In simple instrumental-learning tasks, humans learn to seek gains and to avoid losses equally well. Yet, two effects of valence are observed. First, decisions in loss-contexts are slower. Second, loss contexts decrease individuals’ confidence in their choices. Whether these two effects are two manifestations of a single mechanism or whether they can be partially dissociated is unknown. Across six experiments, we attempted to disrupt the valence-induced motor bias effects by manipulating the mapping between decisions and actions and imposing constraints on response times (RTs). Our goal was to assess the presence of the valence-induced confidence bias in the absence of the RT bias. We observed both motor and confidence biases despite our disruption attempts, establishing that the effects of valence on motor and metacognitive responses are very robust and replicable. Nonetheless, within- and between-individual inferences reveal that the confidence bias resists the disruption of the RT bias. Therefore, although concomitant in most cases, valence-induced motor and confidence biases seem to be partly dissociable. These results highlight new important mechanistic constraints that should be incorporated in learning models to jointly explain choice, reaction times and confidence.

在简单的工具学习任务中，人类学会同样好地寻求收益和避免损失。然而，观察到了两种价态效应。首先，损失上下文中的决策较慢。其次，损失情境会降低个人对其选择的信心。这两种效应是单一机制的两种表现还是可以部分分离尚不清楚。在六个实验中，我们试图通过操纵决策和行动之间的映射并对响应时间 (RT) 施加约束来破坏价引起的运动偏差效应。我们的目标是在没有 RT 偏差的情况下评估价诱导的置信偏差的存在。尽管我们进行了破坏尝试，但我们还是观察到了运动偏差和信心偏差，确定效价对运动和元认知反应的影响非常强大且可复制。尽管如此，个体内部和个体之间的推论表明，置信偏差抵抗了 RT 偏差的破坏。因此，尽管在大多数情况下伴随着价差引起的运动和置信偏差似乎是部分可分离的。这些结果突出了新的重要机械约束，应纳入学习模型以共同解释选择、反应时间和信心。