• Open Access

A common mechanism for adaptive scaling of reward and novelty

Authors

  • Nico Bunzeck,

    Corresponding author
    1. Institute of Cognitive Neuroscience, University College London, London WC1N 3AR, United Kingdom
    • Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London WC1N 3AR, United Kingdom
    Search for more papers by this author
  • Peter Dayan,

    1. Gatsby Computational Neuroscience Unit, London WC1N 3AR, United Kingdom
    Search for more papers by this author
  • Raymond J. Dolan,

    1. Wellcome Department of Imaging Neuroscience, London WC1N 3BG, United Kingdom
    Search for more papers by this author
  • Emrah Duzel

    1. Institute of Cognitive Neuroscience, University College London, London WC1N 3AR, United Kingdom
    2. Institute of Cognitive Neurology and Dementia Research, Otto von Guericke University, 39120 Magdeburg, Germany
    3. German Centre for Neurodegenerative Diseases, Otto-von-Guericke University Magdeburg, 39120 Magdeburg, Germany
    Search for more papers by this author

Abstract

Declarative memory is remarkably adaptive in the way it maintains sensitivity to relative novelty in both unknown and highly familiar environments. However, the neural mechanisms underlying this contextual adaptation are poorly understood. On the basis of emerging links between novelty processing and reinforcement learning mechanisms, we hypothesized that responses to novelty will be adaptively scaled according to expected contextual probabilities of new and familiar events, in the same way that responses to prediction errors for rewards are scaled according to their expected range. Using functional magnetic resonance imaging in humans, we show that the influence of novelty and reward on memory formation in an incidental memory task is adaptively scaled and furthermore that the BOLD signal in orbital prefrontal and medial temporal cortices exhibits concomitant scaled adaptive coding. These findings demonstrate a new mechanism for adjusting gain and sensitivity in declarative memory in accordance with contextual probabilities and expectancies of future events. Hum Brain Mapp, 2010. © 2010 Wiley-Liss, Inc.

Ancillary