A series of experiments is proposed that will use various non-linearities revealed by time-varying visual stimuli to analyze the human visual pathway. When an input signal passes through a non-linear site, new signal components are produced that were not present at its input. By carefully manipulating the visual stimuli that provide the input signal to the non-linearity, it is possible to distinguish the temporal properties of the visual pathways before and after each non-linear site. Three non-linearities will be studied. Each causes a burst of flicker to be perceived differently from a steady light of the same time-averaged intensity and chromaticity. The first, a compressive non-linearity, causes S-cone detected flicker to change in color; the second, also a compressive non-linearity, causes bursts of M- of L-cone detected flicker to change in color and saturation; and the third, an expansive non- linearity, causes bursts of M- or L-cone detected flicker to increase in apparent brightness. The primary aim of the proposed experiments is to use each non-linearity to dissect the early visual pathway. In some experiments, the non-linearity will be used as a recording electrode -- to measure the temporal frequency response of the visual system before the non-linearity; and in others it will be used as a stimulating electrode -- to measure the temporal frequency response of the visual system after the non-linearity. Preliminary evidence suggests that the temporal frequency response after each compressive non-linearity is characteristic of a chromatic pathway, while the response before each compressive non-linearity may more closely reflect the temporal frequency response of the receptors that the results of conventional temporal sensitivity measurements. It is proposed that the expansive non- linearity that affects M- and L-cone flicker is in a separate luminance pathway. The results of the proposed experiments will provide new insights into the postreceptoral organization of the visual system. Each non-linear site can provide a landmark at which psychophysical and physiological results can be compared. In the long-term, these experiments also may have important clinical implications, since it will be possible to use each non-linear site to localize and damage or deterioration that results from degenerative disease.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY010206-02
Application #
2163917
Study Section
Visual Sciences B Study Section (VISB)
Project Start
1993-07-01
Project End
1998-06-30
Budget Start
1994-07-01
Budget End
1995-06-30
Support Year
2
Fiscal Year
1994
Total Cost
Indirect Cost
Name
University of California San Diego
Department
Miscellaneous
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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