1. Neuroscience
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Dyslexics' faster decay of implicit memory for sounds and words is manifested in their shorter neural adaptation

  1. Sagi Jaffe-Dax  Is a corresponding author
  2. Orr Frenkel
  3. Merav Ahissar  Is a corresponding author
  1. The Hebrew University of Jerusalem, Israel
Research Article
  • Cited 19
  • Views 4,223
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Cite this article as: eLife 2017;6:e20557 doi: 10.7554/eLife.20557

Abstract

Dyslexia is a prevalent reading disability whose underlying mechanisms are still disputed. We studied the neural mechanisms underlying dyslexia using a simple frequency-discrimination task. Though participants were asked to compare the two tones in each trial, implicit memory of previous trials affected their responses. We hypothesized that implicit memory decays faster among dyslexics. We tested this by increasing the temporal intervals between consecutive trials, and measuring the behavioral impact and ERP responses from the auditory cortex. Dyslexics showed a faster decay of implicit memory effects on both measures, with similar time constants. Finally, faster decay also characterized dyslexics' benefits in oral reading rate. It decreased faster as a function of the time interval from the previous reading of the same non-word. We propose that dyslexics' shorter neural adaptation paradoxically accounts for their longer reading times, since it induces noisier and less reliable predictions for both simple and complex stimuli.

Article and author information

Author details

  1. Sagi Jaffe-Dax

    Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
    For correspondence
    sagi.jaffe@mail.huji.ac.il
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-8759-6980
  2. Orr Frenkel

    Psychology Department, The Hebrew University of Jerusalem, Jerusalem, Israel
    Competing interests
    The authors declare that no competing interests exist.
  3. Merav Ahissar

    Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
    For correspondence
    msmerava@gmail.com
    Competing interests
    The authors declare that no competing interests exist.

Funding

Israel Science Foundation (616/11)

  • Merav Ahissar

Israel Science Foundation (2425/15)

  • Merav Ahissar

Gatsby Charitable Foundation

  • Merav Ahissar

EPFL-HUJI collaboration

  • Merav Ahissar

German-Israeli Foundation for Scientific Research and Development (I-1303-105.4/2015)

  • Merav Ahissar

Canadian Institutes of Health Research

  • Merav Ahissar

International Development Research Centre

  • Merav Ahissar

Azrieli Foundation

  • Merav Ahissar

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

Ethics

Human subjects: Informed consent was acquired from all participants. The study was approved by The Hebrew University Committee for the Use of Human Subject in Research.

Reviewing Editor

  1. Andrew J King, University of Oxford, United Kingdom

Publication history

  1. Received: August 12, 2016
  2. Accepted: January 9, 2017
  3. Accepted Manuscript published: January 24, 2017 (version 1)
  4. Version of Record published: January 30, 2017 (version 2)

Copyright

© 2017, Jaffe-Dax 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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