soul. But, as this ScienCentral News video reports, scientists have found out how the brain responds to a good joke.
Laugh It Up
What's happening in your brain when you find something funny? Researchers at Stanford University have discovered that what makes us laugh also activates the reward mechanism in the brain.
"For the first time we know that the reward centers of the brain are explicitly involved in perception of humor," says Allan Reiss, psychiatry professor at Stanford University, director of the Stanford Psychiatry Neuroimaging Laboratory and co-director of the Center for Brain and Behavior at Packard Children's Hospital.
Previously, little was known about what goes on in your brain while you're finding something funny. "While humor clearly involves some aspect of emotion, we felt that other neural systems also must be involved," says Reiss. "In particular, most human beings are 'drawn' to humor; it feels good to be around it —we seem to feel rewarded. We went looking for the reward center [in the brain] because it was our own theory that humor is pleasure." The reward centers of the brain include: the nucleus accumbens or NAcc, which is involved in the rewarding feelings that follow monetary gain or the use of some addictive drugs; the ventral tegmental area, involved in the rewarding effects of drugs and alcohol; and the amygdala, which regulates fear and emotion. Dysfunction in the amygdala has been implicated in disorders such as depression.
To learn more about the mechanism behind humor, Reiss and his team scanned the brains of sixteen healthy volunteers with a functional magnetic resonance imaging (fMRI) machine while showing the volunteers cartoons that were either funny or deliberately made to be unfunny by having their punch lines removed. Afterwards, the participants rated how funny the cartoons were on a scale of one to ten. The scans revealed that the reward centers of the brain were activated when the subjects found a cartoon funny.
Reiss hopes more studies like this will ultimately uncover why disorders such as depression and autism affect or even impair sense of humor. "Loss of one's appreciation of the rewarding aspects of humor is a frequent and fairly specific symptom of depression," says Reiss. "Utilizing studies such as this may be one way to more specifically identify individuals at risk for depressive disorders as well as early response to treatment."
Studying humor also provides insight into behavior. "Understanding humor is fundamental to understanding many aspects of 'normal' human social behavior," says Reiss. "One's sense of humor often dictates if, how, and with whom we establish friendships and even long-lasting romantic relationships. Humor also is a universal coping mechanism when faced with all varieties of stress; as such, humor has significant ramifications for our psychological and physical health."
Reiss has already begun the next phase of his research—investigating the differences between what men and women find funny. This research was published in the December 4, 2003 issue of the journal Neuron and was funded by the National Institutes of Health.