近日，英国牛津大学Mark E. Walton等研究人员合作揭示与多巴胺无关的奖励对选择的影响。相关论文于2024年1月12日在线发表在《自然—神经科学》杂志上。

研究人员利用小鼠的两步任务表明，多巴胺利用从任务结构知识中推断出的价值信息以及奖励率和运动信息报告奖赏预测误差（RPE）。然而，尽管奖励对选择和多巴胺活动有很大影响，但在试验结果时激活或抑制多巴胺神经元都不会影响未来的选择。

这些数据被一个神经网络模型所重现，在该模型中，大脑皮层通过预测观察结果来学习跟踪隐藏的任务状态，而基底神经节则通过RPE来学习价值和行动。这表明，奖励对选择的影响可能来自于它们所传达的与多巴胺无关的世界状态相关信息，而不是它们所产生的多巴胺能RPE。

据介绍，多巴胺通过更新价值估计的RPE信号与适应行为有关。还有越来越多的证据表明，结构化环境中的动物可以利用推理过程来促进行为的灵活性。然而，目前还不清楚应该如何整合这两种奖励引导决策的说法。

附：英文原文

Title: Dopamine-independent effect of rewards on choices through hidden-state inference

Author: Blanco-Pozo, Marta, Akam, Thomas, Walton, Mark E.

Issue&Volume: 2024-01-12

Abstract: Dopamine is implicated in adaptive behavior through reward prediction error (RPE) signals that update value estimates. There is also accumulating evidence that animals in structured environments can use inference processes to facilitate behavioral flexibility. However, it is unclear how these two accounts of reward-guided decision-making should be integrated. Using a two-step task for mice, we show that dopamine reports RPEs using value information inferred from task structure knowledge, alongside information about reward rate and movement. Nonetheless, although rewards strongly influenced choices and dopamine activity, neither activating nor inhibiting dopamine neurons at trial outcome affected future choice. These data were recapitulated by a neural network model where cortex learned to track hidden task states by predicting observations, while basal ganglia learned values and actions via RPEs. This shows that the influence of rewards on choices can stem from dopamine-independent information they convey about the world’s state, not the dopaminergic RPEs they produce.

DOI: 10.1038/s41593-023-01542-x

Source: https://www.nature.com/articles/s41593-023-01542-x