According to a new study published in the journal Nature Neuroscience, rats can feel regret – a cognitive behavior once thought to be uniquely human.

“Regret is the recognition that you made a mistake, that if you had done something else, you would have been better off,” said Prof David Redish from the University of Minnesota, who is the senior author on the study.

“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.”

To measure the cognitive behavior of regret in rats, Prof Redish and his co-author, Adam Steiner of the University of Minnesota, developed a new task that asked rats how long they were willing to wait for certain foods.

In this task, named Restaurant row, the rat is presented with a series of food options but has limited time at each ‘restaurant.’

The findings show rats were willing to wait longer for certain flavors, implying they had individual preferences.

Because the scientists could measure the rats’ individual preferences, they could measure good deals and bad deals.

Sometimes, the rats skipped a good deal and found themselves facing a bad deal.

Prof Redish explained: “in humans, a part of the brain called the orbitofrontal cortex is active 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.”

The results of this study allow neuroscientists to ask additional questions to better understand why humans do things the way they do.

By building upon this animal model of regret, future research could help scientists understand how regret affects the decisions humans make.

______

Adam P Steiner & A David Redish. Behavioral and neurophysiological correlates of regret in rat decision-making on a neuroeconomic task. Nature Neuroscience, published online June 08, 2014; doi: 10.1038/nn.3740