Order matters: How covert value updating during sequential option sampling shapes economic preference.

Chen Hu,Philippe Domenech,Mathias Pessiglione

doi:10.1371/journal.pcbi.1007920

Abstract

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.

Highlights

In everyday modern life, people often make choices between multiple options they can browse through, for instance when shopping for groceries, on the internet or at the supermarket
Our study provides a mechanistic understanding of how the option sampling process shapes economic preference, which should be integrated into decision theory
Sampling options is a sequential process that unfolds across time, breaking equity between options by assigning them a serial position

Summary

Introduction

People often make choices between multiple options they can browse through, for instance when shopping for groceries, on the internet or at the supermarket. Sampling options is a sequential process that unfolds across time, breaking equity between options by assigning them a serial position. This sequential allocation of attention is typically neglected in standard decision theory [1,2,3], for which economic choice is construed as the selection of the option maximizing expected utility. According to standard decision theory, the way information about alternative options is collected, in particular their position in the sampling sequence, should not have an impact on the eventual choice. On the contrary, that option sampling is not just passive information gathering, but an active process that covertly updates the utility function on which the eventual choice is based

Objectives

Results

Discussion

Conclusion