Motivation, Brain & Behavior (MBB) team, Paris Brain Institute, Pitié-Salpêtrière Hospital, Paris, France.
Inserm Unit 1127, CNRS Unit 7225, Sorbonne Université, Paris, France.
PLoS Comput Biol. 2020 Aug 11;16(8):e1007920. doi: 10.1371/journal.pcbi.1007920. eCollection 2020 Aug.
Standard neuroeconomic decision theory assumes that choice is based on a value comparison process, independent from how information about alternative options is collected. Here, we investigate the opposite intuition that preferences are dynamically shaped as options are sampled, through iterative covert pairwise comparisons. Our model builds on two lines of research, one suggesting that a natural frame of comparison for the brain is between default and alternative options, the other suggesting that comparisons spread preferences between options. We therefore assumed that during sequential option sampling, people would 1) covertly compare every new alternative to the current best and 2) update their values such that the winning (losing) option receives a positive (negative) bonus. We confronted this "covert pairwise comparison" model to models derived from standard decision theory and from known memory effects. Our model provided the best account of human choice behavior in a novel task where participants (n = 92 in total) had to browse through a sequence of items (food, music or movie) of variable length and ultimately select their favorite option. Consistently, the order of option presentation, which was manipulated by design, had a significant influence on the eventual choice: the best option was more likely to be chosen when it came earlier in the sequence, because it won more covert comparisons (hence a greater total bonus). Our study provides a mechanistic understanding of how the option sampling process shapes economic preference, which should be integrated into decision theory.
标准神经经济学决策理论假设选择是基于价值比较过程的，与如何收集替代选项的信息无关。在这里，我们研究了相反的直觉，即偏好是通过迭代的隐蔽成对比较随着选项的采样而动态形成的。我们的模型基于两条研究线索，一条是默认选项和替代选项之间的比较是大脑的自然比较框架，另一条是比较会在选项之间传播偏好。因此，我们假设在顺序选项采样过程中，人们会 1）对每个新的替代选项与当前最佳选项进行隐蔽比较，2）更新他们的价值，以使获胜（输）选项获得正（负）奖励。我们将这种“隐蔽成对比较”模型与标准决策理论和已知记忆效应的模型进行了对比。我们的模型在一项新颖的任务中对人类选择行为提供了最佳解释，在该任务中，参与者（总共 92 人）必须浏览一系列可变长度的项目（食物、音乐或电影），并最终选择他们最喜欢的选项。一致的是，选项呈现的顺序通过设计进行了操纵，对最终的选择有显著影响：当最佳选项更早出现在序列中时，它更有可能被选中，因为它赢得了更多的隐蔽比较（因此获得了更大的总奖励）。我们的研究提供了一种对选项采样过程如何塑造经济偏好的机制理解，这应该被纳入决策理论。
