Optimal inference with suboptimal models: Addiction and active Bayesian inference

Philipp Schwartenbeck (Lead Author), Thomas H B FitzGerald, Christoph Mathys, Ray Dolan, Friedrich Wurst, Martin Kronbichler, Karl Friston

Research output: Contribution to journalArticlepeer-review

78 Citations (Scopus)
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When casting behaviour as active (Bayesian) inference, optimal inference is defined with respect to an agent's beliefs - based on its generative model of the world. This contrasts with normative accounts of choice behaviour, in which optimal actions are considered in relation to the true structure of the environment - as opposed to the agent's beliefs about worldly states (or the task). This distinction shifts an understanding of suboptimal or pathological behaviour away from aberrant inference as such, to understanding the prior beliefs of a subject that cause them to behave less 'optimally' than our prior beliefs suggest they should behave. Put simply, suboptimal or pathological behaviour does not speak against understanding behaviour in terms of (Bayes optimal) inference, but rather calls for a more refined understanding of the subject's generative model upon which their (optimal) Bayesian inference is based. Here, we discuss this fundamental distinction and its implications for understanding optimality, bounded rationality and pathological (choice) behaviour. We illustrate our argument using addictive choice behaviour in a recently described 'limited offer' task. Our simulations of pathological choices and addictive behaviour also generate some clear hypotheses, which we hope to pursue in ongoing empirical work.

Original languageEnglish
Pages (from-to)109-117
Number of pages9
JournalMedical Hypotheses
Issue number2
Early online date15 Dec 2014
Publication statusPublished - Feb 2015


  • Bayes Theorem
  • Addictive Behavior
  • Choice Behavior
  • Cognition
  • Computer Simulation
  • Decision Making
  • Humans
  • Psychological Models

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