Motivation plays a crucial role in recovery after stroke. Many rehabilitation programs rely on feedback and rewards to encourage patients to practice movements, but stroke can subtly disrupt the brain systems that process reward. A new study by Yésica E. Martínez and colleagues from the University of Zurich shows that stroke leads to a reorganization of the brain’s reward network during motor learning, altering how different regions communicate when rewards are at stake.
Motivation is largely mediated by the brain’s dopamine‑based reward network, which helps the brain learn from success and stay engaged in goal‑directed behavior. Because stroke rehabilitation often relies on feedback and rewards to motivate practice, the researchers examined how stroke alters communication within this reward network. In the study, 28 people in the subacute phase after stroke and 18 healthy controls performed a wrist‑movement learning task while undergoing functional MRI. Crucially, they received performance‑dependent monetary rewards, a well‑established way to engage reward‑related brain circuits. Instead of analyzing activity in individual brain regions, the researchers focused on functional connectivity, assessing how strongly different regions of the reward network interacted during reward feedback.
The results revealed that stroke leads to a significant reward network reorganization. Compared with healthy controls, stroke patients showed increased connectivity between several reward‑ and motor‑related regions. At the same time, reduced connectivity was observed between key reward hubs involved in assigning value to outcomes. Increased connectivity may reflect compensation; decreased connectivity may impair reward processing and learning. Notably, patients and controls performed similarly on the task and earned comparable rewards, suggesting that these neural changes were not simply due to worse performance or reduced motivation.
The findings support the idea that targeting reward pathways via feedback, incentives, or brain stimulation could contribute to motor recovery after stroke. The study further highlights the need for future research to determine how different patterns of reward network reorganization after stroke – whether compensatory or maladaptive – affect motivation, learning, and recovery over time, and how these networks can be targeted to improve rehabilitation outcomes.
Reference: Martínez YE, Widmer M, Zimmermann J, Schönhammer JG, Luft AR, Jäncke L. Brain reorganization: altered functional connectivity in reward network after stroke. NeuroImage: Clinical. 2025. https://doi.org/10.1016/j.nicl.2025.103914
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