Abstract

Significant orthogonal masking for color stimuli [Invest. Ophthalmol. Visual Sci. 34, 782 (No. 405-54) (1993)] but not for achromatic stimuli [J. Opt. Soc. Am. A 1, 226 (1984)] under sustained presentation led us to investigate the orientation tuning of the spatial-frequency- (SF-) tuned color mechanisms. The Red–Green channel was isolated from the achromatic channel by the minimum flicker technique and from the Yellow–Blue channel by the hue cancellation technique. Contrast sensitivity functions, threshold elevation versus mask orientation curves (measured by orientation masking), and threshold elevation versus mask contrast curves were measured by the method of constant stimuli and a two-interval forced-choice technique on two normal observers. Test targets were spatially localized (D6), vertical color patterns, and masks were sinusoidal color patterns oriented 15°–90° from the vertical in 15° steps and had the same SF's as those of test patterns. Mask contrasts were varied between 1.2% and 60%. The orientation tuning curves of the SF-tuned color mechanisms were extracted by obtaining the best fit to contrast sensitivity and threshold elevation data simultaneously at a given SF with use of the masking model. Results show that threshold elevations depend on test SF, mask SF, mask orientation, and mask contrast. Half-bandwidths at half-height (with respect to 15° from the vertical) of threshold elevation versus mask orientation curves range from 90° to 29° depending on SF's. The slopes of threshold elevation versus mask contrast curves range from 0.76 to 0.29 on octave–octave coordinates depending on SF's. Orientation half-bandwidths at half-height of orientation tuning curves of the SF-tuned color mechanisms (1) range from 79° to 28° and (2) average from 68° to 30° for SF's 0.063–8 cycles per degree (cpd). Data suggest that the orientation tuning curves of the SF-tuned chromatic mechanisms are broader (except at 2 cpd) than those of the achromatic mechanisms (orientation half-bandwidths: 32°–15° for 0.5–11.3 cpd [J. Opt. Soc. Am. A 1, 226 (1984)]); moreover, the orientation bandwidths are SF dependent.

© 1997 Optical Society of America

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References

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  1. G. C. Phillips, H. R. Wilson, “Orientation bandwidths of spatial mechanisms measured by masking,” J. Opt. Soc. Am. A 1, 226–232 (1984).
    [Crossref] [PubMed]
  2. R. L. DeValois, “Orientation and spatial frequency selectivity: properties and modular organization,” in From Pigments to Perception, A. Valberg, B. B. Lee, eds. (Plenum, New York, 1991), pp. 261–267.
  3. M. A. Webster, R. L. De Valois, “Relationship between spatial-frequency and orientation tuning of striate-cortexcells,” J. Opt. Soc. Am. A 2, 1124–1132 (1985);J. G. Daugman, “Two-dimensional spectral analysis of cortical receptive field profile,” Vision Res. 20, 847–856 (1980).
    [Crossref] [PubMed]
  4. R. Pandey, R. L. P. Vimal, “Threshold elevation curves for the Red–Greenchannel estimated by oblique masking,” Invest. Ophthalmol. Visual Sci. Suppl. 34, 751 (1993); R. L. P. Vimal, R. Pandey, “Spatial frequencytuned mechanisms of the Red–Green channel estimated by oblique masking,” Soc. Neurosci. Abstr. 20 (Part 2) 1580 (1994). For the achromatizing lens see I. Powell, “Lenses for correcting chromatic aberration of the eye,” Appl. Opt. 20, 4152–4155 (1981). For the hue cancellation technique, see D. Jameson, L. M. Hurvich, “Some quantitative aspects of an opponent-color theory. I. Chromaticresponses and spectral saturation,” J. Opt. Soc. Am. 45, 546–552 (1955). For the reddish–greenish cardinal axis, see J. Krauskopf, D. R. Williams, D. W. Heeley, “Cardinal directions of colour space,” Vision Res. 22, 1123–1131 (1982). For a Gaussian along the y axis, see R. W. Bowen, H. R. Wilson, “A two-process analysis of pattern masking,” Vision Res. 34, 645–657 (1994), and R. W. Bowen, “Isolation and interaction of ON and OFF pathways in human vision: contrastdiscrimination at pattern offset,” Vision Res. 37, 185–198 (1997). For contrasts see P. Lennie, M. D'Zmura, “Mechanisms of color vision,” CRC Crit. Rev. Neurobiol. 3, 333–400 (1988).
    [Crossref] [PubMed]
  5. H. R. Wilson, D. K. McFarlane, G. C. Phillips, “Spatial frequency tuning of orientation selective units estimated byoblique masking,” Vision Res. 23, 873–882 (1983).
    [Crossref]
  6. R. Pandey, R. L. P. Vimal, “Threshold elevation curves for low spatial frequencyflickering stimuli by oblique and horizontal masking techniques: chromaticand achromatic modes compared,” Invest. Ophthalmol. Visual Sci. Suppl. 33, 704 (1992); R. L. P. Vimal, R. Pandey, “In search of a spatial low-pass mechanism for sustained chromatic contrast sensitivity function by masking,” Invest. Ophthalmol. Visual Sci. Suppl. 33, 704 (1992).
  7. A. Bradley, E. Switkes, K. K. De Valois, “Orientation and spatial frequency selectivity of adaptation to colorand luminance gratings,” Vision Res. 28, 841–856 (1988).
    [Crossref]
  8. For a Gaussian fit to sine-wave masking data, see M. A. Losada, K. T. Mullen, “The spatial tuning of chromatic mechanisms identified by simultaneousmasking,” Vision Res. 34, 331–334 (1994). For an asymmetric exponential fit to sine-wave masking data and fornoise masking, see M. A. Losada, K. T. Mullen, “Color and luminance spatial tuning estimated by noise masking in theabsence of off-frequency looking,” J. Opt. Soc. Am. A 12, 250–260 (1995).
    [Crossref] [PubMed]
  9. M. A. Webster, K. K. De Valois, E. Switkes, “Orientation and spatial-frequency discrimination for luminance andchromatic gratings,” J. Opt. Soc. Am. A 7, 1034–1049. See also Ref. 24.
  10. R. L. P. Vimal, R. Pandey, “Measurement of peak spatial frequency and bandwidth of threshold elevationcurves of non-oriented units of the Red–Green channel by horizontalmasking,” Invest. Ophthalmol. Visual Sci. 34, 782 (1993).
  11. K. T. Mullen, “The contrast sensitivity of human color vision to red–green andblue–yellow chromatic gratings,” J. Physiol. (London) 359, 381–400 (1985), and references therein. For more reports on color CSF, see D. H. Kelly, “Spatiotemporal variation of chromatic and achromatic contrast threshold,” J. Opt. Soc. Am. 73, 742–750 (1983);E. M. Granger, J. C. Heurtley, “Visual chromaticity modulation transfer function,” J. Opt. Soc. Am. 63, 73–74 (1973);G. J. C. Van der Horst, C. M. M. DeWeert, M. A. Bouman, “Transfer of spatial chromaticity contrast at threshold in the humaneye,” J. Opt. Soc. Am. 57, 1260–1266 (1967).
    [Crossref] [PubMed]
  12. C. Blakemore, F. W. Campbell, “On the existence of neurons in the human visual system selectivelysensitive to the orientation and size of retinal images,” J. Physiol. (London) 203, 237–260 (1969).
  13. L. G. Thorell, R. L. De Valois, D. G. Albrecht, “Spatial mapping of monkey V1 cells with pure color and luminance stimuli,” Vision Res. 24, 751–769 (1984).
    [Crossref] [PubMed]
  14. R. L. P. Vimal, R. Pandey, “Orientation bandwidths of spatial frequency mechanism of the Red–Green channel estimated by masking,” in OSA Annual Meeting, Vol. 16 of 1993 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1993), p. 129.
  15. H. R. Wilson, “A transducer function for threshold and suprathreshold human vision,” Biol. Cybern. 38, 171–178 (1980).
    [Crossref] [PubMed]
  16. R. L. P. Vimal, J. M. Pokorny, V. C. Smith, S. K. Shevell, “Foveal cone thresholds,” Vision Res. 29, 61–78 (1989).
    [Crossref] [PubMed]
  17. stepit is a subroutine in J. P. Chandler, “stepit: direct research optimization solution of least-squares problems,” QCPE 11, 307 (1976), and J. P. Chandler, “stepit: direct search psychophysical model forpredicting the visibility of displayed information,” Proc. Soc. Inf. Disp. 21, 229–246 (1976).
  18. R. Bolt, L. Beranek, E. Newman, Curve Fitting Commands: RS/Explore User's Guide (BBN Research System, Cambridge, Mass., 1986), Book 3, pp. 9-1–9-6.
  19. J. Welkowitz, R. B. Ewen, J. Cohen, Introductory Statistics for the Behavioral Sciences (Academic, New York, 1976), pp. 304–307.
  20. V. C. Smith, R. W. Bowen, J. Pokorny, “Threshold temporal integration of chromatic stimuli,” Vision Res. 24, 653–660 (1984).
    [Crossref] [PubMed]
  21. K. T. Mullen, M. A. Losada, “Evidence for separate pathways for color and luminance detection mechanisms,” J. Opt. Soc. Am. A 11, 3136–3151 (1994).
    [Crossref]
  22. A. Elsner, “Hue difference contours can be used in processing orientation information,” Percept. Psychophys. 24, 451–456 (1978).
    [Crossref] [PubMed]
  23. P. Flanagan, P. Cavanagh, O. E. Favreau, “Independent orientation-selective mechanisms for the cardinal directionof color space,” Vision Res. 30, 769–778 (1990).
    [Crossref]
  24. R. L. P. Vimal, “Spatial frequency discriminations: inphase and counter-phase photopic conditions compared,” Invest. Ophthalmol. Visual Sci. Suppl. 29, 448 (1988).
  25. D. Y. Ts'o, C. D. Gilbert, “The organization of chromatic and spatial interaction in the primatestriate cortex,” J. Neurosci. 8, 1712–1727 (1988).
    [PubMed]
  26. B. M. Dow, P. Gouras, “Color and spatial specificity of single units in the rhesus monkeyfoveal striate cortex,” J. Neurophysiol. 36, 79–100 (1973).
    [PubMed]
  27. N. W. Daw, “The psychology and physiology of colour vision,” Trends Neurosci. 7, 330–335 (1984).
    [Crossref]
  28. M. S. Livingstone, D. H. Hubel, “Anatomy and physiology of color system in the primate visual cortex,” J. Neurosci. 4, 309–356 (1984);M. S. Livingstone, D. H. Hubel, “Psychophysical evidence for separate channels for the perception ofform, color, movement and depth,” J. Neurosci. 7, 3416–3468 (1987) .
    [PubMed]
  29. R. G. Vautin, B. M. Dow, “Color cell groups in foveal striate cortex of the behaving macaque,” J. Neurophysiol. 54, 273–292 (1985).
    [PubMed]
  30. P. Lennie, J. Krauskopf, G. Sclar, “Chromatic mechanisms in striate cortex of macaque,” J. Neurosci. 10, 649–669 (1990).
    [PubMed]
  31. C. R. Michael, “Laminar segregation of color cells in the monkey's striate cortex,” Vision Res. 25, 415–423 (1985).
    [Crossref] [PubMed]
  32. P. H. Schiller, B. L. Finlay, S. F. Volman, “Quantitative studies of single-cell properties in monkey striate cortex.II. Orientation specificity and ocular dominance,” J. Neurophysiol. 39, 1320–1333 (1976).
    [PubMed]
  33. A. M. Derrington, P. Lennie, “Spatial and temporal contrast sensitivities of neurons in lateral geniculatenucleus of macaque,” J. Physiol. (London) 357, 210–240 (1984); T. N. Wiesel, D. H. Hubel, “Spatial and chromatic interactions in the lateral geniculate body ofthe rhesus monkey,” J. Neurophysiol. 29, 1115–1156 (1966).
    [PubMed]
  34. V. P. Ferrera, H. R. Wilson, “Spatial frequency tuning of transient non-oriented units,” Vision Res. 25, 67–72 (1984).
    [Crossref]
  35. A. M. Sillito, J. A. Kemp, J. A. Milson, N. Berardi, “A re-evaluation of the mechanism underlying simple cell orientationselectivity,” Brain Res. 194, 517–520 (1980);J. D. Allison, V. A. Casagrande, A. B. Bonds, “The influence of input from the lower cortical layers on the orientation tuning of upper layer V1 cells in a primate,” Visual Neurosci. 12, 309–320 (1995).
    [Crossref] [PubMed]
  36. J. M. Foley, “Human luminance pattern-vision mechanisms: masking experiments requirea new model,” J. Opt. Soc. Am. A 11, 1710–1719 (1994);A. B. Bonds, “Role of inhibition in the specificationof orientation selectivity of cells in the cat striate cortex,” Visual Neurosci. 2, 41–55 (1989); D. J. Heeger, “Normalization of cell responsesin cat visual cortex,” Visual Neurosci. 9, 181–197 (1992), and references therein.
    [Crossref]

1994 (3)

For a Gaussian fit to sine-wave masking data, see M. A. Losada, K. T. Mullen, “The spatial tuning of chromatic mechanisms identified by simultaneousmasking,” Vision Res. 34, 331–334 (1994). For an asymmetric exponential fit to sine-wave masking data and fornoise masking, see M. A. Losada, K. T. Mullen, “Color and luminance spatial tuning estimated by noise masking in theabsence of off-frequency looking,” J. Opt. Soc. Am. A 12, 250–260 (1995).
[Crossref] [PubMed]

K. T. Mullen, M. A. Losada, “Evidence for separate pathways for color and luminance detection mechanisms,” J. Opt. Soc. Am. A 11, 3136–3151 (1994).
[Crossref]

J. M. Foley, “Human luminance pattern-vision mechanisms: masking experiments requirea new model,” J. Opt. Soc. Am. A 11, 1710–1719 (1994);A. B. Bonds, “Role of inhibition in the specificationof orientation selectivity of cells in the cat striate cortex,” Visual Neurosci. 2, 41–55 (1989); D. J. Heeger, “Normalization of cell responsesin cat visual cortex,” Visual Neurosci. 9, 181–197 (1992), and references therein.
[Crossref]

1993 (2)

R. L. P. Vimal, R. Pandey, “Measurement of peak spatial frequency and bandwidth of threshold elevationcurves of non-oriented units of the Red–Green channel by horizontalmasking,” Invest. Ophthalmol. Visual Sci. 34, 782 (1993).

R. Pandey, R. L. P. Vimal, “Threshold elevation curves for the Red–Greenchannel estimated by oblique masking,” Invest. Ophthalmol. Visual Sci. Suppl. 34, 751 (1993); R. L. P. Vimal, R. Pandey, “Spatial frequencytuned mechanisms of the Red–Green channel estimated by oblique masking,” Soc. Neurosci. Abstr. 20 (Part 2) 1580 (1994). For the achromatizing lens see I. Powell, “Lenses for correcting chromatic aberration of the eye,” Appl. Opt. 20, 4152–4155 (1981). For the hue cancellation technique, see D. Jameson, L. M. Hurvich, “Some quantitative aspects of an opponent-color theory. I. Chromaticresponses and spectral saturation,” J. Opt. Soc. Am. 45, 546–552 (1955). For the reddish–greenish cardinal axis, see J. Krauskopf, D. R. Williams, D. W. Heeley, “Cardinal directions of colour space,” Vision Res. 22, 1123–1131 (1982). For a Gaussian along the y axis, see R. W. Bowen, H. R. Wilson, “A two-process analysis of pattern masking,” Vision Res. 34, 645–657 (1994), and R. W. Bowen, “Isolation and interaction of ON and OFF pathways in human vision: contrastdiscrimination at pattern offset,” Vision Res. 37, 185–198 (1997). For contrasts see P. Lennie, M. D'Zmura, “Mechanisms of color vision,” CRC Crit. Rev. Neurobiol. 3, 333–400 (1988).
[Crossref] [PubMed]

1992 (1)

R. Pandey, R. L. P. Vimal, “Threshold elevation curves for low spatial frequencyflickering stimuli by oblique and horizontal masking techniques: chromaticand achromatic modes compared,” Invest. Ophthalmol. Visual Sci. Suppl. 33, 704 (1992); R. L. P. Vimal, R. Pandey, “In search of a spatial low-pass mechanism for sustained chromatic contrast sensitivity function by masking,” Invest. Ophthalmol. Visual Sci. Suppl. 33, 704 (1992).

1990 (2)

P. Lennie, J. Krauskopf, G. Sclar, “Chromatic mechanisms in striate cortex of macaque,” J. Neurosci. 10, 649–669 (1990).
[PubMed]

P. Flanagan, P. Cavanagh, O. E. Favreau, “Independent orientation-selective mechanisms for the cardinal directionof color space,” Vision Res. 30, 769–778 (1990).
[Crossref]

1989 (1)

R. L. P. Vimal, J. M. Pokorny, V. C. Smith, S. K. Shevell, “Foveal cone thresholds,” Vision Res. 29, 61–78 (1989).
[Crossref] [PubMed]

1988 (3)

A. Bradley, E. Switkes, K. K. De Valois, “Orientation and spatial frequency selectivity of adaptation to colorand luminance gratings,” Vision Res. 28, 841–856 (1988).
[Crossref]

R. L. P. Vimal, “Spatial frequency discriminations: inphase and counter-phase photopic conditions compared,” Invest. Ophthalmol. Visual Sci. Suppl. 29, 448 (1988).

D. Y. Ts'o, C. D. Gilbert, “The organization of chromatic and spatial interaction in the primatestriate cortex,” J. Neurosci. 8, 1712–1727 (1988).
[PubMed]

1985 (4)

R. G. Vautin, B. M. Dow, “Color cell groups in foveal striate cortex of the behaving macaque,” J. Neurophysiol. 54, 273–292 (1985).
[PubMed]

C. R. Michael, “Laminar segregation of color cells in the monkey's striate cortex,” Vision Res. 25, 415–423 (1985).
[Crossref] [PubMed]

M. A. Webster, R. L. De Valois, “Relationship between spatial-frequency and orientation tuning of striate-cortexcells,” J. Opt. Soc. Am. A 2, 1124–1132 (1985);J. G. Daugman, “Two-dimensional spectral analysis of cortical receptive field profile,” Vision Res. 20, 847–856 (1980).
[Crossref] [PubMed]

K. T. Mullen, “The contrast sensitivity of human color vision to red–green andblue–yellow chromatic gratings,” J. Physiol. (London) 359, 381–400 (1985), and references therein. For more reports on color CSF, see D. H. Kelly, “Spatiotemporal variation of chromatic and achromatic contrast threshold,” J. Opt. Soc. Am. 73, 742–750 (1983);E. M. Granger, J. C. Heurtley, “Visual chromaticity modulation transfer function,” J. Opt. Soc. Am. 63, 73–74 (1973);G. J. C. Van der Horst, C. M. M. DeWeert, M. A. Bouman, “Transfer of spatial chromaticity contrast at threshold in the humaneye,” J. Opt. Soc. Am. 57, 1260–1266 (1967).
[Crossref] [PubMed]

1984 (7)

G. C. Phillips, H. R. Wilson, “Orientation bandwidths of spatial mechanisms measured by masking,” J. Opt. Soc. Am. A 1, 226–232 (1984).
[Crossref] [PubMed]

L. G. Thorell, R. L. De Valois, D. G. Albrecht, “Spatial mapping of monkey V1 cells with pure color and luminance stimuli,” Vision Res. 24, 751–769 (1984).
[Crossref] [PubMed]

A. M. Derrington, P. Lennie, “Spatial and temporal contrast sensitivities of neurons in lateral geniculatenucleus of macaque,” J. Physiol. (London) 357, 210–240 (1984); T. N. Wiesel, D. H. Hubel, “Spatial and chromatic interactions in the lateral geniculate body ofthe rhesus monkey,” J. Neurophysiol. 29, 1115–1156 (1966).
[PubMed]

V. P. Ferrera, H. R. Wilson, “Spatial frequency tuning of transient non-oriented units,” Vision Res. 25, 67–72 (1984).
[Crossref]

V. C. Smith, R. W. Bowen, J. Pokorny, “Threshold temporal integration of chromatic stimuli,” Vision Res. 24, 653–660 (1984).
[Crossref] [PubMed]

N. W. Daw, “The psychology and physiology of colour vision,” Trends Neurosci. 7, 330–335 (1984).
[Crossref]

M. S. Livingstone, D. H. Hubel, “Anatomy and physiology of color system in the primate visual cortex,” J. Neurosci. 4, 309–356 (1984);M. S. Livingstone, D. H. Hubel, “Psychophysical evidence for separate channels for the perception ofform, color, movement and depth,” J. Neurosci. 7, 3416–3468 (1987) .
[PubMed]

1983 (1)

H. R. Wilson, D. K. McFarlane, G. C. Phillips, “Spatial frequency tuning of orientation selective units estimated byoblique masking,” Vision Res. 23, 873–882 (1983).
[Crossref]

1980 (2)

H. R. Wilson, “A transducer function for threshold and suprathreshold human vision,” Biol. Cybern. 38, 171–178 (1980).
[Crossref] [PubMed]

A. M. Sillito, J. A. Kemp, J. A. Milson, N. Berardi, “A re-evaluation of the mechanism underlying simple cell orientationselectivity,” Brain Res. 194, 517–520 (1980);J. D. Allison, V. A. Casagrande, A. B. Bonds, “The influence of input from the lower cortical layers on the orientation tuning of upper layer V1 cells in a primate,” Visual Neurosci. 12, 309–320 (1995).
[Crossref] [PubMed]

1978 (1)

A. Elsner, “Hue difference contours can be used in processing orientation information,” Percept. Psychophys. 24, 451–456 (1978).
[Crossref] [PubMed]

1976 (2)

stepit is a subroutine in J. P. Chandler, “stepit: direct research optimization solution of least-squares problems,” QCPE 11, 307 (1976), and J. P. Chandler, “stepit: direct search psychophysical model forpredicting the visibility of displayed information,” Proc. Soc. Inf. Disp. 21, 229–246 (1976).

P. H. Schiller, B. L. Finlay, S. F. Volman, “Quantitative studies of single-cell properties in monkey striate cortex.II. Orientation specificity and ocular dominance,” J. Neurophysiol. 39, 1320–1333 (1976).
[PubMed]

1973 (1)

B. M. Dow, P. Gouras, “Color and spatial specificity of single units in the rhesus monkeyfoveal striate cortex,” J. Neurophysiol. 36, 79–100 (1973).
[PubMed]

1969 (1)

C. Blakemore, F. W. Campbell, “On the existence of neurons in the human visual system selectivelysensitive to the orientation and size of retinal images,” J. Physiol. (London) 203, 237–260 (1969).

Albrecht, D. G.

L. G. Thorell, R. L. De Valois, D. G. Albrecht, “Spatial mapping of monkey V1 cells with pure color and luminance stimuli,” Vision Res. 24, 751–769 (1984).
[Crossref] [PubMed]

Beranek, L.

R. Bolt, L. Beranek, E. Newman, Curve Fitting Commands: RS/Explore User's Guide (BBN Research System, Cambridge, Mass., 1986), Book 3, pp. 9-1–9-6.

Berardi, N.

A. M. Sillito, J. A. Kemp, J. A. Milson, N. Berardi, “A re-evaluation of the mechanism underlying simple cell orientationselectivity,” Brain Res. 194, 517–520 (1980);J. D. Allison, V. A. Casagrande, A. B. Bonds, “The influence of input from the lower cortical layers on the orientation tuning of upper layer V1 cells in a primate,” Visual Neurosci. 12, 309–320 (1995).
[Crossref] [PubMed]

Blakemore, C.

C. Blakemore, F. W. Campbell, “On the existence of neurons in the human visual system selectivelysensitive to the orientation and size of retinal images,” J. Physiol. (London) 203, 237–260 (1969).

Bolt, R.

R. Bolt, L. Beranek, E. Newman, Curve Fitting Commands: RS/Explore User's Guide (BBN Research System, Cambridge, Mass., 1986), Book 3, pp. 9-1–9-6.

Bowen, R. W.

V. C. Smith, R. W. Bowen, J. Pokorny, “Threshold temporal integration of chromatic stimuli,” Vision Res. 24, 653–660 (1984).
[Crossref] [PubMed]

Bradley, A.

A. Bradley, E. Switkes, K. K. De Valois, “Orientation and spatial frequency selectivity of adaptation to colorand luminance gratings,” Vision Res. 28, 841–856 (1988).
[Crossref]

Campbell, F. W.

C. Blakemore, F. W. Campbell, “On the existence of neurons in the human visual system selectivelysensitive to the orientation and size of retinal images,” J. Physiol. (London) 203, 237–260 (1969).

Cavanagh, P.

P. Flanagan, P. Cavanagh, O. E. Favreau, “Independent orientation-selective mechanisms for the cardinal directionof color space,” Vision Res. 30, 769–778 (1990).
[Crossref]

Chandler, J. P.

stepit is a subroutine in J. P. Chandler, “stepit: direct research optimization solution of least-squares problems,” QCPE 11, 307 (1976), and J. P. Chandler, “stepit: direct search psychophysical model forpredicting the visibility of displayed information,” Proc. Soc. Inf. Disp. 21, 229–246 (1976).

Cohen, J.

J. Welkowitz, R. B. Ewen, J. Cohen, Introductory Statistics for the Behavioral Sciences (Academic, New York, 1976), pp. 304–307.

Daw, N. W.

N. W. Daw, “The psychology and physiology of colour vision,” Trends Neurosci. 7, 330–335 (1984).
[Crossref]

De Valois, K. K.

A. Bradley, E. Switkes, K. K. De Valois, “Orientation and spatial frequency selectivity of adaptation to colorand luminance gratings,” Vision Res. 28, 841–856 (1988).
[Crossref]

M. A. Webster, K. K. De Valois, E. Switkes, “Orientation and spatial-frequency discrimination for luminance andchromatic gratings,” J. Opt. Soc. Am. A 7, 1034–1049. See also Ref. 24.

De Valois, R. L.

Derrington, A. M.

A. M. Derrington, P. Lennie, “Spatial and temporal contrast sensitivities of neurons in lateral geniculatenucleus of macaque,” J. Physiol. (London) 357, 210–240 (1984); T. N. Wiesel, D. H. Hubel, “Spatial and chromatic interactions in the lateral geniculate body ofthe rhesus monkey,” J. Neurophysiol. 29, 1115–1156 (1966).
[PubMed]

DeValois, R. L.

R. L. DeValois, “Orientation and spatial frequency selectivity: properties and modular organization,” in From Pigments to Perception, A. Valberg, B. B. Lee, eds. (Plenum, New York, 1991), pp. 261–267.

Dow, B. M.

R. G. Vautin, B. M. Dow, “Color cell groups in foveal striate cortex of the behaving macaque,” J. Neurophysiol. 54, 273–292 (1985).
[PubMed]

B. M. Dow, P. Gouras, “Color and spatial specificity of single units in the rhesus monkeyfoveal striate cortex,” J. Neurophysiol. 36, 79–100 (1973).
[PubMed]

Elsner, A.

A. Elsner, “Hue difference contours can be used in processing orientation information,” Percept. Psychophys. 24, 451–456 (1978).
[Crossref] [PubMed]

Ewen, R. B.

J. Welkowitz, R. B. Ewen, J. Cohen, Introductory Statistics for the Behavioral Sciences (Academic, New York, 1976), pp. 304–307.

Favreau, O. E.

P. Flanagan, P. Cavanagh, O. E. Favreau, “Independent orientation-selective mechanisms for the cardinal directionof color space,” Vision Res. 30, 769–778 (1990).
[Crossref]

Ferrera, V. P.

V. P. Ferrera, H. R. Wilson, “Spatial frequency tuning of transient non-oriented units,” Vision Res. 25, 67–72 (1984).
[Crossref]

Finlay, B. L.

P. H. Schiller, B. L. Finlay, S. F. Volman, “Quantitative studies of single-cell properties in monkey striate cortex.II. Orientation specificity and ocular dominance,” J. Neurophysiol. 39, 1320–1333 (1976).
[PubMed]

Flanagan, P.

P. Flanagan, P. Cavanagh, O. E. Favreau, “Independent orientation-selective mechanisms for the cardinal directionof color space,” Vision Res. 30, 769–778 (1990).
[Crossref]

Foley, J. M.

Gilbert, C. D.

D. Y. Ts'o, C. D. Gilbert, “The organization of chromatic and spatial interaction in the primatestriate cortex,” J. Neurosci. 8, 1712–1727 (1988).
[PubMed]

Gouras, P.

B. M. Dow, P. Gouras, “Color and spatial specificity of single units in the rhesus monkeyfoveal striate cortex,” J. Neurophysiol. 36, 79–100 (1973).
[PubMed]

Hubel, D. H.

M. S. Livingstone, D. H. Hubel, “Anatomy and physiology of color system in the primate visual cortex,” J. Neurosci. 4, 309–356 (1984);M. S. Livingstone, D. H. Hubel, “Psychophysical evidence for separate channels for the perception ofform, color, movement and depth,” J. Neurosci. 7, 3416–3468 (1987) .
[PubMed]

Kemp, J. A.

A. M. Sillito, J. A. Kemp, J. A. Milson, N. Berardi, “A re-evaluation of the mechanism underlying simple cell orientationselectivity,” Brain Res. 194, 517–520 (1980);J. D. Allison, V. A. Casagrande, A. B. Bonds, “The influence of input from the lower cortical layers on the orientation tuning of upper layer V1 cells in a primate,” Visual Neurosci. 12, 309–320 (1995).
[Crossref] [PubMed]

Krauskopf, J.

P. Lennie, J. Krauskopf, G. Sclar, “Chromatic mechanisms in striate cortex of macaque,” J. Neurosci. 10, 649–669 (1990).
[PubMed]

Lennie, P.

P. Lennie, J. Krauskopf, G. Sclar, “Chromatic mechanisms in striate cortex of macaque,” J. Neurosci. 10, 649–669 (1990).
[PubMed]

A. M. Derrington, P. Lennie, “Spatial and temporal contrast sensitivities of neurons in lateral geniculatenucleus of macaque,” J. Physiol. (London) 357, 210–240 (1984); T. N. Wiesel, D. H. Hubel, “Spatial and chromatic interactions in the lateral geniculate body ofthe rhesus monkey,” J. Neurophysiol. 29, 1115–1156 (1966).
[PubMed]

Livingstone, M. S.

M. S. Livingstone, D. H. Hubel, “Anatomy and physiology of color system in the primate visual cortex,” J. Neurosci. 4, 309–356 (1984);M. S. Livingstone, D. H. Hubel, “Psychophysical evidence for separate channels for the perception ofform, color, movement and depth,” J. Neurosci. 7, 3416–3468 (1987) .
[PubMed]

Losada, M. A.

K. T. Mullen, M. A. Losada, “Evidence for separate pathways for color and luminance detection mechanisms,” J. Opt. Soc. Am. A 11, 3136–3151 (1994).
[Crossref]

For a Gaussian fit to sine-wave masking data, see M. A. Losada, K. T. Mullen, “The spatial tuning of chromatic mechanisms identified by simultaneousmasking,” Vision Res. 34, 331–334 (1994). For an asymmetric exponential fit to sine-wave masking data and fornoise masking, see M. A. Losada, K. T. Mullen, “Color and luminance spatial tuning estimated by noise masking in theabsence of off-frequency looking,” J. Opt. Soc. Am. A 12, 250–260 (1995).
[Crossref] [PubMed]

McFarlane, D. K.

H. R. Wilson, D. K. McFarlane, G. C. Phillips, “Spatial frequency tuning of orientation selective units estimated byoblique masking,” Vision Res. 23, 873–882 (1983).
[Crossref]

Michael, C. R.

C. R. Michael, “Laminar segregation of color cells in the monkey's striate cortex,” Vision Res. 25, 415–423 (1985).
[Crossref] [PubMed]

Milson, J. A.

A. M. Sillito, J. A. Kemp, J. A. Milson, N. Berardi, “A re-evaluation of the mechanism underlying simple cell orientationselectivity,” Brain Res. 194, 517–520 (1980);J. D. Allison, V. A. Casagrande, A. B. Bonds, “The influence of input from the lower cortical layers on the orientation tuning of upper layer V1 cells in a primate,” Visual Neurosci. 12, 309–320 (1995).
[Crossref] [PubMed]

Mullen, K. T.

K. T. Mullen, M. A. Losada, “Evidence for separate pathways for color and luminance detection mechanisms,” J. Opt. Soc. Am. A 11, 3136–3151 (1994).
[Crossref]

For a Gaussian fit to sine-wave masking data, see M. A. Losada, K. T. Mullen, “The spatial tuning of chromatic mechanisms identified by simultaneousmasking,” Vision Res. 34, 331–334 (1994). For an asymmetric exponential fit to sine-wave masking data and fornoise masking, see M. A. Losada, K. T. Mullen, “Color and luminance spatial tuning estimated by noise masking in theabsence of off-frequency looking,” J. Opt. Soc. Am. A 12, 250–260 (1995).
[Crossref] [PubMed]

K. T. Mullen, “The contrast sensitivity of human color vision to red–green andblue–yellow chromatic gratings,” J. Physiol. (London) 359, 381–400 (1985), and references therein. For more reports on color CSF, see D. H. Kelly, “Spatiotemporal variation of chromatic and achromatic contrast threshold,” J. Opt. Soc. Am. 73, 742–750 (1983);E. M. Granger, J. C. Heurtley, “Visual chromaticity modulation transfer function,” J. Opt. Soc. Am. 63, 73–74 (1973);G. J. C. Van der Horst, C. M. M. DeWeert, M. A. Bouman, “Transfer of spatial chromaticity contrast at threshold in the humaneye,” J. Opt. Soc. Am. 57, 1260–1266 (1967).
[Crossref] [PubMed]

Newman, E.

R. Bolt, L. Beranek, E. Newman, Curve Fitting Commands: RS/Explore User's Guide (BBN Research System, Cambridge, Mass., 1986), Book 3, pp. 9-1–9-6.

Pandey, R.

R. L. P. Vimal, R. Pandey, “Measurement of peak spatial frequency and bandwidth of threshold elevationcurves of non-oriented units of the Red–Green channel by horizontalmasking,” Invest. Ophthalmol. Visual Sci. 34, 782 (1993).

R. Pandey, R. L. P. Vimal, “Threshold elevation curves for the Red–Greenchannel estimated by oblique masking,” Invest. Ophthalmol. Visual Sci. Suppl. 34, 751 (1993); R. L. P. Vimal, R. Pandey, “Spatial frequencytuned mechanisms of the Red–Green channel estimated by oblique masking,” Soc. Neurosci. Abstr. 20 (Part 2) 1580 (1994). For the achromatizing lens see I. Powell, “Lenses for correcting chromatic aberration of the eye,” Appl. Opt. 20, 4152–4155 (1981). For the hue cancellation technique, see D. Jameson, L. M. Hurvich, “Some quantitative aspects of an opponent-color theory. I. Chromaticresponses and spectral saturation,” J. Opt. Soc. Am. 45, 546–552 (1955). For the reddish–greenish cardinal axis, see J. Krauskopf, D. R. Williams, D. W. Heeley, “Cardinal directions of colour space,” Vision Res. 22, 1123–1131 (1982). For a Gaussian along the y axis, see R. W. Bowen, H. R. Wilson, “A two-process analysis of pattern masking,” Vision Res. 34, 645–657 (1994), and R. W. Bowen, “Isolation and interaction of ON and OFF pathways in human vision: contrastdiscrimination at pattern offset,” Vision Res. 37, 185–198 (1997). For contrasts see P. Lennie, M. D'Zmura, “Mechanisms of color vision,” CRC Crit. Rev. Neurobiol. 3, 333–400 (1988).
[Crossref] [PubMed]

R. Pandey, R. L. P. Vimal, “Threshold elevation curves for low spatial frequencyflickering stimuli by oblique and horizontal masking techniques: chromaticand achromatic modes compared,” Invest. Ophthalmol. Visual Sci. Suppl. 33, 704 (1992); R. L. P. Vimal, R. Pandey, “In search of a spatial low-pass mechanism for sustained chromatic contrast sensitivity function by masking,” Invest. Ophthalmol. Visual Sci. Suppl. 33, 704 (1992).

R. L. P. Vimal, R. Pandey, “Orientation bandwidths of spatial frequency mechanism of the Red–Green channel estimated by masking,” in OSA Annual Meeting, Vol. 16 of 1993 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1993), p. 129.

Phillips, G. C.

G. C. Phillips, H. R. Wilson, “Orientation bandwidths of spatial mechanisms measured by masking,” J. Opt. Soc. Am. A 1, 226–232 (1984).
[Crossref] [PubMed]

H. R. Wilson, D. K. McFarlane, G. C. Phillips, “Spatial frequency tuning of orientation selective units estimated byoblique masking,” Vision Res. 23, 873–882 (1983).
[Crossref]

Pokorny, J.

V. C. Smith, R. W. Bowen, J. Pokorny, “Threshold temporal integration of chromatic stimuli,” Vision Res. 24, 653–660 (1984).
[Crossref] [PubMed]

Pokorny, J. M.

R. L. P. Vimal, J. M. Pokorny, V. C. Smith, S. K. Shevell, “Foveal cone thresholds,” Vision Res. 29, 61–78 (1989).
[Crossref] [PubMed]

Schiller, P. H.

P. H. Schiller, B. L. Finlay, S. F. Volman, “Quantitative studies of single-cell properties in monkey striate cortex.II. Orientation specificity and ocular dominance,” J. Neurophysiol. 39, 1320–1333 (1976).
[PubMed]

Sclar, G.

P. Lennie, J. Krauskopf, G. Sclar, “Chromatic mechanisms in striate cortex of macaque,” J. Neurosci. 10, 649–669 (1990).
[PubMed]

Shevell, S. K.

R. L. P. Vimal, J. M. Pokorny, V. C. Smith, S. K. Shevell, “Foveal cone thresholds,” Vision Res. 29, 61–78 (1989).
[Crossref] [PubMed]

Sillito, A. M.

A. M. Sillito, J. A. Kemp, J. A. Milson, N. Berardi, “A re-evaluation of the mechanism underlying simple cell orientationselectivity,” Brain Res. 194, 517–520 (1980);J. D. Allison, V. A. Casagrande, A. B. Bonds, “The influence of input from the lower cortical layers on the orientation tuning of upper layer V1 cells in a primate,” Visual Neurosci. 12, 309–320 (1995).
[Crossref] [PubMed]

Smith, V. C.

R. L. P. Vimal, J. M. Pokorny, V. C. Smith, S. K. Shevell, “Foveal cone thresholds,” Vision Res. 29, 61–78 (1989).
[Crossref] [PubMed]

V. C. Smith, R. W. Bowen, J. Pokorny, “Threshold temporal integration of chromatic stimuli,” Vision Res. 24, 653–660 (1984).
[Crossref] [PubMed]

Switkes, E.

A. Bradley, E. Switkes, K. K. De Valois, “Orientation and spatial frequency selectivity of adaptation to colorand luminance gratings,” Vision Res. 28, 841–856 (1988).
[Crossref]

M. A. Webster, K. K. De Valois, E. Switkes, “Orientation and spatial-frequency discrimination for luminance andchromatic gratings,” J. Opt. Soc. Am. A 7, 1034–1049. See also Ref. 24.

Thorell, L. G.

L. G. Thorell, R. L. De Valois, D. G. Albrecht, “Spatial mapping of monkey V1 cells with pure color and luminance stimuli,” Vision Res. 24, 751–769 (1984).
[Crossref] [PubMed]

Ts'o, D. Y.

D. Y. Ts'o, C. D. Gilbert, “The organization of chromatic and spatial interaction in the primatestriate cortex,” J. Neurosci. 8, 1712–1727 (1988).
[PubMed]

Vautin, R. G.

R. G. Vautin, B. M. Dow, “Color cell groups in foveal striate cortex of the behaving macaque,” J. Neurophysiol. 54, 273–292 (1985).
[PubMed]

Vimal, R. L. P.

R. L. P. Vimal, R. Pandey, “Measurement of peak spatial frequency and bandwidth of threshold elevationcurves of non-oriented units of the Red–Green channel by horizontalmasking,” Invest. Ophthalmol. Visual Sci. 34, 782 (1993).

R. Pandey, R. L. P. Vimal, “Threshold elevation curves for the Red–Greenchannel estimated by oblique masking,” Invest. Ophthalmol. Visual Sci. Suppl. 34, 751 (1993); R. L. P. Vimal, R. Pandey, “Spatial frequencytuned mechanisms of the Red–Green channel estimated by oblique masking,” Soc. Neurosci. Abstr. 20 (Part 2) 1580 (1994). For the achromatizing lens see I. Powell, “Lenses for correcting chromatic aberration of the eye,” Appl. Opt. 20, 4152–4155 (1981). For the hue cancellation technique, see D. Jameson, L. M. Hurvich, “Some quantitative aspects of an opponent-color theory. I. Chromaticresponses and spectral saturation,” J. Opt. Soc. Am. 45, 546–552 (1955). For the reddish–greenish cardinal axis, see J. Krauskopf, D. R. Williams, D. W. Heeley, “Cardinal directions of colour space,” Vision Res. 22, 1123–1131 (1982). For a Gaussian along the y axis, see R. W. Bowen, H. R. Wilson, “A two-process analysis of pattern masking,” Vision Res. 34, 645–657 (1994), and R. W. Bowen, “Isolation and interaction of ON and OFF pathways in human vision: contrastdiscrimination at pattern offset,” Vision Res. 37, 185–198 (1997). For contrasts see P. Lennie, M. D'Zmura, “Mechanisms of color vision,” CRC Crit. Rev. Neurobiol. 3, 333–400 (1988).
[Crossref] [PubMed]

R. Pandey, R. L. P. Vimal, “Threshold elevation curves for low spatial frequencyflickering stimuli by oblique and horizontal masking techniques: chromaticand achromatic modes compared,” Invest. Ophthalmol. Visual Sci. Suppl. 33, 704 (1992); R. L. P. Vimal, R. Pandey, “In search of a spatial low-pass mechanism for sustained chromatic contrast sensitivity function by masking,” Invest. Ophthalmol. Visual Sci. Suppl. 33, 704 (1992).

R. L. P. Vimal, J. M. Pokorny, V. C. Smith, S. K. Shevell, “Foveal cone thresholds,” Vision Res. 29, 61–78 (1989).
[Crossref] [PubMed]

R. L. P. Vimal, “Spatial frequency discriminations: inphase and counter-phase photopic conditions compared,” Invest. Ophthalmol. Visual Sci. Suppl. 29, 448 (1988).

R. L. P. Vimal, R. Pandey, “Orientation bandwidths of spatial frequency mechanism of the Red–Green channel estimated by masking,” in OSA Annual Meeting, Vol. 16 of 1993 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1993), p. 129.

Volman, S. F.

P. H. Schiller, B. L. Finlay, S. F. Volman, “Quantitative studies of single-cell properties in monkey striate cortex.II. Orientation specificity and ocular dominance,” J. Neurophysiol. 39, 1320–1333 (1976).
[PubMed]

Webster, M. A.

Welkowitz, J.

J. Welkowitz, R. B. Ewen, J. Cohen, Introductory Statistics for the Behavioral Sciences (Academic, New York, 1976), pp. 304–307.

Wilson, H. R.

G. C. Phillips, H. R. Wilson, “Orientation bandwidths of spatial mechanisms measured by masking,” J. Opt. Soc. Am. A 1, 226–232 (1984).
[Crossref] [PubMed]

V. P. Ferrera, H. R. Wilson, “Spatial frequency tuning of transient non-oriented units,” Vision Res. 25, 67–72 (1984).
[Crossref]

H. R. Wilson, D. K. McFarlane, G. C. Phillips, “Spatial frequency tuning of orientation selective units estimated byoblique masking,” Vision Res. 23, 873–882 (1983).
[Crossref]

H. R. Wilson, “A transducer function for threshold and suprathreshold human vision,” Biol. Cybern. 38, 171–178 (1980).
[Crossref] [PubMed]

Biol. Cybern. (1)

H. R. Wilson, “A transducer function for threshold and suprathreshold human vision,” Biol. Cybern. 38, 171–178 (1980).
[Crossref] [PubMed]

Brain Res. (1)

A. M. Sillito, J. A. Kemp, J. A. Milson, N. Berardi, “A re-evaluation of the mechanism underlying simple cell orientationselectivity,” Brain Res. 194, 517–520 (1980);J. D. Allison, V. A. Casagrande, A. B. Bonds, “The influence of input from the lower cortical layers on the orientation tuning of upper layer V1 cells in a primate,” Visual Neurosci. 12, 309–320 (1995).
[Crossref] [PubMed]

Invest. Ophthalmol. Visual Sci. (1)

R. L. P. Vimal, R. Pandey, “Measurement of peak spatial frequency and bandwidth of threshold elevationcurves of non-oriented units of the Red–Green channel by horizontalmasking,” Invest. Ophthalmol. Visual Sci. 34, 782 (1993).

Invest. Ophthalmol. Visual Sci. Suppl. (1)

R. Pandey, R. L. P. Vimal, “Threshold elevation curves for low spatial frequencyflickering stimuli by oblique and horizontal masking techniques: chromaticand achromatic modes compared,” Invest. Ophthalmol. Visual Sci. Suppl. 33, 704 (1992); R. L. P. Vimal, R. Pandey, “In search of a spatial low-pass mechanism for sustained chromatic contrast sensitivity function by masking,” Invest. Ophthalmol. Visual Sci. Suppl. 33, 704 (1992).

Invest. Ophthalmol. Visual Sci. Suppl. (2)

R. Pandey, R. L. P. Vimal, “Threshold elevation curves for the Red–Greenchannel estimated by oblique masking,” Invest. Ophthalmol. Visual Sci. Suppl. 34, 751 (1993); R. L. P. Vimal, R. Pandey, “Spatial frequencytuned mechanisms of the Red–Green channel estimated by oblique masking,” Soc. Neurosci. Abstr. 20 (Part 2) 1580 (1994). For the achromatizing lens see I. Powell, “Lenses for correcting chromatic aberration of the eye,” Appl. Opt. 20, 4152–4155 (1981). For the hue cancellation technique, see D. Jameson, L. M. Hurvich, “Some quantitative aspects of an opponent-color theory. I. Chromaticresponses and spectral saturation,” J. Opt. Soc. Am. 45, 546–552 (1955). For the reddish–greenish cardinal axis, see J. Krauskopf, D. R. Williams, D. W. Heeley, “Cardinal directions of colour space,” Vision Res. 22, 1123–1131 (1982). For a Gaussian along the y axis, see R. W. Bowen, H. R. Wilson, “A two-process analysis of pattern masking,” Vision Res. 34, 645–657 (1994), and R. W. Bowen, “Isolation and interaction of ON and OFF pathways in human vision: contrastdiscrimination at pattern offset,” Vision Res. 37, 185–198 (1997). For contrasts see P. Lennie, M. D'Zmura, “Mechanisms of color vision,” CRC Crit. Rev. Neurobiol. 3, 333–400 (1988).
[Crossref] [PubMed]

R. L. P. Vimal, “Spatial frequency discriminations: inphase and counter-phase photopic conditions compared,” Invest. Ophthalmol. Visual Sci. Suppl. 29, 448 (1988).

J. Neurophysiol. (3)

B. M. Dow, P. Gouras, “Color and spatial specificity of single units in the rhesus monkeyfoveal striate cortex,” J. Neurophysiol. 36, 79–100 (1973).
[PubMed]

R. G. Vautin, B. M. Dow, “Color cell groups in foveal striate cortex of the behaving macaque,” J. Neurophysiol. 54, 273–292 (1985).
[PubMed]

P. H. Schiller, B. L. Finlay, S. F. Volman, “Quantitative studies of single-cell properties in monkey striate cortex.II. Orientation specificity and ocular dominance,” J. Neurophysiol. 39, 1320–1333 (1976).
[PubMed]

J. Neurosci. (3)

P. Lennie, J. Krauskopf, G. Sclar, “Chromatic mechanisms in striate cortex of macaque,” J. Neurosci. 10, 649–669 (1990).
[PubMed]

M. S. Livingstone, D. H. Hubel, “Anatomy and physiology of color system in the primate visual cortex,” J. Neurosci. 4, 309–356 (1984);M. S. Livingstone, D. H. Hubel, “Psychophysical evidence for separate channels for the perception ofform, color, movement and depth,” J. Neurosci. 7, 3416–3468 (1987) .
[PubMed]

D. Y. Ts'o, C. D. Gilbert, “The organization of chromatic and spatial interaction in the primatestriate cortex,” J. Neurosci. 8, 1712–1727 (1988).
[PubMed]

J. Opt. Soc. Am. A (5)

J. Physiol. (London) (3)

K. T. Mullen, “The contrast sensitivity of human color vision to red–green andblue–yellow chromatic gratings,” J. Physiol. (London) 359, 381–400 (1985), and references therein. For more reports on color CSF, see D. H. Kelly, “Spatiotemporal variation of chromatic and achromatic contrast threshold,” J. Opt. Soc. Am. 73, 742–750 (1983);E. M. Granger, J. C. Heurtley, “Visual chromaticity modulation transfer function,” J. Opt. Soc. Am. 63, 73–74 (1973);G. J. C. Van der Horst, C. M. M. DeWeert, M. A. Bouman, “Transfer of spatial chromaticity contrast at threshold in the humaneye,” J. Opt. Soc. Am. 57, 1260–1266 (1967).
[Crossref] [PubMed]

C. Blakemore, F. W. Campbell, “On the existence of neurons in the human visual system selectivelysensitive to the orientation and size of retinal images,” J. Physiol. (London) 203, 237–260 (1969).

A. M. Derrington, P. Lennie, “Spatial and temporal contrast sensitivities of neurons in lateral geniculatenucleus of macaque,” J. Physiol. (London) 357, 210–240 (1984); T. N. Wiesel, D. H. Hubel, “Spatial and chromatic interactions in the lateral geniculate body ofthe rhesus monkey,” J. Neurophysiol. 29, 1115–1156 (1966).
[PubMed]

Percept. Psychophys. (1)

A. Elsner, “Hue difference contours can be used in processing orientation information,” Percept. Psychophys. 24, 451–456 (1978).
[Crossref] [PubMed]

QCPE (1)

stepit is a subroutine in J. P. Chandler, “stepit: direct research optimization solution of least-squares problems,” QCPE 11, 307 (1976), and J. P. Chandler, “stepit: direct search psychophysical model forpredicting the visibility of displayed information,” Proc. Soc. Inf. Disp. 21, 229–246 (1976).

Trends Neurosci. (1)

N. W. Daw, “The psychology and physiology of colour vision,” Trends Neurosci. 7, 330–335 (1984).
[Crossref]

Vision Res. (9)

V. C. Smith, R. W. Bowen, J. Pokorny, “Threshold temporal integration of chromatic stimuli,” Vision Res. 24, 653–660 (1984).
[Crossref] [PubMed]

P. Flanagan, P. Cavanagh, O. E. Favreau, “Independent orientation-selective mechanisms for the cardinal directionof color space,” Vision Res. 30, 769–778 (1990).
[Crossref]

V. P. Ferrera, H. R. Wilson, “Spatial frequency tuning of transient non-oriented units,” Vision Res. 25, 67–72 (1984).
[Crossref]

C. R. Michael, “Laminar segregation of color cells in the monkey's striate cortex,” Vision Res. 25, 415–423 (1985).
[Crossref] [PubMed]

R. L. P. Vimal, J. M. Pokorny, V. C. Smith, S. K. Shevell, “Foveal cone thresholds,” Vision Res. 29, 61–78 (1989).
[Crossref] [PubMed]

L. G. Thorell, R. L. De Valois, D. G. Albrecht, “Spatial mapping of monkey V1 cells with pure color and luminance stimuli,” Vision Res. 24, 751–769 (1984).
[Crossref] [PubMed]

A. Bradley, E. Switkes, K. K. De Valois, “Orientation and spatial frequency selectivity of adaptation to colorand luminance gratings,” Vision Res. 28, 841–856 (1988).
[Crossref]

For a Gaussian fit to sine-wave masking data, see M. A. Losada, K. T. Mullen, “The spatial tuning of chromatic mechanisms identified by simultaneousmasking,” Vision Res. 34, 331–334 (1994). For an asymmetric exponential fit to sine-wave masking data and fornoise masking, see M. A. Losada, K. T. Mullen, “Color and luminance spatial tuning estimated by noise masking in theabsence of off-frequency looking,” J. Opt. Soc. Am. A 12, 250–260 (1995).
[Crossref] [PubMed]

H. R. Wilson, D. K. McFarlane, G. C. Phillips, “Spatial frequency tuning of orientation selective units estimated byoblique masking,” Vision Res. 23, 873–882 (1983).
[Crossref]

Other (4)

R. L. DeValois, “Orientation and spatial frequency selectivity: properties and modular organization,” in From Pigments to Perception, A. Valberg, B. B. Lee, eds. (Plenum, New York, 1991), pp. 261–267.

R. L. P. Vimal, R. Pandey, “Orientation bandwidths of spatial frequency mechanism of the Red–Green channel estimated by masking,” in OSA Annual Meeting, Vol. 16 of 1993 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1993), p. 129.

R. Bolt, L. Beranek, E. Newman, Curve Fitting Commands: RS/Explore User's Guide (BBN Research System, Cambridge, Mass., 1986), Book 3, pp. 9-1–9-6.

J. Welkowitz, R. B. Ewen, J. Cohen, Introductory Statistics for the Behavioral Sciences (Academic, New York, 1976), pp. 304–307.

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Figures (5)

Fig. 1
Fig. 1

Spatial color contrast sensitivity function (CSF) is plotted for observer RV in the upper graph and for observer RP in the lower graph. Filled circles: contrast sensitivity data; error bars: 1 standard deviation (SD); solid curves: best fit to contrast sensitivity data by the one-mechanism model. The dotted lines are drawn at half of the maximum contrast sensitivity. The left-hand and top tick labels are in octave values; the right-hand and bottom labels are in linear coordinates. Correlations of data and best fit to the data: 1 (RV and RP); right half-bandwidths (RHBW's) (from 0.0625 cpd) of the CSF data and the best fits: 3.58 octaves (RV) and 3.42 octaves (RP). For details see Section 3 and Subsection 4.A.

Fig. 2
Fig. 2

Threshold elevation (TE) (in octaves) versus mask orientation (in degrees), or TvO, curves, are plotted for observers RV and RP in the upper and lower graphs of the panels, respectively. The left-hand tick labels are in octaves, and the others are in linear coordinates. Dashed and solid curves represent the best fits to the TvO data, plotted by open and filled circles, respectively. Error bar: 1 SD. The relative TE is TE-1.0, so that it is zero at no masking (no change in the threshold contrast as shown by the dotted lines in the lower panels). Test patterns were always vertical, and the orientations were measured from the vertical. The RHBW's are estimated at half of the relative TE and are listed in Table 1. The correlation of data and the best fit, on average, is 0.96 (SD: 0.08). For details see Sections 3–5.  

Fig. 3
Fig. 3

TE versus mask contrast, or (TvC, curves) at 14.5° mask orientation are plotted for observers RV and RP in the upper and lower graphs of the panels, respectively. Dashed and solid curves represent the best fits to the TvC data, plotted by open and filled circles, respectively. Error bar: 1 SD. Dotted lines indicate no masking. The left-hand and bottom tick labels are in octaves; the right-hand and top tick labels are in linear coordinates. The correlation of data and the best fit, on average, is 0.93 (SD: 0.06). The slopes of the TvC (rising positions) data are listed in Table 2. For details see Section 3 and Subsection 4.A.

Fig. 4
Fig. 4

Orientation tuning curves (normalized sensitivity versus orientation) extracted by obtaining the best fit to contrast sensitivity (Fig. 1), TvO (Fig. 2), and TvC (Fig. 3) data simultaneously by using one-mechanism (open and filled circles) and two-mechanism (dashed and solid curves) models (Subsections 4.C and 4.D). The upper and lower graphs of the panels are for observers RV and RP, respectively. Dotted lines are drawn at half of the maximum sensitivity (-1.0 octaves). The left-hand tick labels are in octaves, and the others are in linear coordinates. The orientation RHBW's for one-mechanism and two-mechanism models are plotted in Fig. 5 for details see Subsections 4.B–4.E and Section 5.

Fig. 5
Fig. 5

The best-fit orientation RHBW's (in degrees) were plotted as a function of SF (cpd in octaves) from Fig. 4. Larger-size symbols [larger open (observer RP) and filled (observer RV) circles] are for the one-mechanism model, and smaller-size symbols [smaller open (RP) and filled (RV) circles] are for the two-mechanism model. The solid lines connect the means of the four data points at each SF for orientation half-bandwidths of the SF-tuned color-on-color mechanisms. Error bar: 1 standard error. They were calculated from the solutions with multiple R2 within mean ±3% SD factor (SD/mean) for the chromatic bandwidths. The dotted lines with error bar (1 standard error) represent the average orientation half-bandwidths of the SF-tuned achromatic mechanisms, redrawn from Phillips and Wilson.1 The color mechanisms had broader orientation tuning (mean: 68°–30° for 0.063–8 cpd) than the achromatic mechanisms (32°–20° for 0.5–8 cpd). For details see Subsections 4.C–4.E and Section 5.

Tables (3)

Tables Icon

Table 1 Half-Bandwidths (in Degrees) of TvO Curves (Fig. 2) a

Tables Icon

Table 2 Parameters Estimated by Chromatic One-Mechanism Model a

Tables Icon

Table 3 Comparison of Chromatic and Achromatic Orientation Half-Bandwidths (in Degrees) a

Equations (17)

Equations on this page are rendered with MathJax. Learn more.

TE(θ)=H [S(θ) Cm],
F(0)=S(0),
p(x, y, τ)=Rb(x, y, τ)+Gb(x, y, τ),
Rb(x, y, τ)=Rb0 [1+C p(x, y)] p(τ)
(forreddishpattern),
Gb(x, y, τ)=Gb0 [1±C p(x, y)] p(τ)
(forgreenishpattern),
Rb0=R0+Br0,
Gb0=G0+Bg0,
p(τ)=exp(-τ2/στ2).
p(x, y)=pt(x, y)=D6(x, σ)exp[-y2/(4σ)2],
D6(x, σ)={[120-720(x/σ)2+480(x/σ)4-64(x/σ)6]/σ6}exp(-x2/σ2),
σ=3/(πωmax).
p(x, y)=pm(x, y)=cos(2πωx),
x=x cos θ+y sin θ.
p(x, y)=pm(x, y)=cos(2πωy).
[C p(x, y)]t+m=Ctpt(x, y)+Cmpm(x, y).

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