title: Neuronal Mechanisms of Visual Categorization: An Abstract View on Decision Making.
abstract: Categorization is our ability to flexibly assign sensory stimuli into discrete, behaviorally relevant groupings. Categorical decisions can be used to study decision making more generally by dissociating category identity of stimuli from the actions subjects use to signal their decisions. Here we discuss the evidence for such abstract categorical encoding in the primate brain and consider the relationship with other perceptual decision paradigms. Recent work on visual categorization has examined neuronal activity across a hierarchically organized network of cortical areas in monkeys trained to group visual stimuli into arbitrary categories. This has revealed a transformation of visual-feature encoding in early visual cortical areas into more flexible categorical representations in downstream parietal and prefrontal areas. These neuronal category representations are encoded as abstract internal cognitive states because they are not rigidly linked with either specific sensory stimuli or the actions that the monkeys use to signal their categorical choices.
authors.affiliation: Department of Neurobiology, University of Chicago, Chicago, Illinois 60637; email: dfreedman@uchicago.edu.|The Grossman Institute for Neuroscience, Quantitative Biology, and Human Behavior, University of Chicago, Chicago, Illinois 60637.
authors.forename: David J
authors.initials: DJ
authors.lastname: Freedman
authors.affiliation: Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115; email: jassad@hms.harvard.edu.|Istituto Italiano di Tecnologia, 16163 Genova, Italy.
authors.forename: John A
authors.initials: JA
authors.lastname: Assad
mesh_terms: D000818:Animals; D001519:Behavior / Q000502:physiology; D003071:Cognition / Q000502:physiology*; D003657:Decision Making / Q000502:physiology*; D006801:Humans; D010775:Photic Stimulation / Q000379:methods; D014793:Visual Cortex / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*
keywords: categorization; decision making; learning and memory; parietal cortex; perception; prefrontal cortex; recognition; vision