Missing out on better food options causes rats to experience regret, proving to be the first time that regret has been identified in mammals other than humans, a Nature Neuroscience press release reported.
Situations were created by researchers where rats had to choose whether to wait a set amount of time for a food reward, or move onto another one.
The rats that decided to move on and ended up finding a worse offering portrayed regretful behavior, BBC News reported.
Dispelling the belief that regret is unique to humans, the study suggests that thoughts similar to regret can affect the future decisions rodents end up making.
Professor David Redish, from the U.S.-based research team, said it was important to differentiate regret from disappointment.
"Regret is the recognition that you made a mistake, that if you had done something else, you would have been better off," he said.
"The hard part was that we had to separate disappointment, which is just when things aren't as good as you hoped. The key was letting the rats choose."
When experiments were carried out where the rats encountered bad options without making incorrect decisions, such behavior was not present, according to BBC News.
"In humans, a part of the brain called the orbitofrontal cortex is active during regret. We found that in rats recognizing that they made a mistake, their orbitofrontal cortex represented the missed opportunity," Prof Redish said.
"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."
This animal model of regret can now be used to help understand how regret affects the decisions humans make, Professor Redish believes.
The study was conducted by neuroscientists based at the University of Minnesota, with their findings reported in Nature Neuroscience.
