title: Adaptable history biases in human perceptual decisions.
abstract: When making choices under conditions of perceptual uncertainty, past experience can play a vital role. However, it can also lead to biases that worsen decisions. Consistent with previous observations, we found that human choices are influenced by the success or failure of past choices even in a standard two-alternative detection task, where choice history is irrelevant. The typical bias was one that made the subject switch choices after a failure. These choice history biases led to poorer performance and were similar for observers in different countries. They were well captured by a simple logistic regression model that had been previously applied to describe psychophysical performance in mice. Such irrational biases seem at odds with the principles of reinforcement learning, which would predict exquisite adaptability to choice history. We therefore asked whether subjects could adapt their irrational biases following changes in trial order statistics. Adaptability was strong in the direction that confirmed a subject's default biases, but weaker in the opposite direction, so that existing biases could not be eradicated. We conclude that humans can adapt choice history biases, but cannot easily overcome existing biases even if irrational in the current context: adaptation is more sensitive to confirmatory than contradictory statistics.
authors.affiliation: Department of Psychology and Neurosciences Institute, Stanford University, Stanford, CA 94305; Laboratory for Human Systems Neuroscience, RIKEN Brain Science Institute, Wako-shi, Saitama 351-0198, Japan; armana@stanford.edu.
authors.forename: Arman
authors.initials: A
authors.lastname: Abrahamyan
authors.affiliation: UCL Institute of Ophthalmology, University College London, London EC1V 9EL, United Kingdom.
authors.forename: Laura Luz
authors.initials: LL
authors.lastname: Silva
authors.affiliation: UCL Institute of Ophthalmology, University College London, London EC1V 9EL, United Kingdom.
authors.forename: Steven C
authors.initials: SC
authors.lastname: Dakin
authors.affiliation: UCL Institute of Ophthalmology, University College London, London EC1V 9EL, United Kingdom.
authors.forename: Matteo
authors.identifier: 0000-0003-4880-7682
authors.initials: M
authors.lastname: Carandini
authors.affiliation: Department of Psychology and Neurosciences Institute, Stanford University, Stanford, CA 94305; Laboratory for Human Systems Neuroscience, RIKEN Brain Science Institute, Wako-shi, Saitama 351-0198, Japan;
authors.forename: Justin L
authors.initials: JL
authors.lastname: Gardner
mesh_terms: D003657:Decision Making; D005246:Feedback; D006801:Humans; D010465:Perception; D035501:Uncertainty
keywords: bias adaptation; choice bias; choice history; computational modeling; decision making