Regret moving to Minneapolis MN

Remorseful rats

When we realize that we did wrong or made the wrong choices, we feel regret and remorse. This feeling is considered to be typically human - it has not yet been proven in animals. But US researchers have now discovered for the first time evidence that rats can also feel remorse. In the experiment, their behavior and brain activity indicated that these rather unpopular rodents can also feel regret if they have made the wrong decision. Accordingly, repentance is not a purely human feeling.

Disappointment sets in when we realize that our expectations have not been met - our counterpart reacts differently than we hoped or an investment turns out to be a flop. But that's not a regret, as Adam Steiner and David Redish from the University of Minnesota in Minneapolis point out. "We feel regret when we realize that the disappointed expectations are our own fault - the result of a wrong decision or action." Repentance is more complex than mere disappointment: It requires that you address the decisive situation or action remembers and understands the connection to the consequences. Studies with imaging methods show that the orbitofrontal cortex is particularly active in humans - an area of ​​the brain that is important for decision-making and the formation of expectations. This area has a similar function in other mammals. However, it was previously unknown whether animals are capable of real remorse.

Patience tests in the "Restaurant Row"

To answer this question, Steiner and Redish developed a special experiment for rats. In one arena, the rats were able to enter four separate zones, each with a type of food waiting for them. However, this food was not directly accessible; instead, a tone sounded when entering this zone. Its height showed the rats how long they had to be before the feeder becomes active - the higher the tone, the longer the waiting time. The length of the waiting time changed at random, regardless of the zone, food or behavior of the rats. The highlight: The rats were only allowed to spend a certain time in the "Restaurant Row" each day. “The time a rat spends waiting in one zone therefore takes away the time to look for food in other zones,” explain Steiner and Redish. During the entire time in the arena, brain waves were recorded in the orbitofrontal cortex of the rats.

As the first rounds showed, there was a threshold value for the rats' patience: if they entered a zone with a tone that was too high - meaning a waiting time that was too long, they left this zone almost immediately. The willingness to wait was higher, however, the more popular the food was. The rats are apparently weighing up whether the waiting time is worthwhile with regard to the food reward to be expected, the researchers concluded.

Signs of regret

It got exciting when a rat decided against waiting, only to find an even longer waiting time for poorer food in the next zone. “This means that the rat made a wrong decision: if it hadn't stopped in the previous zone, it would have received better food in less time,” the researchers explain. In a person, this would be a classic situation that evokes remorse and regret. But was this also the case with the rats? As the researchers report, there is actually evidence of this: in this situation, the rats looked back at the previous zone with a striking number of times. In addition, their patience threshold also changed in the next zones: They were now ready to accept longer waiting times without breaking off the attempt. The brain activity also changed: in the orbitofrontal cortex, the brain waves showed the same pattern as in the feeding zone, which the rats had left too early - as if they were mentally replaying this situation.

“Our results suggest that the rats actually felt something similar to human remorse,” the researchers state. In their opinion, both the behavior and the brain activity of the animals indicate that it is not a matter of mere disappointment, but that the rats recognize their previous decision as wrong. "You look back and regret a missed opportunity," said Steiner and Redish. If this is confirmed, humans would not be the only animal that can feel remorse.


© - Nadja Podbregar
June 8, 2014