牛津大学Armin Lak课题组在研究中取得进展。他们的论文发现了多巴胺为个人学习轨迹编码深度网络教学信号。相关论文发表在2025年6月11日出版的《细胞》杂志上。
该课题组研究人员在小鼠学习决策任务时纵向测量和控制背纹状体多巴胺信号。小鼠的学习轨迹在策略序列中转换，显示出显著的个体多样性。值得注意的是，这些转变是系统性的；每个主题的早期策略决定了几周后的策略。多巴胺信号反映了每种动物的过渡策略，编码了刺激-选择关联的子集。光遗传操作选择性地更新了这些关联，导致学习效果不同于奖励。一个深度神经网络对异构教学信号进行主题化，每个信号更新一个网络关联权重子集，从而捕获它们的结果。分析模型的不动点说明了学习的多样性和系统性。总之，这项工作提供了对个人长期学习轨迹的生物学和数学原理的见解。
据悉，纹状体多巴胺在微调学习决策中起着重要作用。然而，当从初学者到专家学习时，个体往往表现出不同的学习轨迹，无视其潜在的多巴胺能机制的理解。
附：英文原文
Title: Dopamine encodes deep network teaching signals for individual learning trajectories
Author: Samuel Liebana, Aeron Laffere, Chiara Toschi, Louisa Schilling, Jessica Moretti, Jacek Podlaski, Matthias Fritsche, Peter Zatka-Haas, Yulong Li, Rafal Bogacz, Andrew Saxe, Armin Lak
Issue&Volume: 2025-06-11
Abstract: Striatal dopamine plays fundamental roles in fine-tuning learned decisions. However, when learning from naive to expert, individuals often exhibit diverse learning trajectories, defying understanding of its underlying dopaminergic mechanisms. Here, we longitudinally measure and manipulate dorsal striatal dopamine signals in mice learning a decision task from naive to expert. Mice learning trajectories transitioned through sequences of strategies, showing substantial individual diversity. Remarkably, the transitions were systematic; each mouse’s early strategy determined its strategy weeks later. Dopamine signals reflected strategies each animal transitioned through, encoding a subset of stimulus-choice associations. Optogenetic manipulations selectively updated these associations, leading to learning effects distinct from that of reward. A deep neural network using heterogeneous teaching signals, each updating a subset of network association weights, captured our results. Analyzing the model’s fixed points explained learning diversity and systematicity. Altogether, this work provides insights into the biological and mathematical principles underlying individual long-term learning trajectories.
DOI: 10.1016/j.cell.2025.05.025
Source: https://www.cell.com/cell/abstract/S0092-8674(25)00575-6