Mar 11, 2020 08:00:00

Rats can also understand the pain of others, but when they get more treats, they prioritize themselves.

Human beings are able to engage in '

altruistic behavior ' that seeks to benefit others without regard for their own losses. This altruistic behavior is a type of physiological phenomenon caused by brain activity, and it is said that animals other than humans also engage in altruistic behavior. A research team at the Dutch National Institute of Neuroscience (NIN) has shown in an experiment that ``mice, like humans, can choose altruistic behavior based on their brain functions.''

Harm to Others Acts as a Negative Reinforcer in Rats: Current Biology
https://www.cell.com/current-biology/fulltext/S0960-9822(20)30017-8

Rats avoid hurting other rats
https://phys.org/news/2020-03-rats.html

The research team placed two cages next to each other and placed a mouse in each cage. Then, we prepared two levers in one of the baskets and created a device where ``if you press either lever, you will get a snack.'' After the mouse learned that ``if you press a specific lever out of two levers, you'll get a treat,'' scientists discovered that when the mouse presses the lever that releases the treat, a weak electric shock is sent to the floor of the neighboring basket. I rewired it as follows.

The rats learned that they could get a treat by pressing a specific lever, but when they realized that the rat next to them was receiving an electric shock, they stopped pressing the lever that gave them a treat. thing.

According to the research team, there were individual differences in the strength of the reaction, with some rats getting frightened and stopping pressing the lever the moment they noticed that the next rat was receiving an electric shock, while others stopped pressing the other lever. There were some rats who pressed the lever, and some who stopped pressing the lever but did not show any signs of movement.

In addition, when the same experiment was carried out under conditions where the amount of snacks given as a reward for pressing the lever was tripled, it was found that the rat next to him continued to press the same lever even if he received an electric shock. While rats can choose altruistic behavior, when a certain standard is exceeded, they choose ``selfish behavior'' that prioritizes their own interests.

Functional magnetic resonance imaging (fMRI) has shown that when humans empathize with the pain of others, the anterior cingulate cortex of the brain becomes active. So, when they injected a local anesthetic into the rat's brain to reduce activity in the same area as the human anterior cingulate cortex, they found that the rat did not stop pressing the lever even if the rat next to it received an electric shock. Ta.

Julen Hernandez-Lallement, lead author of the study and a researcher at NIN, said, ``It seems that rats, like humans, have an aversion to harming others.'' Masu.

'It's surprising that humans and rats use the same brain regions to avoid harming others,' said Valeria Gazzola, one of the study's authors. 'This suggests that the moral motivations that allow us to do so were acquired early in evolution.'