Perspective | Published:

Confidence and certainty: distinct probabilistic quantities for different goals

Nature Neuroscience volume 19, pages 366374 (2016) | Download Citation

Abstract

When facing uncertainty, adaptive behavioral strategies demand that the brain performs probabilistic computations. In this probabilistic framework, the notion of certainty and confidence would appear to be closely related, so much so that it is tempting to conclude that these two concepts are one and the same. We argue that there are computational reasons to distinguish between these two concepts. Specifically, we propose that confidence should be defined as the probability that a decision or a proposition, overt or covert, is correct given the evidence, a critical quantity in complex sequential decisions. We suggest that the term certainty should be reserved to refer to the encoding of all other probability distributions over sensory and cognitive variables. We also discuss strategies for studying the neural codes for confidence and certainty and argue that clear definitions of neural codes are essential to understanding the relative contributions of various cortical areas to decision making.

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Acknowledgements

The authors would like to thank Z. Mainen, R. Kiani, P. Latham, P. Dayan, J. Sanders and B. Hangya for stimulating discussions about the definition and utility of the concept of confidence and A. Urai and P. Masset for comments on the manuscript. This work was supported by grants from the Simons Global Brain Initiative (A.P.) and the US National Institutes of Health (R01MH097061) to A.K.

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Affiliations

  1. Department of Basic Neuroscience, University of Geneva, Geneva, Switzerland.

    • Alexandre Pouget
    •  & Jan Drugowitsch
  2. Department of Brain and Cognitive Sciences, University of Rochester, Rochester, New York, USA.

    • Alexandre Pouget
  3. Gatsby Computational Neuroscience Unit, London, UK.

    • Alexandre Pouget
  4. Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA.

    • Adam Kepecs

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The authors declare no competing financial interests.

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Correspondence to Alexandre Pouget.

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DOI

https://doi.org/10.1038/nn.4240

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