The goal of this project is to use flicker and flicker interactions to understand more about vision and visual perception. A common theme throughout is the combination of measures of flicker sensitivity and flicker delay (between signals generated by different receptor types or by the same receptor types but in different eyes) to reveal the inner workings of the visual system. Two related areas of study are proposed: (I) Organization of the early visual system The phase delays and amplitudes of the middle-wavelength (M) and long- wavelength (L) cone inputs to the channel(s) that signal flicker will be systematically analyzed under various adaptational conditions. Preliminary evidence shows that the data can be modeled by assuming that slow (+MS-LS or +LS-MS) as well as fast (+Mf+Lf) cone signals feed into the achromatic channel ( - means inverted in sign, + non-inverted, f fast and s slow). (II) Light adaptation of the visual system Measures of the delay between flicker signals generated by the two eyes under different states of adaptation will be combined with measures of flicker sensitivity to characterize the effects of light adaptation more completely than has been done before. Armed with this newly won information, we will critically evaluate current models of light adaptation and develop new ones. Our preliminary results have led to the development of an elegant model that requires just two parameters to account for light adaptation over a range of luminances of greater than 105. Measurements will be aimed first at adaptation in M and L-cone pathways, and then at adaptation in short-wavelength (S) cone and rod pathways. Our results, we believe, will: (I) force a radical reappraisal of the way in which color-opponent and luminance signals are assumed to interact, lead to a more realistic psychological model of the organization of the early visual system, and require modifications to current models of the luminance channel; and (II) allow a critical reassessment and reformulation of models of light adaptation. In each case, we will relate our results to, and be guided by, the underlying retinal physiology and anatomy. Present knowledge of physiology and anatomy reveals a more complicated system than the canonical psychophysical model of luminance and chromatic channels. Our work, which identifies complex flicker interactions between fast and slow signals from the three cone types that are also seen in records from macaque ganglion cells will provide a link to current physiological and anatomical studies, and, we hope, motivate new ones.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
2R01EY010206-06A1
Application #
2904638
Study Section
Visual Sciences B Study Section (VISB)
Project Start
1993-07-01
Project End
2003-06-30
Budget Start
1999-07-01
Budget End
2000-06-30
Support Year
6
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of California San Diego
Department
Psychology
Type
Schools of Arts and Sciences
DUNS #
077758407
City
La Jolla
State
CA
Country
United States
Zip Code
92093
Stockman, Andrew; Langendorfer, Micha; Sharpe, Lindsay T (2007) Human short-wavelength-sensitive cone light adaptation. J Vis 7:4
Stockman, Andrew; Montag, Ethan D; Plummer, Daniel J (2006) Paradoxical shifts in human color sensitivity caused by constructive and destructive interference between signals from the same cone class. Vis Neurosci 23:471-8
Stockman, Andrew; Plummer, Daniel J (2005) Spectrally opponent inputs to the human luminance pathway: slow +L and -M cone inputs revealed by low to moderate long-wavelength adaptation. J Physiol 566:77-91
Stockman, Andrew; Plummer, Daniel J (2005) Long-wavelength adaptation reveals slow, spectrally opponent inputs to the human luminance pathway. J Vis 5:702-16
Stockman, Andrew; Plummer, Daniel J; Montag, Ethan D (2005) Spectrally opponent inputs to the human luminance pathway: slow +M and -L cone inputs revealed by intense long-wavelength adaptation. J Physiol 566:61-76
Stockman, A; Sharpe, L T (2000) The spectral sensitivities of the middle- and long-wavelength-sensitive cones derived from measurements in observers of known genotype. Vision Res 40:1711-37
Stockman, A; Sharpe, L T (2000) Tritanopic color matches and the middle- and long-wavelength-sensitive cone spectral sensitivities. Vision Res 40:1739-50
Sharpe, L T; Stockman, A; Jagle, H et al. (1999) L, M and L-M hybrid cone photopigments in man: deriving lambda max from flicker photometric spectral sensitivities. Vision Res 39:3513-25
Stockman, A; Sharpe, L T; Fach, C (1999) The spectral sensitivity of the human short-wavelength sensitive cones derived from thresholds and color matches. Vision Res 39:2901-27
Stockman, A; Plummer, D J (1998) Color from invisible flicker: a failure of the Talbot-Plateau law caused by an early 'hard' saturating nonlinearity used to partition the human short-wave cone pathway. Vision Res 38:3703-28

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