Cognitive and Computational Neuroscience Laboratory (LNC(2)), Inserm U960, Department of Cognitive Studies, École Normale Supérieure, PSL University, 29 rue d'Ulm, 75005 Paris, France.
Cognitive and Computational Neuroscience Laboratory (LNC(2)), Inserm U960, Department of Cognitive Studies, École Normale Supérieure, PSL University, 29 rue d'Ulm, 75005 Paris, France.
Neuroimage. 2020 Nov 15;222:117253. doi: 10.1016/j.neuroimage.2020.117253. Epub 2020 Aug 13.
The ability to swiftly and accurately respond to others' non-verbal signals, such as their emotional expressions, constitutes one of the building blocks for social adaptation. It is debated whether rapid action tendencies to socio-emotional signals solely depend upon stimulus-evoked pre-decisional motor bias or can also engage goal-directed (decisional) processes that involve the arbitration between action alternatives. Here, we used drift diffusion models (DDMs) of choice and electroencephalography (EEG) to investigate the impact of threat-signaling individuals (angry or fearful) on spontaneous approach-avoidance decisions. Participants choose to avoid angry individuals more often than fearful ones and this effect was stronger for intense expressions. Diffusion models showed that this pattern of choice was accounted for by a process of value-based evidence accumulation, suggesting an active competition between action options. At the brain level, we found that EEG activity preceding movement initiation (200 ms) in a mid-frontal cluster of electrodes - sourced in the orbital and ventromedial frontal cortices - encoded value difference between chosen and unchosen options, thus predicting participant's choices on a trial-by-trial basis. Furthermore, value difference also modulated EEG signal during feedback about the decision. Altogether, the present findings convincingly support the underestimated influence of implicit goal-directed mechanisms in approach-avoidance responses to socio-emotional signals.
快速准确地对他人的非言语信号（如情绪表达）做出反应，是社会适应的基础之一。目前尚存在争议，即社会情感信号的快速行动倾向是否仅仅取决于刺激引发的决策前运动偏差，还是也可以参与涉及行动选择之间仲裁的目标导向（决策）过程。在这里，我们使用选择的漂移扩散模型（DDMs）和脑电图（EEG）来研究威胁信号个体（愤怒或恐惧）对自发接近-回避决策的影响。参与者更频繁地选择回避愤怒的个体，而对于强烈的表情，这种效果更强。扩散模型表明，这种选择模式是由基于价值的证据积累过程解释的，表明行动选择之间存在积极竞争。在大脑水平上，我们发现，在运动起始前 200 毫秒（潜伏期），电极中部额区的 EEG 活动——来源于眶额和腹内侧前额皮质——编码了所选和未选选项之间的价值差异，从而可以逐次预测参与者的选择。此外，价值差异还调节了关于决策的反馈期间的 EEG 信号。总之，这些发现令人信服地支持了在对社会情感信号的接近-回避反应中，隐性目标导向机制被低估的影响。
