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Delayed S-cone sensitivity losses following the onset of intense yellow backgrounds linked to the lifetime of a photobleaching product?

Stockman, A; Henning, B; Smithson, H; Rider, A; (2018) Delayed S-cone sensitivity losses following the onset of intense yellow backgrounds linked to the lifetime of a photobleaching product? Journal of Vision , 18 (6) 10.1167/18.6.12. Green open access

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Abstract

Thirty years ago, Mollon, Stockman, & Polden (1987) reported that after the onset of intense yellow 581-nm backgrounds, S-cone threshold rose unexpectedly for several seconds before recovering to the light-adapted steady-state value—an effect they called: ‘‘transienttritanopia of the second kind’’ (TT2). Given that 581- nm lights have little direct effect on S-cones, TT2 must arise indirectly from the backgrounds’ effects on the Land M-cones. We attribute the phenomenon to the action of an unknown L- and M-cone photobleaching product, X, which acts at their outputs like an ‘‘equivalent’’ background light that then inhibits Scones at a cone-opponent, second-site. The timecourse of TT2 is similar in form to the lifetime of X in a two-stage, first-order biochemical reaction A-X-C with successive best-fitting time-constants of 3.09 6 0.35 and 7.73 6 0.70 s. Alternatively, with an additional slowly recovering exponential ‘‘restoringforce’’ with a best-fitting time-constant 23.94 6 1.42 s, the two-stage best-fitting time-constants become 4.15 6 0.62 and 6.79 6 1.00 s. Because the time-constants are roughly independent of the background illumination, and thus the rate of photoisomerization, A-X is likely to be a reaction subsidiary to the retinoid cycle, perhaps acting as a buffer when the bleaching rate is too high. X seems to be logarithmically related to S-cone threshold, which may result from the logarithmic cone-opponent, second-site response compression after multiplicative first-site adaptation. The restoring-force may be the same coneopponent force that sets the rate of S-cone recovery following the unusual threshold increase following the offset of dimmer yellow backgrounds, an effect known as ‘‘transient-tritanopia’’ (TT1).

Type: Article
Title: Delayed S-cone sensitivity losses following the onset of intense yellow backgrounds linked to the lifetime of a photobleaching product?
Open access status: An open access version is available from UCL Discovery
DOI: 10.1167/18.6.12
Publisher version: https://doi.org/10.1167/18.6.12
Language: English
Additional information: This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
UCL classification: UCL
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences > Institute of Ophthalmology
URI: https://discovery.ucl.ac.uk/id/eprint/10051660
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