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Modeling individual variations in equiluminance settings
Recently, we reported measurements of heterochromatic flicker photometry (HFP) in 22 young observers, with stimuli that (nominally) modulated only L- and M-cones and were kept at (approximately) a constant multiple of detection threshold. These equiluminance settings were represented as the angle in...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The Association for Research in Vision and Ophthalmology
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8322724/ https://www.ncbi.nlm.nih.gov/pubmed/34313713 http://dx.doi.org/10.1167/jov.21.7.15 |
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author | He, Jingyi Taveras-Cruz, Yesenia Eskew, Rhea T. |
author_facet | He, Jingyi Taveras-Cruz, Yesenia Eskew, Rhea T. |
author_sort | He, Jingyi |
collection | PubMed |
description | Recently, we reported measurements of heterochromatic flicker photometry (HFP) in 22 young observers, with stimuli that (nominally) modulated only L- and M-cones and were kept at (approximately) a constant multiple of detection threshold. These equiluminance settings were represented as the angle in the (L, M) cone contrast plane, with the greenish peak of the flicker in quadrant II and the reddish peak in quadrant IV; equiluminance settings were reported as the greenish angle. The mean equiluminance angle was 116.3° (an M:L cone contrast ratio of −2 at equiluminance), but individual differences in the settings were substantial, with the variation across individuals almost five times larger than the within-subject precision in the settings. In the present study we sought to determine the degree to which we could account for our observers’ HFP settings by plausible variations in the macular pigment optical density (MPOD), the lens pigment optical density (LPOD), the cone photopigment optical densities (PPOD), and serine/alanine polymorphism in L-cone opsin (λ(max) shift). Most of the range of our measured equiluminance angles could be accounted for by these factors, although the largest two angles (smallest |ΔM/M: ΔL/L| ratio at equiluminance) could not. Individual differences in HFP have sometimes been taken to indicate variations in the ratio of L:M cone number; our results suggest that most of the individual differences in HFP might be equally well ascribed to physiological factors other than cone number. Simple linear models allow predictions of equiluminance angle, cone adapting level, and artifactual S-cone contrast from the values of the four factors considered here. |
format | Online Article Text |
id | pubmed-8322724 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | The Association for Research in Vision and Ophthalmology |
record_format | MEDLINE/PubMed |
spelling | pubmed-83227242021-08-13 Modeling individual variations in equiluminance settings He, Jingyi Taveras-Cruz, Yesenia Eskew, Rhea T. J Vis Article Recently, we reported measurements of heterochromatic flicker photometry (HFP) in 22 young observers, with stimuli that (nominally) modulated only L- and M-cones and were kept at (approximately) a constant multiple of detection threshold. These equiluminance settings were represented as the angle in the (L, M) cone contrast plane, with the greenish peak of the flicker in quadrant II and the reddish peak in quadrant IV; equiluminance settings were reported as the greenish angle. The mean equiluminance angle was 116.3° (an M:L cone contrast ratio of −2 at equiluminance), but individual differences in the settings were substantial, with the variation across individuals almost five times larger than the within-subject precision in the settings. In the present study we sought to determine the degree to which we could account for our observers’ HFP settings by plausible variations in the macular pigment optical density (MPOD), the lens pigment optical density (LPOD), the cone photopigment optical densities (PPOD), and serine/alanine polymorphism in L-cone opsin (λ(max) shift). Most of the range of our measured equiluminance angles could be accounted for by these factors, although the largest two angles (smallest |ΔM/M: ΔL/L| ratio at equiluminance) could not. Individual differences in HFP have sometimes been taken to indicate variations in the ratio of L:M cone number; our results suggest that most of the individual differences in HFP might be equally well ascribed to physiological factors other than cone number. Simple linear models allow predictions of equiluminance angle, cone adapting level, and artifactual S-cone contrast from the values of the four factors considered here. The Association for Research in Vision and Ophthalmology 2021-07-27 /pmc/articles/PMC8322724/ /pubmed/34313713 http://dx.doi.org/10.1167/jov.21.7.15 Text en Copyright 2021 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 | Article He, Jingyi Taveras-Cruz, Yesenia Eskew, Rhea T. Modeling individual variations in equiluminance settings |
title | Modeling individual variations in equiluminance settings |
title_full | Modeling individual variations in equiluminance settings |
title_fullStr | Modeling individual variations in equiluminance settings |
title_full_unstemmed | Modeling individual variations in equiluminance settings |
title_short | Modeling individual variations in equiluminance settings |
title_sort | modeling individual variations in equiluminance settings |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8322724/ https://www.ncbi.nlm.nih.gov/pubmed/34313713 http://dx.doi.org/10.1167/jov.21.7.15 |
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