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Blur Representation in the Amblyopic Visual System Using Natural and Synthetic Images

PURPOSE: Amblyopia is diagnosed as a reduced acuity in an otherwise healthy eye, which indicates that the deficit is not happening in the eye, but in the brain. One suspected mechanism explaining these deficits is an elevated amount of intrinsic blur in the amblyopic visual system compared to health...

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Autores principales: Abbas Farishta, Reza, Yang, Charlene L., Farivar, Reza
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Association for Research in Vision and Ophthalmology 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8742520/
https://www.ncbi.nlm.nih.gov/pubmed/34982147
http://dx.doi.org/10.1167/iovs.63.1.3
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author Abbas Farishta, Reza
Yang, Charlene L.
Farivar, Reza
author_facet Abbas Farishta, Reza
Yang, Charlene L.
Farivar, Reza
author_sort Abbas Farishta, Reza
collection PubMed
description PURPOSE: Amblyopia is diagnosed as a reduced acuity in an otherwise healthy eye, which indicates that the deficit is not happening in the eye, but in the brain. One suspected mechanism explaining these deficits is an elevated amount of intrinsic blur in the amblyopic visual system compared to healthy observers. This “internally produced blur” can be estimated by the “equivalent intrinsic blur method”, which measures blur discrimination thresholds while systematically increasing the external blur in the physical stimulus. Surprisingly, amblyopes do not exhibit elevated intrinsic blur when measured with an edge stimulus. Given the fundamental ways in which they differ, synthetic stimuli, such as edges, are likely to generate contrasting blur perception compared to natural stimuli, such as pictures. Because our visual system is presumably tuned to process natural stimuli, testing artificial stimuli only could result in performances that are not ecologically valid. METHODS: We tested this hypothesis by measuring, for the first time, the perception of blur added to natural images in amblyopia and compared discrimination performance for natural images and synthetic edges in healthy and amblyopic groups. RESULTS: Our results demonstrate that patients with amblyopia exhibit higher levels of intrinsic blur than control subjects when tested on natural images. This difference was not observed when using edges. CONCLUSIONS: Our results suggest that intrinsic blur is elevated in the visual system representing vision from the amblyopic eye and that distinct statistics of images can generate different blur perception.
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spelling pubmed-87425202022-01-14 Blur Representation in the Amblyopic Visual System Using Natural and Synthetic Images Abbas Farishta, Reza Yang, Charlene L. Farivar, Reza Invest Ophthalmol Vis Sci Visual Psychophysics and Physiological Optics PURPOSE: Amblyopia is diagnosed as a reduced acuity in an otherwise healthy eye, which indicates that the deficit is not happening in the eye, but in the brain. One suspected mechanism explaining these deficits is an elevated amount of intrinsic blur in the amblyopic visual system compared to healthy observers. This “internally produced blur” can be estimated by the “equivalent intrinsic blur method”, which measures blur discrimination thresholds while systematically increasing the external blur in the physical stimulus. Surprisingly, amblyopes do not exhibit elevated intrinsic blur when measured with an edge stimulus. Given the fundamental ways in which they differ, synthetic stimuli, such as edges, are likely to generate contrasting blur perception compared to natural stimuli, such as pictures. Because our visual system is presumably tuned to process natural stimuli, testing artificial stimuli only could result in performances that are not ecologically valid. METHODS: We tested this hypothesis by measuring, for the first time, the perception of blur added to natural images in amblyopia and compared discrimination performance for natural images and synthetic edges in healthy and amblyopic groups. RESULTS: Our results demonstrate that patients with amblyopia exhibit higher levels of intrinsic blur than control subjects when tested on natural images. This difference was not observed when using edges. CONCLUSIONS: Our results suggest that intrinsic blur is elevated in the visual system representing vision from the amblyopic eye and that distinct statistics of images can generate different blur perception. The Association for Research in Vision and Ophthalmology 2022-01-04 /pmc/articles/PMC8742520/ /pubmed/34982147 http://dx.doi.org/10.1167/iovs.63.1.3 Text en Copyright 2022 The Authors https://creativecommons.org/licenses/by-nc-nd/4.0/This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
spellingShingle Visual Psychophysics and Physiological Optics
Abbas Farishta, Reza
Yang, Charlene L.
Farivar, Reza
Blur Representation in the Amblyopic Visual System Using Natural and Synthetic Images
title Blur Representation in the Amblyopic Visual System Using Natural and Synthetic Images
title_full Blur Representation in the Amblyopic Visual System Using Natural and Synthetic Images
title_fullStr Blur Representation in the Amblyopic Visual System Using Natural and Synthetic Images
title_full_unstemmed Blur Representation in the Amblyopic Visual System Using Natural and Synthetic Images
title_short Blur Representation in the Amblyopic Visual System Using Natural and Synthetic Images
title_sort blur representation in the amblyopic visual system using natural and synthetic images
topic Visual Psychophysics and Physiological Optics
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8742520/
https://www.ncbi.nlm.nih.gov/pubmed/34982147
http://dx.doi.org/10.1167/iovs.63.1.3
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