1. Neuroscience
Download icon

Stimulus background influences phase invariant coding by correlated neural activity

  1. Michael G Metzen
  2. Maurice J Chacron  Is a corresponding author
  1. McGill University, Canada
Research Advance
  • Cited 11
  • Views 754
  • Annotations
Cite this article as: eLife 2017;6:e24482 doi: 10.7554/eLife.24482


We recently reported that correlations between the activities of peripheral afferents mediate a phase invariant representation of natural communication stimuli that is refined across successive processing stages thereby leading to perception and behavior in the weakly electric fish Apteronotus leptorhynchus (Metzen et al., 2016). Here, we explore how phase invariant coding and perception of natural communication stimuli are affected by changes in the sinusoidal background over which they occur. We found that increasing background frequency led to phase locking, which decreased both detectability and phase invariant coding. Correlated afferent activity was a much better predictor of behavior as assessed from both invariance and detectability than single neuron activity. Thus, our results not only provide further evidence that correlated activity likely determines perception of natural communication signals, but also provide a novel explanation as to why these preferentially occur on top of low frequency as well as low intensity sinusoidal backgrounds.

Data availability

The following data sets were generated

Article and author information

Author details

  1. 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
  2. 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 (Operating grant)

  • Maurice J Chacron

Canada Research Chairs

  • 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 experimental procedures were approved by McGill University's animal care committee under protocol number 5285.

Reviewing Editor

  1. Ronald L Calabrese, Emory University, United States

Publication history

  1. Received: December 22, 2016
  2. Accepted: March 17, 2017
  3. Accepted Manuscript published: March 18, 2017 (version 1)
  4. Version of Record published: April 12, 2017 (version 2)


© 2017, Metzen & Chacron

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.


  • 754
    Page views
  • 145
  • 11

Article citation count generated by polling the highest count across the following sources: Crossref, Scopus, PubMed Central.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Download citations (links to download the citations from this article in formats compatible with various reference manager tools)

Open citations (links to open the citations from this article in various online reference manager services)

Further reading

    1. Neuroscience
    Yul HR Kang et al.
    Research Article Updated

    The brain is capable of processing several streams of information that bear on different aspects of the same problem. Here, we address the problem of making two decisions about one object, by studying difficult perceptual decisions about the color and motion of a dynamic random dot display. We find that the accuracy of one decision is unaffected by the difficulty of the other decision. However, the response times reveal that the two decisions do not form simultaneously. We show that both stimulus dimensions are acquired in parallel for the initial ∼0.1 s but are then incorporated serially in time-multiplexed bouts. Thus, there is a bottleneck that precludes updating more than one decision at a time, and a buffer that stores samples of evidence while access to the decision is blocked. We suggest that this bottleneck is responsible for the long timescales of many cognitive operations framed as decisions.

    1. Neuroscience
    Yu Takagi et al.
    Research Article

    Choices rely on a transformation of sensory inputs into motor responses. Using invasive single neuron recordings, the evolution of a choice process has been tracked by projecting population neural responses into state spaces. Here we develop an approach that allows us to recover similar trajectories on a millisecond timescale in non-invasive human recordings. We selectively suppress activity related to three task-axes, relevant and irrelevant sensory inputs and response direction in magnetoencephalography data acquired during context-dependent choices. Recordings from premotor cortex show a progression from processing sensory input to processing the response. In contrast to previous macaque recordings, information related to choice-irrelevant features is represented more weakly than choice-relevant sensory information. To test whether this mechanistic difference between species is caused by extensive overtraining common in non-human primate studies, we trained humans on >20,000 trials of the task. Choice-irrelevant features were still weaker than relevant features in premotor cortex after overtraining.