Coding of chromatic spatial contrast by macaque V1 neurons

  1. Abhishek De
  2. Gregory D Horwitz  Is a corresponding author
  1. University of Washington, United States


Color perception relies on comparisons between adjacent lights, but how the brain performs these comparisons is poorly understood. To elucidate the underlying neural mechanisms, we recorded spiking responses of individual V1 neurons in macaque monkeys to pairs of stimuli within the classical receptive field (RF). We estimated the spatial-chromatic RF of each neuron and then presented customized colored edges using a novel closed-loop technique. We found that many double-opponent (DO) cells, which have spatially and chromatically opponent RFs, responded to chromatic contrast as a weighted sum, akin to how other V1 cells responded to luminance contrast. Yet other neurons integrated chromatic signals non-linearly, confirming that linear signal integration is not an obligate property of V1 neurons. The functional similarity of cone-opponent DO cells and cone non-opponent simple cells suggests that these two groups may share a common underlying neural circuitry, promotes the construction of image-computable models for full-color image representation, and sheds new light on V1 complex cells.

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Author details

  1. Abhishek De

    Department of Physiology and Biophysics, 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:" 0000-0002-2978-473X
  2. Gregory D Horwitz

    Department of Physiology and Biophysics, University of Washington, Seattle, United States
    For correspondence
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-5130-5259


National Eye Institute (EY018849)

  • Gregory D Horwitz

Office of the Director (OD010425)

  • Gregory D Horwitz

National Eye Institute (EY01730)

  • Gregory D Horwitz

National Institute on Drug Abuse (DA033461)

  • Abhishek De

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


Animal experimentation: This study was performed in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. All of the animals were handled according to approved institutional animal care and use committee (IACUC) protocol (#4167-01) of the University of Washington. All surgery was performed under sevoflurane anesthesia, and every effort was made to minimize suffering.

Reviewing Editor

  1. Tatiana Pasternak, National Institute of Neurological Disorders and Stroke, United States

Version history

  1. Preprint posted: February 14, 2021 (view preprint)
  2. Received: March 5, 2021
  3. Accepted: February 1, 2022
  4. Accepted Manuscript published: February 11, 2022 (version 1)
  5. Version of Record published: March 14, 2022 (version 2)


© 2022, De & Horwitz

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. Abhishek De
  2. Gregory D Horwitz
Coding of chromatic spatial contrast by macaque V1 neurons
eLife 11:e68133.

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