Perception in autism does not adhere to Weber's law

  1. Bat-Sheva Hadad  Is a corresponding author
  2. Sivan Schwartz
  1. University of Haifa, Israel


Perceptual atypicalities are a widely acknowledged but poorly understood feature of autism. We demonstrate here a striking violation of one of the most adaptive psychophysical computations - Weber's law - in high-functioning individuals with autism. JNDs based on the best-fitting psychometric functions were measured for size visual judgments (Exp. 1), weight haptic discrimination (Exp. 2), and illusive perception of weight (brightness-weight illusion; Exp. 3). Results for the typically developed group confirmed Weber's law, demonstrating a linear increase in JNDs with intensity, resulting in constant fractions across intensities. The results for the ASD, in contrast, showed no scaling of JNDs with intensity; instead, fractions decreased linearly with intensity. In striking contrast to its consistency in typical perception, Weber's law does not hold for visual and haptic perception in autism. These robust modulations in psychophysical computations, demonstrated for different domains of perception, suggest a modality-independent, low-level mechanism driving altered perception in autism.

Data availability

Data can be found in

The following data sets were generated
    1. Hadad B-S
    (2018) Weber in Autism
    Open Science Framework, ckmhq.

Article and author information

Author details

  1. Bat-Sheva Hadad

    Edmond J Safra Brain Research Center, University of Haifa, Haifa, Israel
    For correspondence
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-3159-8696
  2. Sivan Schwartz

    Department of Psychology, University of Haifa, Haifa, Israel
    Competing interests
    The authors declare that no competing interests exist.


Israel Science Foundation (967/14)

  • Bat-Sheva Hadad

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


Human subjects: All procedures were approved by the Ethical Committee of the Faculty of Education, University of Haifa (Perceptual Processing in ASD: approval number 016/15). Adults who were students at the University of Haifa received course credit, children received a gift card, and individuals with ASD were paid 50NIS per hour to compensate them for their time.

Reviewing Editor

  1. Marisa Carrasco, New York University, United States

Publication history

  1. Received: September 21, 2018
  2. Accepted: March 1, 2019
  3. Accepted Manuscript published: March 4, 2019 (version 1)
  4. Version of Record published: March 15, 2019 (version 2)


© 2019, Hadad & Schwartz

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. Bat-Sheva Hadad
  2. Sivan Schwartz
Perception in autism does not adhere to Weber's law
eLife 8:e42223.

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