Feedback optimizes neural coding and perception of natural stimuli

  1. Chengjie G Huang
  2. Michael G Metzen
  3. Maurice J Chacron  Is a corresponding author
  1. McGill University, Canada


Growing evidence suggests that sensory neurons achieve optimal encoding by matching their tuning properties to the natural stimulus statistics. However, the underlying mechanisms remain unclear. Here we demonstrate that feedback pathways from higher brain areas mediate optimized encoding of naturalistic stimuli via temporal whitening in the weakly electric fish Apteronotus leptorhynchus. While one source of direct feedback uniformly enhances neural responses, a separate source of indirect feedback selectively attenuates responses to low frequencies, thus creating a high-pass neural tuning curve that opposes the decaying spectral power of natural stimuli. Additionally, we recorded from two populations of higher brain neurons responsible for the direct and indirect descending inputs. While one population displayed broadband tuning, the other displayed high-pass tuning and thus performed temporal whitening. Hence, our results demonstrate a novel function for descending input in optimizing neural responses to sensory input through temporal whitening that is likely to be conserved across systems and species.

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Author details

  1. Chengjie G Huang

    Department of Physiology, McGill University, Montreal, Canada
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-7491-6060
  2. Michael G Metzen

    Department of Physiology, McGill University, Montreal, Canada
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-2365-4192
  3. Maurice J Chacron

    Department of Physiology, McGill University, Montreal, Canada
    For correspondence
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-3032-452X


Canadian Institutes of Health Research

  • Maurice J Chacron

Fonds de Recherche du Québec - Nature et Technologies

  • Maurice J Chacron

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.


Animal experimentation: All procedures were approved by McGill University's animal care committee and were performed in accordance to the guidelines set out by the Canadian Council of Animal Care. Protocol 5285.

Reviewing Editor

  1. Catherine Emily Carr, University of Maryland, United States

Publication history

  1. Received: June 5, 2018
  2. Accepted: October 4, 2018
  3. Accepted Manuscript published: October 5, 2018 (version 1)
  4. Version of Record published: October 11, 2018 (version 2)


© 2018, Huang et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.


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  1. Chengjie G Huang
  2. Michael G Metzen
  3. Maurice J Chacron
Feedback optimizes neural coding and perception of natural stimuli
eLife 7:e38935.

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