Rats suffer feelings of regret after making a poor decision, in much the same way as humans, new research suggests.
The tiny mammals were subjected to tests in which they were given a choice between several rooms containing different treats. When they chose a compartment containing a less-desirable treat, the rats looked back at the other room, containing the better snack. Researchers equate this with similar actions in humans. When people buy a different car than they really wanted, they tend to look at the automobile of their desire as they leave the lot.
Rats also quickly ate the less-desirable meal quickly, and waited for relatively long periods of time for a chance to eat their preferred food.
Investigation of feelings of regret in rats was conducted by scientists from the University of Minnesota Department of Neuroscience. If confirmed by other studies, this would be the first time feelings of regret have been shown in any animals other than humans. This emotion was once believed to be a uniquely human trait.
"Regret is the recognition that you made a mistake, that if you had done something else, you would have been better off. The difficult part of this study was separating regret from disappointment, which is when things aren't as good as you would have hoped. The key to distinguishing between the two was letting the rats choose what to do," A. David Redish, co-leader of the study, said.
By timing how long rats were willing to wait for their preferred meals, Redish and his team were able to quantify how much the rats desired a meal. Investigators compare their measurement to watching how long people are willing to stand in line at a restaurant before being seated, or whether they walk out the door. The animals, on average, waited longer for certain flavors of food.
Among other information, this behavior suggests the creatures have preferences in taste.
Adam Steiner, a graduate student in neuroscience at the school, was co-leader of the study with Redish. The team based its observations of regret on behavior indentified with the emotion by psychologists and economists.
Rats brains were wired to show what images were going through the minds of the animals. When they appeared to be expressing regret, they imagined entering the other "door" on "restaurant row."
Investigators believe other animals, especially mammals, may also suffer from feelings of regret following bad decisions.
"Regret is something we think of as very human and very cognitive. We're seeing that the rats are much more cognitive than we thought," Redish stated in a press release.
Investigation of possible feelings of regret in rats was published in the journal Nature Neuroscience.