By Stephen Beech via SWNS
Mice think just like human babies, according to new research.
The rodents’ “surprisingly strategic” behavior has depended on the understanding of how animals’ brains work, say scientists.
Professor Kishore Kuchibhotla, a neuroscientist who studies learning in humans and animals, wondered why rodents often performed poorly in tests when they knew how to perform well.
With a simple experiment, and by acting as “a little bit of a mouse psychologist,” he and his team figured it out.
Kuchibhotla, of Johns Hopkins University, said: “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.”
He said the findings, published in the journal Current Biology, could lead to identifying the neural basis for devising strategies.
Kuchibhotla’s lab has previously found that animals know a lot more about tasks than they show in tests.
His team had two theories about what could be behind the gap: either the mice were making mistakes because they were stressed, or they were doing something more purposeful: exploring and testing their knowledge.
Kuchibhotla and Ziyi Zhu, a graduate student studying neuroscience, came up with a new experiment to try and work it out.
Mice heard two sounds: for one sound they were supposed to turn a wheel to the left; for the other sound, they’d turn the wheel to the right. When the mice performed correctly they were rewarded.
The research team observed how upon hearing either sound over consecutive trials, the mice would turn the wheel left for a bit, then switch to turning it right, seemingly making mistakes – but actually being purposeful.
Kuchibhotla said: “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.”
Zhu added: “Errors during animal learning are often considered as mistakes.
“Our work brings new insight that not all errors are the same.”
The researchers learned even more about the rodents’ actions by taking the reward out of the equation.
They found that when a mouse performed correctly and wasn’t rewarded, it immediately doubled down on the correct response when retested.
Kuchibhotla said: “If the animal has an internal model of the task, the lack of reward should violate its expectation.
“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.’”
If the animal didn’t have an internal model of the task, he said there would be no expectations to violate and the mice would keep performing poorly.
Kuchibhotla added: “At a very early time in learning the animal has an expectation and when we violate it, it changes its strategy.
“It was surprisingly strategic.”
He says the mouse strategizing is comparable to how non-verbal human babies learn.
He explained that both are highly exploratory and both may test hypotheses in numerous ways.
During the experiments, Kuchibhotla said he became “a little bit of a mouse psychologist” to interpret their behavior.
Like working with a baby before they can talk, he and Zhu had to infer the underlying mental processes from the behavior alone.
Kuchibhotla added: “That’s what was really fun in this project, trying to figure out what the mouse is thinking.
“You have to think about it from the perspective of the animal.”
Now the researchers hope to determine the neural basis for strategic thinking, and how those strategies might compare in different species.
