Achtziger Anja, Alós-Ferrer Carlos, Hügelschäfer Sabine, Steinhauser Marco
Department of Economics Box 150, University of Konstanz, 78457 Konstanz, Germany.
Soc Cogn Affect Neurosci. 2014 Jan;9(1):55-62. doi: 10.1093/scan/nss099. Epub 2012 Sep 5.
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.
在不确定性下进行理性决策需要通过贝叶斯法则形成整合先验信息和新信息的信念。人类决策者通常偏离贝叶斯更新，要么过度重视先验信息（保守主义），要么过度重视新信息（例如代表性启发法）。我们通过在激励性概率更新任务中测量人类大脑的脑电活动来研究这些偏差，并发现了对有限理性启发法的极早期承诺的证据。过度重视新信息的参与者对冲突检测的敏感性较低，这通过在新信息呈现后约260毫秒观察到的一种事件相关电位（N2）来体现。保守的决策者（过度重视先验概率）在新信息呈现之前就已下定决心，大脑中的侧化准备电位表明了这一点。也就是说，他们不会抑制对新信息的处理，而是立即依赖先验信息来做出决策。
