A Boston University-led research team has discovered a dopamine signal in the brain that helps determine whether you are moving toward or away from a goal potentially shedding new light on how the brain uses visual information to guide behavior.
The study recently published in Nature examined behavior in mice to show that when they encounter visual cues, dopamine in the striatum located in the basal ganglia, encodes “trajectory errors” or signals that indicate whether their current direction and speed are carrying it toward or away from its goal. These “guidance signals” operate independently from dopamine’s classic reward value responses and arise from different sensory and motor inputs.
The findings offer insight into how the brain uses environmental cues to steer behavior and could inform the development of more targeted therapies for conditions involving dopamine dysfunction, including Parkinson’s disease, addiction, OCD, and ADHD.
“This discovery reveals that dopamine isn’t just about how valuable something is,” said Mark Howe, Boston University College of Arts & Sciences assistant professor of psychological and brain sciences. “It’s also about whether you’re headed the right way. It’s a guidance signal, one that tells the brain to keep going or make a correction.”
A New View of Dopamine’s Role
For decades, dopamine has been widely understood as the brain’s “reward” chemical, firing when encountering cues associated with something positive. But this new research shows that visual cues also trigger a second, distinct dopamine signal, one that increases when you move toward a goal and decreases when you move away.
This trajectory error signal even scales with movement speed, making it ideal for real time course correction, like how humans might use familiar signs or landmarks while driving home.
Seeing the Brain in New Detail
The team developed a new method that allowed them to measure the dopamine signals optically across many regions throughout the entire striatum.
By mapping these signals, the researchers found the value and trajectory error signals appear in overlapping, but orthogonal spatial gradients within the striatum, and that they also occur at different moments in time. Together, this separation allows the brain to keep the two messages distinct: one for motivation, one for guidance.
Future Work
Howe and his collaborators are now working to manipulate these signals in specific ways to probe the causal impacts on learning and online control of decisions. They are also examining how the signals influence downstream components of the circuit.
“Dopamine is just the input to the striatum,” said Howe, who is also affiliated with Boston University Rajen Kilachand Center for Integrated Life Sciences & Engineering. “We want to understand how these signals shape the activity of downstream circuits to ultimately regulate behavior”
The team is also investigating broader questions: How do these signals translate into changes in movement? Are they essential for learning, online decision-making, or both? These remain key avenues for future research.
This work was supported by a Klingenstein-Simons Foundation fellowship, Whitehall Foundation Fellowship, National Institute of Mental Health and the NIH Jointly Sponsored Predoctoral Training Program in the Neurosciences award.
Complete information on authors, funders, methodology, limitations, and conflicts of interest is available in the published paper.
Nature
Randomized controlled/clinical trial
Animals
Striatum-wide dopamine encodes trajectory errors separated from value
11-Feb-2026
The authors declare no competing interests