title: Variance misperception explains illusions of confidence in simple perceptual decisions.
abstract: Confidence in a perceptual decision is a judgment about the quality of the sensory evidence. The quality of the evidence depends not only on its strength ('signal') but critically on its reliability ('noise'), but the separate contribution of these quantities to the formation of confidence judgments has not been investigated before in the context of perceptual decisions. We studied subjective confidence reports in a multi-element perceptual task where evidence strength and reliability could be manipulated independently. Our results reveal a confidence paradox: confidence is higher for stimuli of lower reliability that are associated with a lower accuracy. We show that the subjects' overconfidence in trials with unreliable evidence is caused by a reduced sensitivity to stimulus variability. Our results bridge between the investigation of miss-attributions of confidence in behavioral economics and the domain of simple perceptual decisions amenable to neuroscience research.
authors.affiliation: Laboratory of Integrative Neuroscience, Physics Department, FCEyN UBA and IFIBA, Conicet, Pabellón 1, Ciudad Universitaria, 1428 Buenos Aires, Argentina; Department of Vision and Cognition, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, The Netherlands; Institute of Biomedical Engineering, Faculty of Engineering, Buenos Aires University, 1063 Buenos Aires, Argentina; Laboratory of Applied Artificial Intelligence, Computer Science Department, FCEyN UBA, Pabellón 1, Ciudad Universitaria, 1428 Buenos Aires, Argentina. Electronic address: ariel.zylberberg@gmail.com.
authors.forename: Ariel
authors.initials: A
authors.lastname: Zylberberg
authors.affiliation: Department of Vision and Cognition, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, The Netherlands; Department of Integrative Neurophysiology, VU University Amsterdam, The Netherlands; Psychiatry Department, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Pieter R
authors.initials: PR
authors.lastname: Roelfsema
authors.affiliation: Laboratory of Integrative Neuroscience, Physics Department, FCEyN UBA and IFIBA, Conicet, Pabellón 1, Ciudad Universitaria, 1428 Buenos Aires, Argentina; Universidad Torcuato Di Tella, Almirante Juan Saenz Valiente 1010, C1428BIJ Buenos Aires, Argentina.
authors.forename: Mariano
authors.initials: M
authors.lastname: Sigman
mesh_terms: D000328:Adult; D003657:Decision Making / Q000502:physiology*; D006801:Humans; D007088:Illusions / Q000502:physiology*; D017603:Signal Detection, Psychological / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*
keywords: Introspection; Metacognition; Perceptual decisions; Sensory reliability; Signal-detection theory