Hostname: page-component-74656f9884-2dmjx Total loading time: 0 Render date: 2026-11-09T20:13:56.417Z Has data issue: false hasContentIssue false
  • English
  • Français

Chromatic contrast detection in spatial chromatic noise

Published online by Cambridge University Press:  05 April 2005

GIANLUCA MONACI ,
GLORIA MENEGAZ ,
SABINE SÜSSTRUNK  and
KENNETH KNOBLAUCH
GIANLUCA MONACI
Affiliation:
Signal Processing Laboratory, Swiss Federal Institute of Technology, Lausanne, Switzerland
GLORIA MENEGAZ
Affiliation:
Department of Information Engineering, School of Engineering, University of Siena, Italy
SABINE SÜSSTRUNK
Affiliation:
Audiovisual Communications Laboratory, Swiss Federal Institute of Technology, Lausanne, Switzerland
KENNETH KNOBLAUCH
Affiliation:
INSERM U371, Cerveau et Vision, IFR 19, Institut Fédératif des Neurosciences, Université Claude Bernard Lyon I, Bron cedex, France
Get access Rights & Permissions [Opens in a new window]

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.

Keywords

Chromatic discriminationNoiseSpectral bandwidthMasking

Information

Type
Research Article
Information
Visual Neuroscience , Volume 21 , Issue 3 , May 2004 , pp. 291 - 294
Copyright
© 2004 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable

References

REFERENCES

Brainard, D.H. (1996). Cone contrast and opponent modulation color spaces. In Human Color Vision, ed. Kaiser, P. & Boynton, R.M., pp. 563–579. Washington, DC: Optical Society of America.
Cardinal, K.S. & Kiper, D.C. (2003). The detection of colored glass patterns. Journal of Vision 3(3), 199–208, http://www.journalofvision.org/3/3/2/.Google Scholar
Derrington, A.M., Krauskopf, J., & Lennie, P. (1984). Chromatic mechanisms in lateral geniculate nucleus of macaque. Journal of Physiology (London) 357, 241–265.Google Scholar
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, 951–966.Google Scholar
D'Zmura, M. & Knoblauch, K. (1998). Spectral bandwidth for the detection of color. Vision Research 38, 3117–3128.Google Scholar
Eskew, R.T., Jr., Newton, J.R., & Giulianini, F. (2001). Chromatic detection and discrimination analyzed by a Bayesian classifier. Vision Research 41, 893–909.Google Scholar
Gegenfurtner, K.R. & Kiper, D.C. (1992). Contrast detection in luminance and chromatic noise. Journal of Optical Society of America A 9, 1880–1888.Google Scholar
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, 3913–3926.Google Scholar
Goda, N. & Fuji, M. (2001). Sensitivity to modulation of color distribution in multicolored textures. Vision Research 41, 2475–2485.Google Scholar
Legge, G.E., Kersten, D., & Burgess, A.E. (1987). Contrast discrimination in noise. Journal of Optical Society of America A 4, 391–404.Google Scholar
Lennie, P., Krauskopf, J., & Sclar G. (1990). Chromatic mechanisms in striate cortex of macaque. Journal of Neuroscience 10, 649–669.Google Scholar
Kiper, D.C., Fenstemaker, S.B., & Gegenfurtner, K.R. (1997). Chromatic properties of neurons in macaque area V2. Visual Neuroscience 14, 1061–1072.Google Scholar
Krauskopf, J., Williams, D.R., Mandler, M.B., & Brown, A.M. (1986). Higher order color mechanisms. Vision Research 26, 23–32.Google Scholar