Showing regret for making the wrong decision is no longer a behavioral trait exclusive to human, Rats too show regret after making wrong choices, a new study suggests. Such an emotion has never been found previously in any other mammals apart from humans. The study was conducted by neuroscientists based at the University of Minnesota, US; their findings are reported in Nature Neuroscience.
To measure the cognitive behavior of regret, A. David Redish, Ph.D., a professor of neuroscience in the University of Minnesota Department of Neuroscience, and Adam Steiner, a graduate student in the Graduate Program in Neuroscience, conducted a task named “Restaurant Row,” in which they allowed rats to enter chambers containing different food options. They taught rats to go into a contraption called “restaurant row” that had four different sections serving various flavors of pellets at different intervals.
Each rat had a threshold based on their taste preference, and Steiner and Redish used those thresholds to see what was a “good deal” and what was a “bad deal,” and what happened when the rat passed over a good deal. The researchers found that when a rat skipped a good deal and went to a bad deal, they would stop and look at the restaurant they had bypassed. “It looked like Homer Simpson going, ‘D’oh!'” Redish told Wired. “It’s like waiting in line at the restaurant,” Professor David Redish, of Minnesota University, told BBC Nature News. “If the line is too long at the Chinese restaurant, then you give up and go to the Indian restaurant across the street.”
According to the study, published in Nature Neuroscience on Sunday, the rats’ willingness to wait for their ideal choice implied that they had individual preferences. In addition, the researchers also examined the rats’ brain activity, which helped them conclude that the animals indeed experienced regret over the decisions they made while choosing their food.
“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,” 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.”
The researchers believe that the study’s findings will help them better understand why humans act a certain way and how the feeling of regret affects their decision making. The researchers also said that other mammals may also have the ability to feel regret because they have brain structures similar to those of rats and humans, LiveScience reported.