The Solomon H. Snyder Department of Neuroscience, Brain Science Institute, Kavli Neuroscience Discovery Institute, The Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA.
The Solomon H. Snyder Department of Neuroscience, Brain Science Institute, Kavli Neuroscience Discovery Institute, The Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA.
Curr Biol. 2022 Feb 7;32(3):586-599.e7. doi: 10.1016/j.cub.2021.12.006. Epub 2021 Dec 21.
Regulating how fast to learn is critical for flexible behavior. Learning about the consequences of actions should be slow in stable environments, but accelerate when that environment changes. Recognizing stability and detecting change are difficult in environments with noisy relationships between actions and outcomes. Under these conditions, theories propose that uncertainty can be used to modulate learning rates ("meta-learning"). We show that mice behaving in a dynamic foraging task exhibit choice behavior that varied as a function of two forms of uncertainty estimated from a meta-learning model. The activity of dorsal raphe serotonin neurons tracked both types of uncertainty in the foraging task as well as in a dynamic Pavlovian task. Reversible inhibition of serotonin neurons in the foraging task reproduced changes in learning predicted by a simulated lesion of meta-learning in the model. We thus provide a quantitative link between serotonin neuron activity, learning, and decision making.
调节学习速度对于灵活行为至关重要。在稳定的环境中，对行为后果的学习应该较慢，但当环境发生变化时，学习速度应该加快。在行为与结果之间存在噪声关系的环境中，识别稳定性和检测变化是困难的。在这些条件下，理论提出不确定性可以用来调节学习率（“元学习”）。我们表明，在动态觅食任务中表现行为的老鼠表现出的选择行为随着从元学习模型估计的两种不确定性形式而变化。中缝背核 5-羟色胺神经元的活动在觅食任务中以及在动态巴甫洛夫任务中都跟踪了这两种类型的不确定性。在觅食任务中可逆抑制 5-羟色胺神经元，再现了模型中元学习模拟损伤预测的学习变化。因此，我们提供了 5-羟色胺神经元活动、学习和决策之间的定量联系。
