Catecholaminergic regulation of learning rate in a dynamic environment

Adaptive behavior in a changing world requires flexibly adapting one’s rate of learning to the rate of environmental change. Recent studies have examined the computational mechanisms by which various environmental factors determine the impact of new outcomes on existing beliefs (i.e., the ‘learning rate’). However, the brain mechanisms, and in particular the neuromodulators, involved in this process are still largely unknown. The brain-wide neurophysiological effects of the catecholamines norepinephrine and dopamine on stimulus-evoked cortical responses suggest that the catecholamine systems are well positioned to regulate learning about environmental change, but more direct evidence for a role of this system is scant. Here, we report evidence from a study employing pharmacology, scalp electrophysiology and computational modeling (N = 32) that suggests an important role for catecholamines in learning rate regulation. We found that the P3 component of the EEG—an electrophysiological inde...

在动态变化的环境中，适应性行为需要个体灵活调节自身的学习速率，以契合环境变化的节奏。既往研究已围绕多种环境因素决定新结果对既有信念的影响的计算机制展开探索，即学习率（learning rate）。然而，该过程所涉及的脑机制，尤其是神经调质（neuromodulators），目前仍未被充分阐明。儿茶酚胺（catecholamines）类递质去甲肾上腺素（norepinephrine）与多巴胺（dopamine）对刺激诱发性皮层反应的全脑神经生理效应提示，儿茶酚胺系统具备调控环境变化相关学习的理想条件，但目前直接证实该系统发挥作用的证据仍较为匮乏。本研究采用药理学、头皮脑电生理学（scalp electrophysiology）与计算建模（computational modeling）手段开展实验（被试量N=32），所得实验证据表明，儿茶酚胺系统在学习率调控中扮演着重要角色。我们发现，脑电图（electroencephalogram, EEG）的P3成分作为一种电生理[原文表述未完整]