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Dissociation of task engagement and arousal effects in auditory cortex and midbrain

  1. Daniela Saderi
  2. Zachary P Schwartz
  3. Charles R Heller
  4. Jacob R Pennington
  5. Stephen V David  Is a corresponding author
  1. Oregon Health and Science University, United States
  2. Washington State University, United States
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Cite this article as: eLife 2021;10:e60153 doi: 10.7554/eLife.60153

Abstract

Both generalized arousal and engagement in a specific task influence sensory neural processing. To isolate effects of these state variables in the auditory system, we recorded single-unit activity from primary auditory cortex (A1) and inferior colliculus (IC) of ferrets during a tone detection task, while monitoring arousal via changes in pupil size. We used a generalized linear model to assess the influence of task engagement and pupil size on sound-evoked activity. In both areas, these two variables affected independent neural populations. Pupil size effects were more prominent in IC, while pupil and task engagement effects were equally likely in A1. Task engagement was correlated with larger pupil; thus, some apparent effects of task engagement should in fact be attributed to fluctuations in pupil size. These results indicate a hierarchy of auditory processing, where generalized arousal enhances activity in midbrain, and effects specific to task engagement become more prominent in cortex.

Data availability

Neurophysiology data will be made available via Zenodo. Software used for analysis is available via GitHub.

The following data sets were generated

Article and author information

Author details

  1. Daniela Saderi

    Neuroscience Graduate Program, Oregon Health and Science University, Portland, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Zachary P Schwartz

    Neuroscience Graduate Program, Oregon Health and Science University, Portland, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Charles R Heller

    Neuroscience Graduate Program, Oregon Health and Science University, Portland, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Jacob R Pennington

    Mathematics, Washington State University, Vancouver, United States
    Competing interests
    The authors declare that no competing interests exist.
  5. Stephen V David

    Otolaryngology, Oregon Health and Science University, Portland, United States
    For correspondence
    davids@ohsu.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-4135-3104

Funding

National Institutes of Health (F31 DC014888)

  • Daniela Saderi

National Institutes of Health (R01 DC04950)

  • Stephen V David

National Institutes of Health (R01 EB028155)

  • Stephen V David

National Institutes of Health (F31 DC016204)

  • Zachary P Schwartz

National Science Foundation (GVPRS0015A2)

  • Charles R Heller

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

Ethics

Animal experimentation: All procedures were approved by the Oregon Health and Science University Institutional Animal Care and Use Committee (protocol IP1561) and conform to National Institutes of Health standards.

Reviewing Editor

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

Publication history

  1. Received: June 17, 2020
  2. Accepted: February 10, 2021
  3. Accepted Manuscript published: February 11, 2021 (version 1)
  4. Version of Record published: February 26, 2021 (version 2)

Copyright

© 2021, Saderi 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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