title: Optimal inference with suboptimal models: addiction and active Bayesian inference.
abstract: 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.
authors.affiliation: The Wellcome Trust Centre for Neuroimaging, UCL, 12 Queen Square, London WC1N 3BG, UK; Institute for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria; Neuroscience Institute, Christian-Doppler-Klinik, Paracelsus Medical University Salzburg, Salzburg, Austria. Electronic address: philipp.schwartenbeck.@sbg.ac.at.
authors.forename: Philipp
authors.initials: P
authors.lastname: Schwartenbeck
authors.affiliation: The Wellcome Trust Centre for Neuroimaging, UCL, 12 Queen Square, London WC1N 3BG, UK.
authors.forename: Thomas H B
authors.initials: TH
authors.lastname: FitzGerald
authors.affiliation: The Wellcome Trust Centre for Neuroimaging, UCL, 12 Queen Square, London WC1N 3BG, UK.
authors.forename: Christoph
authors.initials: C
authors.lastname: Mathys
authors.affiliation: The Wellcome Trust Centre for Neuroimaging, UCL, 12 Queen Square, London WC1N 3BG, UK.
authors.forename: Ray
authors.initials: R
authors.lastname: Dolan
authors.affiliation: Department of Psychiatry and Psychotherapy II, Christian-Doppler Hospital, Paracelsus Medical University, Salzburg, Austria.
authors.forename: Friedrich
authors.initials: F
authors.lastname: Wurst
authors.affiliation: Institute for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria; Neuroscience Institute, Christian-Doppler-Klinik, Paracelsus Medical University Salzburg, Salzburg, Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Kronbichler
authors.affiliation: The Wellcome Trust Centre for Neuroimaging, UCL, 12 Queen Square, London WC1N 3BG, UK.
authors.forename: Karl
authors.initials: K
authors.lastname: Friston
mesh_terms: D001499:Bayes Theorem; D016739:Behavior, Addictive / Q000523:psychology*; D002755:Choice Behavior / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D003198:Computer Simulation; D003657:Decision Making / Q000502:physiology*; D006801:Humans; D008960:Models, Psychological