Rats feel regret over decisions just like humans, according to University of Minnesota study

Updated June 09, 2014 22:23:24


Scientists have done an experiment using food treats to entice rats into a food station where they could either wait for a meal or go to the next stop.


It is the first time it has been shown that mammals other than humans experience regret.

Dr David Redish, a professor in the department of neuroscience at the University of Minnesota, says scientists are beginning to understand the emotions of rats.

"Regret is a recognition that you've made a mistake; it's an error in your agency," he said.




"We found differences both in the behaviour and in the neurophysiology when the rats were in regret-inducing situations."

'Rat restaurant' experiment reveals regret

The researchers trained the rats to do a task called restaurant row. The rats would run around a square and at each corner there was an exit which led to a food station.

Each food station gave a different flavoured meal. There was cherry, chocolate, banana and plain.


Dr Redish says it's a bit like entering a Chinese restaurant and seeing a long line.

"When you leave the first restaurant to go to the second one you don't know how long the line's going to be at the second restaurant. So what happens if you essentially leave a pretty good line, you know, a short delay, and find yourself now facing a long delay?" he said.

"You could have done better by actually taking the better deal first, and that's your mistake. And so that's the key is that the rats then recognised when they had missed that first deal, that good deal, and now faced a bad deal."

'What might have been'

Dr Redish says it can be hard to read the emotion of regret in the rats.

"It's hard to tell on the face to be honest, but what they do is they'll stop and they'll look backwards but your body stays forwards," he said.

"It looks like somebody going, 'oh man, I messed up", and then after they do that they turn back forward, and they're actually much more likely to stick around for the bad deal after they've messed up on the good deal.

Audio: Rats have regrets too, says study (PM)

"The real proof of the regret was in the neurophysiology, which was that when the animal came to that turn to look back, we actually saw that its orbital frontal cortex - which is the part of the brain that in humans is active during regret - that same part of the brain in rats represented what it should have done.

"It was the might have been ... 'I could have done that'."

Often the human experience of regret is not the things you did not get but rather the things you did not do. The study goes some way in showing a rat's experience of regret is much the same.

"This means that we can start to ask these questions about what are the mechanisms of these decision-making components that, you know, are similar, and of course also what are different," Dr Redish said.

"We know that the rats express regret. We know that they behave differently in these situations and we know that it has consequences down the line. But we don't know whether they avoid regret."

Dr Redish says his study, published in Nature Neuroscience, opens up further questions about rodents' emotions.


"We don't know whether rats can avoid regret or not. It's a very interesting question."

Topics: animals, animal-welfare, emotions, research, animal-science, science-and-technology, human-interest, united-states

First posted June 09, 2014 19:13:30