1. Neuroscience

Shorter cortical adaptation in dyslexia is broadly distributed in the superior temporal lobe and includes the primary auditory cortex

  1. Sagi Jaffe-Dax  Is a corresponding author
  2. Eva Kimel
  3. Merav Ahissar
  1. Princeton University, United States
  2. The Hebrew University of Jerusalem, Israel
https://doi.org/10.7554/eLife.30018
Share this article
Cite this article
  1. Sagi Jaffe-Dax
  2. Eva Kimel
  3. Merav Ahissar
(2018)
Shorter cortical adaptation in dyslexia is broadly distributed in the superior temporal lobe and includes the primary auditory cortex
eLife 7:e30018.
https://doi.org/10.7554/eLife.30018
  2. Download BibTeX
  3. Download .RIS

Abstract

Studies of performance of individuals with dyslexia on perceptual tasks suggest that their implicit inference of sound statistics is impaired. Previously, using two-tone frequency discrimination, we found that the effect of previous trials' frequencies on judgments of individuals with dyslexia decayed faster than the effect on controls' judgments, and that the adaptation (decrease of neural response to repeated stimuli) of their ERP responses to tones was shorter (Jaffe-Dax et al., 2017). Here, we show the cortical distribution of this abnormal dynamics of adaptation using fast acquisition fMRI. We find that faster decay of adaptation in dyslexia is widespread, though the most significant effects are found in the left superior temporal lobe, including the auditory cortex. This broad distribution suggests that the faster decay of implicit memory of individuals with dyslexia is a general characteristic of their cortical dynamics, which affects also sensory cortices.

Article and author information

Author details

  1. Sagi Jaffe-Dax

    Department of Psychology, Princeton University, Princeton, United States
    For correspondence
    jaffedax@princeton.edu
    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. Eva Kimel

    Edmond And Lily Safra Center for Brain Sciences, 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
    Competing interests
    The authors declare that no competing interests exist.

Funding

Israel Science Foundation (616/11)

  • Merav Ahissar

Gatsby Charitable Foundation

  • Merav Ahissar

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

  • Merav Ahissar

Israel Science Foundation (2425/15)

  • Merav Ahissar

Canadian Institute for Advanced Research

  • Merav Ahissar

Azrieli Foundation

  • Merav Ahissar

International Development Research Centre

  • 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.

Copyright

© 2018, 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.

Metrics

  • 1,339
    views
  • 189
    downloads
  • 33
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Citations by DOI

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)

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

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

  1. Sagi Jaffe-Dax
  2. Eva Kimel
  3. Merav Ahissar
(2018)
Shorter cortical adaptation in dyslexia is broadly distributed in the superior temporal lobe and includes the primary auditory cortex
eLife 7:e30018.
https://doi.org/10.7554/eLife.30018

Share this article

https://doi.org/10.7554/eLife.30018

Categories and tags

Research organism

Further reading

    1. Neuroscience

    Dyslexics’ faster decay of implicit memory for sounds and words is manifested in their shorter neural adaptation

    Sagi Jaffe-Dax, Or Frenkel, Merav Ahissar
    Research Article Updated

    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 by 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 of implicit memory also characterized the impact of sound regularities in benefitting dyslexics' oral reading rate. Their benefit 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 reduces their temporal window of integration of past stimuli, resulting in noisier and less reliable predictions for both simple and complex stimuli. Less reliable predictions limit their acquisition of reading expertise.