Feelings of regret - thought to be exclusive to humans - have also been discovered in rats, according to a study by the Department of Neuroscience at the University of Minnesota.
"Regret is the recognition that you made a mistake, that if you had done something else, you would have been better off," said A. David Redish, Ph.D., a professor of neuroscience, in a press release. "The difficult part of this study was separating regret from disappointment, which is when things aren't as good as you would have hoped."
For the study, the researchers conducted an experiment on rats to determine their patience levels for certain foods. They measured behavioral and neurophysiological markers that described feelings of regret.
The task was named "Restaurant Row" - a series of four spokes, each presenting a different flavor of food. As the rat accessed each spoke, an audio recording indicated how long the rodents will have to wait to receive that specific flavor of food. The rats had to choose whether to wait for a certain amount of time for the food reward or move onto the next spoke.
Redish compares the experiment to humans when they open the door to a restaurant to see how long it will take to be seated. For example, humans either decide to wait at a Chinese restaurant or choose to go to an Indian restaurant across the road due to long waiting lines at the former dining hall.
The researchers found that the rats that hurried to the next spoke and found a worse flavour, and displayed regretful behavior. However, when rats encountered bad options without making incorrect decisions, such behavior was not present, BBC reports.
Redish said that orbitofrontal cortex, a part of the brain, is active in humans during regret.
"We found in rats that recognized they had made a mistake, indicators in the orbitofrontal cortex represented the missed opportunity. Interestingly, the rat's orbitofrontal cortex represented what the rat should have done, not the missed reward. This makes sense because you don't regret the thing you didn't get, you regret the thing you didn't do," said Redish.
The findings are published in the journal Nature Neuroscience.
