The neural basis of belief updating and rational decision making
2014, Achtziger, Anja, Alós-Ferrer, Carlos, Hügelschäfer, Sabine, Steinhauser, Marco
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.
Social preferences and self-control
2011, Achtziger, Anja, Alós-Ferrer, Carlos, Wagner, Alexander
We study the interaction of different motives and decision processes in determining behavior in the ultimatum game. We rely on an experimental manipulation called ego depletion which consumes self-control resources, thereby enhancing the influence of default reactions or, in psychological terms, automatic processes. We find that proposers make lower offers under ego depletion, i.e. self-centered monetary concerns are the default mode and not other-regarding considerations (fairness towards others). Responders are more likely to reject low offers under ego depletion, i.e. the affect-influenced reaction to reject unfair offers (reaction to unfairness towards oneself) is more automatic than unconditional monetary concerns.