You Used to Think Like a Mouse, Brain Study Reveals

A new brain study has revealed that you may have had similar thought processes to a mouse when you were a baby.

Johns Hopkins University neuroscientist Kishore Kuchibhotla has worked with mice for a long time and previously discovered that the rodents understand a lot more about tasks then they let on.

For this reason, he and neuroscience graduate student Ziyi Zhu set out to understand why they perform poorly in certain scenarios, when they clearly know how to perform well. The findings are published in the journal Current Biology.

The scientists believed that the mice were either performing poorly due to anxiety or were actively exploring the scenario and trying to test their own knowledge.

To find out which one it was, researchers initiated an experiment in which mice heard two sounds. For one sound, the mice were supposed to turn the wheel to the left. For the other, they were supposed to turn it to the right.

Mice that performed the right actions were rewarded with a treat.

The study found that in several circumstances, the mice would turn the wheel in both directions, after hearing one of the sounds. This suggested to the researchers that although the mice were performing the wrong action, they were being purposeful in their actions, the study reports.

"It appears that a big part of this gap between knowledge and performance is that the animal is engaging in a form of exploration—what the animal is doing is very clever. It's hard to say animals are making hypotheses, but our view is that animals, like humans, can make hypotheses and they can test them and may use higher cognitive processes to do it," Kuchibhotla said in a statement.

"We find that when the animal is exploring, they engage in a really simple strategy, which is, 'I'm going to go left for a while, figure things out, and then I'm going to switch and go right for a while. Mice are more strategic than some might believe."

In fact, this behavior is remarkably similar to how human babies, who can't yet talk, learn certain tasks, the study reported.

The scientists also took the reward out of the equation for some tests, to see how the mice would perform. They found that after a mouse performed the correct action and did not gain a reward, it proceeded to double down on performing the right action in the next test.

"If the animal has an internal model of the task, the lack of reward should violate its expectation," Kuchibhotla said. "And if that's the case, it should affect the behavior on subsequent trials. And that's exactly what we found. On subsequent trials the animal just does a lot better. The animal is like, 'Hey, I was expecting to be rewarded, I wasn't, so let me test my knowledge, let me use the knowledge I have and see if it's correct.'"

Zhu said that errors performed by animals during tests are often seen as mistakes, but these findings bring "new insight that not all errors are the same."

The findings should deepen scientists' understanding of how animal brains work and the capacity they have for learning tasks.

"That's what was really fun in this project, trying to figure out what the mouse is thinking," Kuchibhotla said. "You have to think about it from the perspective of the animal."

Do you have a tip on a science story that Newsweek should be covering? Do you have a question about atmospheric rivers? Let us know via science@newsweek.com.