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Chromatic contrast detection in spatial chromatic noise

  • GIANLUCA MONACI (a1), GLORIA MENEGAZ (a2), SABINE SÜSSTRUNK (a3) and KENNETH KNOBLAUCH (a4)

Abstract

The spectral properties of chromatic-detection mechanisms were investigated using a noise-masking paradigm. Contrast-detection thresholds were measured for a signal with a Gaussian spatial profile, modulated in the equiluminant plane in the presence of spatial chromatic noise. The noise was distributed within a sector in the equiluminant plane, centered on the signal direction. Each stimulus consisted of two adjacent fields, one of which contained the signal, separated horizontally by a gap with the same average chromaticity as the uniform background. Observers were asked to judge on which side of the central fixation point the signal was displayed via a two-alternative, forced-choice (2AFC) paradigm. Contrast thresholds were measured for four color directions and three sector widths at increasing levels of the average energy of the axial component of the noise. Results show that contrast thresholds are unaffected by the width of the noise sector, as previously found for temporally modulated stimuli (D'Zmura & Knoblauch, 1998). The results are consistent with the existence of spectrally broadband linear-detection mechanisms tuned to the signal color direction and support the hypothesis of the existence of higher-order color mechanisms with sensitivities tuned to intermediate directions in color space.

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Corresponding author

Address correspondence and reprint requests to: Gianluca Monaci, Signal Processing Laboratory, Swiss Federal Institute of Technology, CH-1015 Lausanne, Switzerland. E-mail: Gianluca.Monaci@epfl.ch

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REFERENCES

Brainard, D.H. (1996). Cone contrast and opponent modulation color spaces. In Human Color Vision, ed. Kaiser, P. & Boynton, R.M., pp. 563579. Washington, DC: Optical Society of America.
Cardinal, K.S. & Kiper, D.C. (2003). The detection of colored glass patterns. Journal of Vision 3(3), 199208, http://www.journalofvision.org/3/3/2/.
Derrington, A.M., Krauskopf, J., & Lennie, P. (1984). Chromatic mechanisms in lateral geniculate nucleus of macaque. Journal of Physiology (London) 357, 241265.
Dobson, A.J. (1990). An Introduction to Generalized Linear Models. London, UK: Chapman & Hall.
D'Zmura, M. (1991). Color in visual search. Vision Research 31, 951966.
D'Zmura, M. & Knoblauch, K. (1998). Spectral bandwidth for the detection of color. Vision Research 38, 31173128.
Eskew, R.T., Jr., Newton, J.R., & Giulianini, F. (2001). Chromatic detection and discrimination analyzed by a Bayesian classifier. Vision Research 41, 893909.
Gegenfurtner, K.R. & Kiper, D.C. (1992). Contrast detection in luminance and chromatic noise. Journal of Optical Society of America A 9, 18801888.
Giulianini, F. & Eskew, R.T., Jr. (1998). Chromatic masking in the (ΔL/L, ΔM/M) plane of cone-contrast space reveals only two detection mechanisms. Vision Research 38, 39133926.
Goda, N. & Fuji, M. (2001). Sensitivity to modulation of color distribution in multicolored textures. Vision Research 41, 24752485.
Legge, G.E., Kersten, D., & Burgess, A.E. (1987). Contrast discrimination in noise. Journal of Optical Society of America A 4, 391404.
Lennie, P., Krauskopf, J., & Sclar G. (1990). Chromatic mechanisms in striate cortex of macaque. Journal of Neuroscience 10, 649669.
Kiper, D.C., Fenstemaker, S.B., & Gegenfurtner, K.R. (1997). Chromatic properties of neurons in macaque area V2. Visual Neuroscience 14, 10611072.
Krauskopf, J., Williams, D.R., Mandler, M.B., & Brown, A.M. (1986). Higher order color mechanisms. Vision Research 26, 2332.

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