THURSDAY, May 20, 2004 (HealthDayNews) -- Regret is a complex emotion that helps guide humans in regulating their individual and social behavior.
It is also vulnerable to injury to the brain, a new study says.
Research appearing in the May 21 issue of Science found that when the region of the brain known as the orbitofrontal cortex was damaged, people no longer experienced regret and couldn't anticipate the consequences of their actions when participating in a gambling exercise.
"If I can rehearse in my head how I will feel if I make the wrong choice, I'll be more careful if I have two alternatives," said study co-authors Angela Sirigu, director of research at The French National Center for Scientific Research in Bron. "In patients with orbitofrontal lesions, they don't care about what happens with alternatives. It looks like this region of the brain is very important for the experience of regret," she said.
For this study, Sirigu and her colleagues recruited five people with damage to their orbitofrontal cortex that occurred during a stroke and 18 people with no brain damage. The study volunteers were male and female and their average age was about 55.
They had all of the volunteers participate in gambling exercises. In each exercise, they were asked to choose one of two wheels. Each wheel contained an arrow that would spin and eventually stop on one of four conditions: +50, -50, +200 or -200 (at the time of the study, the unit of money used was French francs.) In one exercise, the arrow would only spin in the chosen wheel. In the other, both arrows would spin, allowing the study volunteers to see what the outcome would have been had they chosen the other wheel.
After each exercise, the volunteers were asked to rate how happy or sad they felt on a scale of -50 to +50, with +50 being extremely happy.
Not surprisingly, people without any damage to their brains weren't pleased when their decision cost them money. However, Sirigu said, knowing what happened on the other wheel could significantly alter how they felt. For example, if they won 50 francs but the other wheel won 200, they were sad, whereas if they had won 50 and not known the outcome of the other wheel, they would have been happy.
On the other hand, people with orbitofrontal lesions didn't care what happened on the alternative wheel, she said. These people also made no attempt to minimize their future losses, as the healthy people did.
"Regret is important for when we are making a choice to make the good choice," Sirigu said.
She noted people with damage to this area of the brain often behave very differently. She said they tend to make risky choices, don't care if they make the wrong choice, and have problems with social interactions.
In the future, Sirigu said, she is planning on studying the brains of people addicted to risk, such as compulsive gamblers, using scans to see what areas of the brain are activated by these behaviors.
"Orbitofrontal damage robs people of the ability to anticipate the consequences of their actions," said Dr. Elkhonon Goldberg, a neuropsychologist at New York University Medical Center and author of The Executive Brain: Frontal Lobes and The Civilized Mind.
He said this was an interesting study that confirmed the role of the orbitofrontal cortex in emotional control. He added the orbitofrontal cortex is not alone in processing complex emotions, such as regret, and said that if the authors had studied other parts of the prefrontal cortex they likely would have noted differences there as well.
To learn more about how the brain functions, visit the National Brain Tumor Foundation. And here's another article on the orbitofrontal cortex's role in addictive behavior from the U.S. Department of Energy's Brookhaven National Laboratory.