Dopamine is the brain’s motivational spark, driving us to chase what feels good, say scrolling another reel on social media, and steer clear of what doesn’t, like touching a hot stove. But scientists haven’t fully understood how dopamine helps us learn to avoid bad outcomes — until now.

A new study from Northwestern University shows that dopamine signals in two key brain areas involved in motivation and learning respond differently to negative experiences, helping the brain adapt based on whether a situation is predictable or controllable. 

While previous research has shown that dopamine can respond to negative experiences, this is the first study to track how those signals evolve over time as animals move from novices to experts in avoiding them. 

At the heart of the Amazon researchers are investigating a mysterious parasite which is devastating fish farms around the world.