The current study used event-related potentials (ERPs) to examine the ability of task demand in modulating the effect of reward association on the processing of emotional faces. In the learning phase, a high or low reward probability was paired with male or female facial photos of angry, happy, or neutral expressions. Then, in the test phase, task demand was manipulated by asking participants to discriminate the emotionality or the gender of the pre-learned face with no reward at stake. The ERP results in the test phase revealed that the fronto-central N1 (60–100 ms) and the VPP (160–210 ms) components were sensitive to the interaction between reward and emotion, in that the differences between the mean amplitudes for high- and low-reward conditions were significantly larger in the neutral face and angry face conditions than in the happy face condition. Moreover, reward association and task demand showed a significant interaction over the right hemisphere for the N170 component (140–180 ms), with amplitude difference between high- and low-reward conditions being larger in the emotion task than that in the gender task. The later N2pc component exhibited an interaction between task demand and emotionality, in that happy faces elicited larger N2pc difference waves than angry and neutral faces did in the emotion task, but neutral faces elicited larger N2pc difference waves than angry faces did in the gender task. The N2pc effect aligned with behavioral performance. These results suggest that reward association acts as an ‘emotional tagging’ to imbue neutral or angry faces with motivational significance at early time windows. Task demand functions in a top-down way to modulate the deployment of attentional resources at the later attentional selection stage, but does not affect the early automatic processing of either emotion or reward association.

当前的研究使用事件相关电位（ERP）来检查任务需求调节奖励关联对情绪面孔处理的影响的能力。在学习阶段，高或低的奖励概率与愤怒、快乐或中性表情的男性或女性面部照片配对。然后，在测试阶段，通过要求参与者区分预先学习的面孔的情绪或性别而没有奖励来操纵任务需求。测试阶段的 ERP 结果显示，额中央 N1（60-100 ms）和 VPP（160-210 ms）组件对奖励和情绪之间的相互作用敏感，因为高的平均振幅之间的差异- 中性面部和愤怒面部条件下的低奖励条件明显大于快乐面部条件下的低奖励条件。此外，奖励关联和任务需求在 N170 部分（140-180 ms）的右半球表现出显着的相互作用，情绪任务中高奖励条件和低奖励条件之间的幅度差异大于性别任务中的幅度差异。后来的N2pc成分表现出任务需求和情绪之间的相互作用，在情感任务中，快乐的面孔比愤怒和中性的面孔引发更大的N2pc差异波，但在性别任务中，中性的面孔比愤怒的面孔引发更大的N2pc差异波。 N2pc 效应与行为表现一致。这些结果表明，奖励关联充当“情绪标签”，在早期时间窗口向中性或愤怒的面孔注入激励意义。任务需求以自上而下的方式发挥作用，调节后期注意力选择阶段注意力资源的部署，但不影响情感或奖励关联的早期自动处理。