The visual system is continuously recalibrated through processes of adaptation that adjust sensitivity in response to changes in the environment or the observer. These adaptive adjustments operate throughout the visual system and thus profoundly influence most if not all aspects of visual perception. Most prior studies of visual adaptation have focused on sensitivity changes over short times scales ranging from milliseconds to minutes. However, there are increasing theoretical arguments and empirical evidence that these rapid adjustments are superimposed on response changes that influence visual coding over much longer durations. These long-term forms of adaptation may be the primary mechanisms for setting the baseline operating states of the visual system, and may be especially important for compensating visual coding for the gradual but pronounced changes in optical and neural properties of the visual system that occur throughout the lifespan. Yet almost nothing is known about the nature or properties of adaptation at longer timescales, or about which attributes of the visual stimulus they can adjust to. The proposed research will provide a systematic investigation of long-term visual adaptation through a series of studies that will probe the mechanisms and sites of long-term sensitivity adjustments and their consequences for visual perception and visual performance.
Specific Aim 1 will probe the effects of adaptation to changes in the average color of the environment or in the spectral sensitivity of the observer, and how these effects arise from sensitivity changes at both retinal and cortical sites.
Specific Aim 2 will test whether the long-term response changes demonstrated for color are also manifest for other stimulus attributes, including the cortical mechanisms mediating contrast and blur perception as well as high-level aftereffects for face recognition. These experiments will help to reveal whether long-term adaptation plays a general or specialized role in calibrating visual responses.
Aim 3 will test whether the functional form of the response changes differs at short and long timescales, and thus whether they are designed to adapt visual coding for different aspects of the stimulus. Finally, Aim 4 will explore the consequences of long-term adaptation for optimizing visual coding. These experiments will include altering the color characteristics of images to simulate how they should appear under theoretically complete adaptation, and then testing how well observers can respond to information in these pre-adapted images. The results of these studies will help to reveal the mechanisms, properties, and consequences of adaptation processes that are likely to play a central role in normal visual function but which remain largely unexplored.

Public Health Relevance

The processes of adaptation are critical for maintaining normal visual function. The proposed experiments will help to reveal how the visual system adapts to changes in the environment or to the optical and neural changes that result from normal development and aging or disease.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY010834-16
Application #
8702182
Study Section
Special Emphasis Panel (ZRG1-IFCN-Q (02))
Program Officer
Wiggs, Cheri
Project Start
1994-12-01
Project End
2016-07-31
Budget Start
2014-08-01
Budget End
2015-07-31
Support Year
16
Fiscal Year
2014
Total Cost
$278,402
Indirect Cost
$82,402
Name
University of Nevada Reno
Department
Psychology
Type
Schools of Arts and Sciences
DUNS #
146515460
City
Reno
State
NV
Country
United States
Zip Code
89557
Webster, Jacquelyn; Kay, Paul; Webster, Michael A (2014) Perceiving the average hue of color arrays. J Opt Soc Am A Opt Image Sci Vis 31:A283-92
O'Neil, Sean F; Webster, Michael A (2014) Filling in, filling out, or filtering out: processes stabilizing color appearance near the center of gaze. J Opt Soc Am A Opt Image Sci Vis 31:A140-7
Tregillus, Katherine; Webster, Michael A (2014) Dynamics of color contrast adaptation. J Opt Soc Am A Opt Image Sci Vis 31:A314-21
Webster, Michael A (2014) Probing the functions of contextual modulation by adapting images rather than observers. Vision Res 104:68-79
Kompaniez, Elysse; Sawides, Lucie; Marcos, Susana et al. (2013) Adaptation to interocular differences in blur. J Vis 13:19
Mizokami, Yoko; Webster, Michael A (2012) Are Gaussian spectra a viable perceptual assumption in color appearance? J Opt Soc Am A Opt Image Sci Vis 29:A10-8
O'Neil, Sean F; McDermott, Kyle C; Mizokami, Yoko et al. (2012) Tests of a functional account of the Abney effect. J Opt Soc Am A Opt Image Sci Vis 29:A165-73
McDermott, Kyle C; Webster, Michael A (2012) Uniform color spaces and natural image statistics. J Opt Soc Am A Opt Image Sci Vis 29:A182-7
McDermott, Kyle C; Webster, Michael A (2012) The perceptual balance of color. J Opt Soc Am A Opt Image Sci Vis 29:A108-17
Sawides, Lucie; de Gracia, Pablo; Dorronsoro, Carlos et al. (2011) Vision is adapted to the natural level of blur present in the retinal image. PLoS One 6:e27031

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