Suppression and facilitation of human neural responses

  1. Michael-Paul Schallmo  Is a corresponding author
  2. Alexander M Kale
  3. Rachel Millin
  4. Anastasia V Flevaris
  5. Zoran Brkanac
  6. Richard AE Edden
  7. Raphael A Bernier
  8. Scott Murray
  1. University of Washington, United States
  2. Johns Hopkins University, United States

Abstract

Efficient neural processing depends on regulating responses through suppression and facilitation of neural activity. Utilizing a well-known visual motion paradigm that evokes behavioral suppression and facilitation, and combining 5 different methodologies (behavioral psychophysics, computational modeling, functional MRI, pharmacology, and magnetic resonance spectroscopy), we provide evidence that challenges commonly held assumptions about the neural processes underlying suppression and facilitation. We show that: 1) both suppression and facilitation can emerge from a single, computational principle - divisive normalization; there is no need to invoke separate neural mechanisms, 2) neural suppression and facilitation in the motion-selective area MT mirror perception, but strong suppression also occurs in earlier visual areas, and 3) suppression is not primarily driven by GABA-mediated inhibition. Thus, while commonly used spatial suppression paradigms may provide insight into neural response magnitudes in visual areas, they should not be used to infer neural inhibition.

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Article and author information

Author details

  1. Michael-Paul Schallmo

    Department of Psychology, University of Washington, Seattle, United States
    For correspondence
    schallmo@uw.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-8252-8607
  2. Alexander M Kale

    Department of Psychology, University of Washington, Seattle, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-7668-2800
  3. Rachel Millin

    Department of Psychology, University of Washington, Seattle, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Anastasia V Flevaris

    Department of Psychology, University of Washington, Seattle, United States
    Competing interests
    The authors declare that no competing interests exist.
  5. Zoran Brkanac

    Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, United States
    Competing interests
    The authors declare that no competing interests exist.
  6. Richard AE Edden

    Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, United States
    Competing interests
    The authors declare that no competing interests exist.
  7. Raphael A Bernier

    Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, United States
    Competing interests
    The authors declare that no competing interests exist.
  8. Scott Murray

    Department of Psychology, University of Washington, Seattle, United States
    Competing interests
    The authors declare that no competing interests exist.

Funding

National Eye Institute (F32 EY025121)

  • Michael-Paul Schallmo
  • Scott Murray

National Institute of Mental Health (R01 MH106520)

  • Raphael A Bernier
  • Scott Murray

National Institute of Biomedical Imaging and Bioengineering (P41 EB015909)

  • Richard AE Edden

National Eye Institute (T32 EY007031)

  • Michael-Paul Schallmo
  • Scott Murray

National Institute of Biomedical Imaging and Bioengineering (R01 EB016089)

  • Richard AE Edden

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

Ethics

Human subjects: Subjects provided written informed consent prior to participation and were compensated for their time. All experimental procedures were approved by the University of Washington Institutional Review Board (protocol #s: 556, 1678, 28148), and conformed to the ethical principles for research on human subjects from the Declaration of Helsinki.

Copyright

© 2018, Schallmo 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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