Fouragnan Elsa, Retzler Chris, Mullinger Karen, Philiastides Marios G
Institute of Neuroscience &Psychology, University of Glasgow, 58 Hillhead Street, Glasgow G12 8QB, UK.
Department of Behavioural &Social Sciences, University of Huddersfield, Huddersfield HD1 3DH, UK.
Nat Commun. 2015 Sep 8;6:8107. doi: 10.1038/ncomms9107.
Avoiding repeated mistakes and learning to reinforce rewarding decisions is critical for human survival and adaptive actions. Yet, the neural underpinnings of the value systems that encode different decision-outcomes remain elusive. Here coupling single-trial electroencephalography with simultaneously acquired functional magnetic resonance imaging, we uncover the spatiotemporal dynamics of two separate but interacting value systems encoding decision-outcomes. Consistent with a role in regulating alertness and switching behaviours, an early system is activated only by negative outcomes and engages arousal-related and motor-preparatory brain structures. Consistent with a role in reward-based learning, a later system differentially suppresses or activates regions of the human reward network in response to negative and positive outcomes, respectively. Following negative outcomes, the early system interacts and downregulates the late system, through a thalamic interaction with the ventral striatum. Critically, the strength of this coupling predicts participants' switching behaviour and avoidance learning, directly implicating the thalamostriatal pathway in reward-based learning.
避免重复犯错并学会强化有益的决策对于人类生存和适应性行为至关重要。然而，编码不同决策结果的价值系统的神经基础仍然难以捉摸。在这里，我们将单试次脑电图与同时采集的功能磁共振成像相结合，揭示了两个独立但相互作用的编码决策结果的价值系统的时空动态。与调节警觉性和转换行为的作用一致，一个早期系统仅由负面结果激活，并涉及与唤醒相关和运动准备的脑结构。与基于奖励的学习作用一致，一个后期系统分别响应负面和正面结果，差异性地抑制或激活人类奖励网络的区域。在负面结果之后，早期系统通过与腹侧纹状体的丘脑相互作用，与后期系统相互作用并下调后期系统。至关重要的是，这种耦合的强度预测了参与者的转换行为和回避学习，直接表明丘脑纹状体通路在基于奖励的学习中的作用。
