Neuroscientists have uncovered a fascinating piece of the puzzle behind what makes us truly intelligent. While machines excel at repetitive tasks, humans and animals amaze with their ability to adapt, imagine, and generalize. What in the brain allows for this flexible thinking? A recent study in mice gives us clues by identifying specific brain cells responsible for tracking progress in complex behaviors—not just physical locations.

For decades, it has been known that certain brain cells, like place cells and grid cells, help animals navigate physical space. These cells create mental maps of the environment, guiding an animal or person through streets, rooms, or mazes. But what about navigating through a sequence of actions, such as cooking a new recipe or solving a fresh problem?

Researchers trained mice to perform a task in which they moved through a series of four goal locations to receive water rewards. The order of goals repeated in a loop, but to challenge them, the locations were moved. The mice instantly adjusted, understanding the sequence even in completely new situations. This wasn’t memory playing tricks; the mice were generalizing the structure of the task.

Imagine you’re walking to work when the unspeakable occurs: Your favorite coffee shop—where you stop every day—is closed. You groggily navigate to a newly opened coffee shop a couple blocks away, which, you’re pleased to discover, actually makes quite a good morning brew. Soon, you find yourself looking forward to stopping at the new location instead of the old one.

That switch probably alters more than just your morning routine. Each time you visit that new coffee shop, the experience likely strengthens a neural map marking the positions of rewarding experiences—a map that can guide you back to those experiences even from miles away.

While the existence of a reward map is familiar from previous work, Wu Tsai Neuro researchers working with mice were surprised to find that the map persists even when mice move many meters away from a treat, and that it updates almost immediately when the location of the treat changes.

Toothed whales use sound to find their way around, detect objects, and catch fish. They can investigate their environment by making clicking sounds, and then decoding the “echoic return signal” created when the clicking sounds bounce off objects and return to their ears. This “biosonar,” called echolocation, is rare in the animal kingdom.

Now, a new study by researchers at the Woods Hole Oceanographic Institution, New College of Florida, UC Berkeley, and Oxford University, and published in PLOS One, brings us closer to understanding how dolphin brains have evolved to support echolocation.

The research team applied new techniques for mapping networks in the excised brains of dead, stranded cetaceans to examine and compare the auditory pathways in echolocating dolphins and a non-echolocating baleen whale called a sei whale. A partnership with the International Fund for Animal Welfare (IFAW) and others is critical to advancing this work.

Populations of dopamine neurons don’t simply signal reward prediction errors—they encode rich maps of possible future outcomes, including when and how much a reward might be.