Mice Strategize: Clever Rodents Test Hypotheses

Summary: Mice are capable of strategic thinking and hypothesis testing, challenging previous perceptions of their cognitive abilities.

By observing mice’s responses to auditory cues linked to specific actions, the researchers discovered that what appeared as mistakes were actually deliberate exploratory actions. This approach allows the mice to test and adjust their strategies, revealing a level of cognitive processing similar to hypothesis testing in humans.

The findings could reshape our understanding of animal cognition and have implications for studying the neural bases of strategizing.

Key Facts:

  1. Strategic Exploration: Mice demonstrated strategic behavior by alternating their responses in a controlled setting, suggesting they engage in a form of hypothesis testing.
  2. Response to Reward Violations: Mice adjusted their behavior significantly when their expectations of a reward were not met, indicating they possess an internal model of the task.
  3. Implications for Cognitive Science: The study provides evidence that mice can use higher cognitive processes, which could lead to new insights into the neural mechanisms underlying strategic thinking.

Source: Johns Hopkins University

Are mice clever enough to be strategic?

Kishore Kuchibhotla, a Johns Hopkins University neuroscientist who studies learning in humans and animals, and who has long worked with mice, 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.

This shows mice.
This mouse strategizing is comparable to how nonverbal human babies learn. Credit: Neuroscience News

“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,” he said.

“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.”

The work, which deepens our understanding of animal cognition, and could lead to identifying the neural basis for strategizing, published today in Current Biology.

Kuchibhotla’s lab previously found that animals know a lot more about tasks than they demonstrate in tests. The team had two theories about what could be behind this gap. Either the mice were making mistakes because they were stressed, or they were doing something more purposeful: exploring and testing their knowledge.

To figure it out Kuchibhotla and Ziyi Zhu, a graduate student studying neuroscience, came up with a new experiment.

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 researchers 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.

“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,’” Kuchibhotla said.

“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 team learned even more about the rodents’ actions by taking the reward out of the equation.

When a mouse performed correctly and wasn’t rewarded, it immediately doubled down on the correct response when retested.

“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,” Kuchibhotla said.

“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, there would be no expectations to violate and the mice would keep performing poorly.

“At a very early time in learning the animal has an expectation and when we violate it, it changes its strategy,” Kuchibhotla said. “It was surprisingly strategic.”

This mouse strategizing is comparable to how nonverbal human babies learn. Both are highly exploratory and both may test hypotheses in various ways, Kuchibhotla said.

During the experiments Kuchibhotla said he became “a little bit of a mouse psychologist” to interpret their behavior. Like working with a nonverbal infant, he and Zhu had to infer the underlying mental processes from the behavior alone.

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

Next the team hopes to determine the neural basis for strategic thinking, and how those strategies might compare across different animals.

About this animal cognition research news

Author: Jill Rosen
Source: Johns Hopkins University
Contact: Jill Rosen – Johns Hopkins University
Image: The image is credited to Neuroscience News

Original Research: Closed access.
Performance errors during rodent learning reflect a dynamic choice strategy” by Kishore Kuchibhotla et al. Current Biology


Performance errors during rodent learning reflect a dynamic choice strategy


  • Errors while learning a two-choice task are dominated by intentional strategies
  • Strategies manifest as a dynamic choice bias, testing one option or another in bouts
  • Mice exhibit sensitivity to violations of expected reward during biased epochs
  • Violating expectations leads to an abrupt shift in strategy


Humans, even as infants, use cognitive strategies, such as exploration and hypothesis testing, to learn about causal interactions in the environment. In animal learning studies, however, it is challenging to disentangle higher-order behavioral strategies from errors arising from imperfect task knowledge or inherent biases.

Here, we trained head-fixed mice on a wheel-based auditory two-choice task and exploited the intra- and inter-animal variability to understand the drivers of errors during learning. During learning, performance errors are dominated by a choice bias, which, despite appearing maladaptive, reflects a dynamic strategy.

Early in learning, mice develop an internal model of the task contingencies such that violating their expectation of reward on correct trials (by using short blocks of non-rewarded “probe” trials) leads to an abrupt shift in strategy.

During the probe block, mice behave more accurately with less bias, thereby using their learned stimulus-action knowledge to test whether the outcome contingencies have changed. Despite having this knowledge, mice continued to exhibit a strong choice bias during reinforced trials.

This choice bias operates on a timescale of tens to hundreds of trials with a dynamic structure, shifting between left, right, and unbiased epochs. Biased epochs also coincided with faster motor kinematics.

Although bias decreased across learning, expert mice continued to exhibit short bouts of biased choices interspersed with longer bouts of unbiased choices and higher performance.

These findings collectively suggest that during learning, rodents actively probe their environment in a structured manner to refine their decision-making and maintain long-term flexibility.

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