Cortical magnification eliminates differences in contrast sensitivity across but not around the visual field

Abstract
Data availability
Article and author information
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Abstract

Human visual performance changes dramatically both across (eccentricity) and around (polar angle) the visual field. Performance is better at the fovea, decreases with eccentricity, and is better along the horizontal than vertical meridian and along the lower than the upper vertical meridian. However, all neurophysiological and virtually all behavioral studies of cortical magnification have investigated eccentricity effects without considering polar angle. Most performance differences due to eccentricity are eliminated when stimulus size is cortically magnified (M-scaled) to equate the size of its cortical representation in primary visual cortex (V1). But does cortical magnification underlie performance differences around the visual field? Here, to assess contrast sensitivity, human adult observers performed an orientation discrimination task with constant stimulus size at different locations as well as when stimulus size was M-scaled according to stimulus eccentricity and polar angle location. We found that although M-scaling stimulus size eliminates differences across eccentricity, it does not eliminate differences around the polar angle. This finding indicates that limits in contrast sensitivity across eccentricity and around the visual field are mediated by different anatomical and computational constraints.

Data availability

Data and code pertaining to the experiment are available on the OSF repository (https://osf.io/gvkdh/; Jigo et al., 2023)

The following data sets were generated

(2023) Mscaling eliminates contrast sensitivity across not around.
OSF, doi:10.17605/OSF.IO/GVKDH.

https://osf.io/gvkdh/

Article and author information

Author details

Michael Jigo

Department of Psychology, New York University, New York City, United States

Competing interests
No competing interests declared.

"This ORCID iD identifies the author of this article:" 0000-0002-9742-4576
Daniel Tavdy

Department of Psychology, New York University, New York City, United States

Competing interests
No competing interests declared.
Marc Himmelberg

Department of Psychology, New York University, New York, United States

Competing interests
No competing interests declared.

"This ORCID iD identifies the author of this article:" 0000-0001-9133-7984
Marisa Carrasco

Department of Psychology, New York University, New York, United States

For correspondence
marisa.carrasco@nyu.edu

Competing interests
Marisa Carrasco, Reviewing editor, eLife.

"This ORCID iD identifies the author of this article:" 0000-0002-1002-9056

Funding

National Eye Institute (R01-EY027401)

Marisa Carrasco

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

Ethics

Human subjects: All observers provided written informed consent under the University Committee's protocol on Activities Involving Human Subjects at New York University agreeing to participate in the study and the public release of their data. All experimental procedures were approved by the Ethics Committee at the NYU Department of Psychology (IRB: FY2016-466) and were in agreement with the Declaration of Helsinki.

Copyright

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.