title: The neural basis of belief updating and rational decision making.
abstract: Rational decision making under uncertainty requires forming beliefs that integrate prior and new information through Bayes' rule. Human decision makers typically deviate from Bayesian updating by either overweighting the prior (conservatism) or overweighting new information (e.g. the representativeness heuristic). We investigated these deviations through measurements of electrocortical activity in the human brain during incentivized probability-updating tasks and found evidence of extremely early commitment to boundedly rational heuristics. Participants who overweight new information display a lower sensibility to conflict detection, captured by an event-related potential (the N2) observed around 260 ms after the presentation of new information. Conservative decision makers (who overweight prior probabilities) make up their mind before new information is presented, as indicated by the lateralized readiness potential in the brain. That is, they do not inhibit the processing of new information but rather immediately rely on the prior for making a decision.
authors.affiliation: Department of Economics Box 150, University of Konstanz, 78457 Konstanz, Germany. carlos.alos-ferrer@uni-konstanz.de.
authors.forename: Anja
authors.initials: A
authors.lastname: Achtziger
authors.forename: Carlos
authors.initials: C
authors.lastname: Alós-Ferrer
authors.forename: Sabine
authors.initials: S
authors.lastname: Hügelschäfer
authors.forename: Marco
authors.initials: M
authors.lastname: Steinhauser
mesh_terms: D000328:Adult; D001499:Bayes Theorem; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D003265:Contingent Negative Variation / Q000502:physiology*; D003469:Culture; D003657:Decision Making / Q000502:physiology*; D004569:Electroencephalography; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D012044:Regression Analysis; D055815:Young Adult