This research investigates visual processes that mediate perception of color and brightness in complex scenes. It is well known that the appearance of an objective in a natural scene does not depend on only the light reflected from the object. A light in one part of the visual field can affect the appearance of another light. Most previous research has employed very simple visual stimuli (for example, a small test patch on a chromatic adapting background or within a chromatic surround) to explore the visual mechanisms by which one light affects another. While this work has revealed fundamental properties of the visual pathway, there is widespread agreement that perception of color and brightness in complex scenes cannot be fully explained by these mechanisms. Quantitative studies of color and brightness in complex visual displays rarely have been designed to seek properties of the human visual system. Many of these studies measured changes in appearance caused by altering the spectral distribution of the illuminating light. Recent theoretical models suggest how information implicit in receptoral quantal absorptions may be exploited to maintain (approximate) color constancy. This work, however, seldom considers the neural processes that must be involved. The research proposed here will isolate and quantitatively assess neural processes, beyond mechanisms of simple chromatic adaptation and contrast, that mediate the color and brightness of complex visual stimuli. Recent results from my laboratory reveal that such processes are observed with even """"""""slightly complex"""""""" stimuli (e.g., a chromatic adapting background with a small region of superimposed achromatic light some distance away from the test patch). By presenting a test light on an adapting field and varying another light in a region not adjacent to the test, changes in color and brightness of the test are measured while contrast (at the edge of the test) is held constant. Properties of neural mechanisms beyond adaptation and contrast will be determined by varying the features (e.g., size, location, chromaticity, retinal illuminance, homogeneity) of nonadjacent light. Visual mechanisms in monocular and in central binocular pathways will be distinguished using haploscopically presented stimuli. A long-term goal of this research is to provide sensitive and reliable psychophysical techniques to aid in the diagnosis of eye disorders.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY004802-12
Application #
2159158
Study Section
Visual Sciences B Study Section (VISB)
Project Start
1983-09-01
Project End
1996-08-31
Budget Start
1994-09-01
Budget End
1995-08-31
Support Year
12
Fiscal Year
1994
Total Cost
Indirect Cost
Name
University of Chicago
Department
Psychology
Type
Schools of Arts and Sciences
DUNS #
225410919
City
Chicago
State
IL
Country
United States
Zip Code
60637
Elliott, Sarah L; Shevell, Steven K (2018) Illusory edges comingle with real edges in the neural representation of objects. Vision Res 144:47-51
Shevell, Steven K; Wang, Wei (2016) Color-motion feature-binding errors are mediated by a higher-order chromatic representation. J Opt Soc Am A Opt Image Sci Vis 33:A85-92
Stepien, Natalie N; Shevell, Steven K (2015) The role of color in motion feature-binding errors. J Vis 15:8
D'Antona, Anthony D; Christiansen, Jens H; Shevell, Steven K (2014) Separating monocular and binocular neural mechanisms mediating chromatic contextual interactions. J Vis 14:
Wang, Wei; Shevell, Steven K (2014) Do S cones contribute to color-motion feature binding? J Opt Soc Am A Opt Image Sci Vis 31:A60-4
Elliott, Sarah L; Shevell, Steven K (2013) Perceived segmentation of center from surround by only illusory contours causes chromatic lateral inhibition. Vision Res 86:66-70
Allen, Elizabeth C; Beilock, Sian L; Shevell, Steven K (2012) Individual differences in simultaneous color constancy are related to working memory. J Opt Soc Am A Opt Image Sci Vis 29:A52-9
Kang, Para; Shevell, Steven K (2012) Feature binding of a continuously changing object. J Opt Soc Am A Opt Image Sci Vis 29:A128-32
Shevell, Steven K (2012) The Verriest Lecture: color lessons from space, time and motion. J Opt Soc Am A Opt Image Sci Vis 29:A337-45
Autrusseau, Florent; Thibos, Larry; Shevell, Steven K (2011) Chromatic and wavefront aberrations: L-, M- and S-cone stimulation with typical and extreme retinal image quality. Vision Res 51:2282-94

Showing the most recent 10 out of 78 publications