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Illumination discrimination in real and simulated scenes

Lookup NU author(s): Bradley Pearce, Stacey Aston, Professor Anya Hurlbert



This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).


Characterizing humans' ability to discriminate changes in illumination provides information about the visual system's representation of the distal stimulus. We have previously shown that humans are able to discriminate illumination changes and that sensitivity to such changes depends on their chromatic direction. Probing illumination discrimination further would be facilitated by the use of computer-graphics simulations, which would, in practice, enable a wider range of stimulus manipulations. There is no a priori guarantee, however, that results obtained with simulated scenes generalize to real illuminated scenes. To investigate this question, we measured illumination discrimination in real and simulated scenes that were well-matched in mean chromaticity and scene geometry. Illumination discrimination thresholds were essentially identical for the two stimulus types. As in our previous work, these thresholds varied with illumination change direction. We exploited the flexibility offered by the use of graphics simulations to investigate whether the differences across direction are preserved when the surfaces in the scene are varied. We show that varying the scene's surface ensemble in a manner that also changes mean scene chromaticity modulates the relative sensitivity to illumination changes along different chromatic directions. Thus, any characterization of sensitivity to changes in illumination must be defined relative to the set of surfaces in the scene.

Publication metadata

Author(s): Radonjic A, Pearce B, Aston S, Krieger A, Dubin H, Cottaris NP, Brainard DH, Hurlbert AC

Publication type: Article

Publication status: Published

Journal: Journal of Vision

Year: 2016

Volume: 16

Issue: 11

Online publication date: 01/09/2016

Acceptance date: 02/04/2016

Date deposited: 20/03/2017

ISSN (electronic): 1534-7362

Publisher: Association for Research in Vision and Ophthalmology


DOI: 10.1167/16.11.2


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Funder referenceFunder name
102562/Z/13/ZWellcome Trust
324759Simons Foundation Collaboration on the Global Brain Grant
EP/H022325/1EPSRC UK
P30 EY001583NIH
RO1 EY10016NIH