Abstract

We measured modulation sensitivity to a pair of equally luminous sinusoidally modulated lights (568 and 630 nm) as a function of their relative phase. Measurements were made for 2, 3, 6, and 12 Hz at a retinal illuminance of 100 Td. The data indicated that two processes were active and their outputs combined by a vector summation rule. There was a phase shift of −18° to −20° (630 nm leads 568 nm) at 6 Hz, no phase shift at 12 Hz, an equivocal shift at 2 Hz, and an indeterminate shift at 3 Hz. At frequencies where a phase shift was observed, our analysis indicated that the phase shift affected sensitivities measured at all relative phase settings. These results are inconsistent with models postulating equal contributions of long-wavelength- and middle-wavelength-receptors to centers and surrounds of processes responsible for the detection of luminance flicker.

© 1986 Optical Society of America

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References

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  1. H. deLange, “Research into the dynamic nature of the human fovea-cortex systems with intermittent and modulated light. I. Attenuation characteristics with white and colored light,” J. Opt. Soc. Am. 48, 777–784 (1958).
    [Crossref]
  2. H. deLange, “Research into the dynamic nature of the human fovea-cortex systems with intermittent and modulated light. II. Phase shift in brightness and delay in color perception,” J. Opt. Soc. Am. 48, 784–789 (1958).
    [Crossref]
  3. D. H. Kelly, D. van Norren, “Two-band model of heterochromatic flicker,” J. Opt. Soc. Am. 67, 1081–1091 (1977).
    [Crossref] [PubMed]
  4. P. L. Walraven, H. J. Leebeek, “Phase shift of alternating coloured stimuli,” Doc. Ophthalmol. 18, 56–71 (1964).
    [Crossref] [PubMed]
  5. M. W. von Grunau, “Lateral interactions and rod intrusion in color flicker,” Vision Res. 17, 911–916 (1977).
    [Crossref] [PubMed]
  6. J. J. Vos, P. L. Walraven, “Phase shift in the perception of sinusoidally modulated light at low luminances,” in Performance of the Eye at Low Luminances: Proceedings of the Colloquium in Delft 1965, M. A. Bouman, J. J. Vos, eds. (Excerpta Medica Foundation, New York, 1966), pp. 91–103.
  7. J. J. Wisowaty, “Estimates for the temporal response characteristics of chromatic pathways,” J. Opt. Soc. Am. 71, 970–977 (1981).
    [Crossref] [PubMed]
  8. D. T. Lindsey, “Phase-dependent sensitivity to heterochromatic flicker,” thesis (University of Chicago, Ill., 1985).
  9. R. F. Quick, “A vector-magnitude model of contrast detection,” Kybernetick 16, 65–67 (1974).
    [Crossref]
  10. K. Yamaoka, Y. Tanigawara, T. Nakagawa, T. Uno, “A pharmacokinetic analysis program (Multi) for microcomputers,” J. Pharmacobio-Dynamics 4, 879–885 (1981).
    [Crossref]
  11. J. D. Mollon, “Post-receptoral processes in colour vision,” Nature 283, 623–624 (1980).
    [Crossref] [PubMed]
  12. D. L. MacAdam, “Colour discrimination and the influence of colour contrast on acuity,” Doc. Ophthalmol. 3, 214–233 (1949).
    [Crossref] [PubMed]
  13. C. Noorlander, M. J. G. Heuts, J. J. Koenderink, “Influence of the target size on the detection of threshold for luminance and chromaticity contrast,” J. Opt. Soc. Am. 70, 1116–1121 (1980).
    [Crossref] [PubMed]
  14. V. C. Smith, R. W. Bowen, J. Pokorny, “Threshold temporal integration of chromatic stimuli,” Vision Res. 24, 653–659 (1984).
    [Crossref] [PubMed]
  15. S. L. Guth, H. R. Lodge, “Heterochromatic additivity, foveal spectral sensitivity, and a new color model,” J. Opt. Soc. Am. 63, 450–462 (1973).
    [Crossref] [PubMed]
  16. C. R. Ingling, B. H. Tsou, “Orthogonal combinations of three visual channels,” Vision Res. 17, 1075–1082 (1977).
    [Crossref]
  17. K. Kranda, P. E. King-Smith, “Detection of colored stimuli by independent linear systems,” Vision Res. 19, 733–745 (1979).
    [Crossref]
  18. T. J. T. P. van den Berg, H. Spekreijse, “Interaction between rod and cone signals studied with temporal sine wave stimulation,” J. Opt. Soc. Am. 65, 1210–1217 (1977).
    [Crossref]
  19. R. M. Boynton, W. S. Baron, “Sinusoidal flicker characteristics of primate cones in response to heterochromatic stimuli,” J. Opt. Soc. Am. 65, 1091–1100 (1975).
    [Crossref] [PubMed]
  20. B. J. Nunn, J. L. Schnapf, D. A. Baylor, “Spectral sensitivity of single cones in the retina of Macaca fascicularis,” Nature 309, 264–266 (1984).
    [Crossref] [PubMed]
  21. D. A. Baylor, A. L. Hodgkin, “Changes in time scale and sensitivity in turtle photoreceptors,” J. Physiol. (London) 242, 729–758 (1974).
  22. B. Drum, “Cone response latency and log sensitivity proportional changes with light adaptation,” Vision Res. 24, 323–331 (1984).
    [Crossref]
  23. P. Gouras, E. Zrenner, “Enhancement of luminance flicker by color-opponent mechanisms,” Science 205, 587–589 (1979).
    [Crossref] [PubMed]
  24. F. M. De Monasterio, P. Gouras, “Functional properties of ganglion cells of the rhesus monkey retina,” J. Physiol. (London) 251, 167–195 (1975).
  25. C. R. Ingling, E. Martinez, “Simple-opponent receptive fields are asymmetrical: g-cone centers predominate,” J. Opt. Soc. Am. 73, 1527–1532 (1983).
    [Crossref] [PubMed]
  26. D. H. Kelly, “Luminous and chromatic flickering patterns have opposite effects,” Science 188, 371–372 (1975).
    [Crossref] [PubMed]
  27. C. R. Ingling, E. Martinez, “The spatiochromatic signal of the r-g channel,” in Color Vision: Physiology and Psychophysics, J. D. Mollon, L. T. Sharpe, eds. (Academic, New York, 1983), pp. 433–444.
  28. D. H. Kelly, “Spatiotemporal variation of chromatic and achromatic contrast thresholds,” J. Opt. Soc. Am. 73, 742–750 (1983).
    [Crossref] [PubMed]
  29. J. Krauskopf, “Discrimination and detection of changes in luminance,” Vision Res. 20, 671–677 (1980).
    [Crossref] [PubMed]

1984 (3)

V. C. Smith, R. W. Bowen, J. Pokorny, “Threshold temporal integration of chromatic stimuli,” Vision Res. 24, 653–659 (1984).
[Crossref] [PubMed]

B. J. Nunn, J. L. Schnapf, D. A. Baylor, “Spectral sensitivity of single cones in the retina of Macaca fascicularis,” Nature 309, 264–266 (1984).
[Crossref] [PubMed]

B. Drum, “Cone response latency and log sensitivity proportional changes with light adaptation,” Vision Res. 24, 323–331 (1984).
[Crossref]

1983 (2)

1981 (2)

J. J. Wisowaty, “Estimates for the temporal response characteristics of chromatic pathways,” J. Opt. Soc. Am. 71, 970–977 (1981).
[Crossref] [PubMed]

K. Yamaoka, Y. Tanigawara, T. Nakagawa, T. Uno, “A pharmacokinetic analysis program (Multi) for microcomputers,” J. Pharmacobio-Dynamics 4, 879–885 (1981).
[Crossref]

1980 (3)

J. D. Mollon, “Post-receptoral processes in colour vision,” Nature 283, 623–624 (1980).
[Crossref] [PubMed]

C. Noorlander, M. J. G. Heuts, J. J. Koenderink, “Influence of the target size on the detection of threshold for luminance and chromaticity contrast,” J. Opt. Soc. Am. 70, 1116–1121 (1980).
[Crossref] [PubMed]

J. Krauskopf, “Discrimination and detection of changes in luminance,” Vision Res. 20, 671–677 (1980).
[Crossref] [PubMed]

1979 (2)

P. Gouras, E. Zrenner, “Enhancement of luminance flicker by color-opponent mechanisms,” Science 205, 587–589 (1979).
[Crossref] [PubMed]

K. Kranda, P. E. King-Smith, “Detection of colored stimuli by independent linear systems,” Vision Res. 19, 733–745 (1979).
[Crossref]

1977 (4)

T. J. T. P. van den Berg, H. Spekreijse, “Interaction between rod and cone signals studied with temporal sine wave stimulation,” J. Opt. Soc. Am. 65, 1210–1217 (1977).
[Crossref]

M. W. von Grunau, “Lateral interactions and rod intrusion in color flicker,” Vision Res. 17, 911–916 (1977).
[Crossref] [PubMed]

D. H. Kelly, D. van Norren, “Two-band model of heterochromatic flicker,” J. Opt. Soc. Am. 67, 1081–1091 (1977).
[Crossref] [PubMed]

C. R. Ingling, B. H. Tsou, “Orthogonal combinations of three visual channels,” Vision Res. 17, 1075–1082 (1977).
[Crossref]

1975 (3)

F. M. De Monasterio, P. Gouras, “Functional properties of ganglion cells of the rhesus monkey retina,” J. Physiol. (London) 251, 167–195 (1975).

D. H. Kelly, “Luminous and chromatic flickering patterns have opposite effects,” Science 188, 371–372 (1975).
[Crossref] [PubMed]

R. M. Boynton, W. S. Baron, “Sinusoidal flicker characteristics of primate cones in response to heterochromatic stimuli,” J. Opt. Soc. Am. 65, 1091–1100 (1975).
[Crossref] [PubMed]

1974 (2)

D. A. Baylor, A. L. Hodgkin, “Changes in time scale and sensitivity in turtle photoreceptors,” J. Physiol. (London) 242, 729–758 (1974).

R. F. Quick, “A vector-magnitude model of contrast detection,” Kybernetick 16, 65–67 (1974).
[Crossref]

1973 (1)

1964 (1)

P. L. Walraven, H. J. Leebeek, “Phase shift of alternating coloured stimuli,” Doc. Ophthalmol. 18, 56–71 (1964).
[Crossref] [PubMed]

1958 (2)

1949 (1)

D. L. MacAdam, “Colour discrimination and the influence of colour contrast on acuity,” Doc. Ophthalmol. 3, 214–233 (1949).
[Crossref] [PubMed]

Baron, W. S.

Baylor, D. A.

B. J. Nunn, J. L. Schnapf, D. A. Baylor, “Spectral sensitivity of single cones in the retina of Macaca fascicularis,” Nature 309, 264–266 (1984).
[Crossref] [PubMed]

D. A. Baylor, A. L. Hodgkin, “Changes in time scale and sensitivity in turtle photoreceptors,” J. Physiol. (London) 242, 729–758 (1974).

Bowen, R. W.

V. C. Smith, R. W. Bowen, J. Pokorny, “Threshold temporal integration of chromatic stimuli,” Vision Res. 24, 653–659 (1984).
[Crossref] [PubMed]

Boynton, R. M.

De Monasterio, F. M.

F. M. De Monasterio, P. Gouras, “Functional properties of ganglion cells of the rhesus monkey retina,” J. Physiol. (London) 251, 167–195 (1975).

deLange, H.

Drum, B.

B. Drum, “Cone response latency and log sensitivity proportional changes with light adaptation,” Vision Res. 24, 323–331 (1984).
[Crossref]

Gouras, P.

P. Gouras, E. Zrenner, “Enhancement of luminance flicker by color-opponent mechanisms,” Science 205, 587–589 (1979).
[Crossref] [PubMed]

F. M. De Monasterio, P. Gouras, “Functional properties of ganglion cells of the rhesus monkey retina,” J. Physiol. (London) 251, 167–195 (1975).

Guth, S. L.

Heuts, M. J. G.

Hodgkin, A. L.

D. A. Baylor, A. L. Hodgkin, “Changes in time scale and sensitivity in turtle photoreceptors,” J. Physiol. (London) 242, 729–758 (1974).

Ingling, C. R.

C. R. Ingling, E. Martinez, “Simple-opponent receptive fields are asymmetrical: g-cone centers predominate,” J. Opt. Soc. Am. 73, 1527–1532 (1983).
[Crossref] [PubMed]

C. R. Ingling, B. H. Tsou, “Orthogonal combinations of three visual channels,” Vision Res. 17, 1075–1082 (1977).
[Crossref]

C. R. Ingling, E. Martinez, “The spatiochromatic signal of the r-g channel,” in Color Vision: Physiology and Psychophysics, J. D. Mollon, L. T. Sharpe, eds. (Academic, New York, 1983), pp. 433–444.

Kelly, D. H.

King-Smith, P. E.

K. Kranda, P. E. King-Smith, “Detection of colored stimuli by independent linear systems,” Vision Res. 19, 733–745 (1979).
[Crossref]

Koenderink, J. J.

Kranda, K.

K. Kranda, P. E. King-Smith, “Detection of colored stimuli by independent linear systems,” Vision Res. 19, 733–745 (1979).
[Crossref]

Krauskopf, J.

J. Krauskopf, “Discrimination and detection of changes in luminance,” Vision Res. 20, 671–677 (1980).
[Crossref] [PubMed]

Leebeek, H. J.

P. L. Walraven, H. J. Leebeek, “Phase shift of alternating coloured stimuli,” Doc. Ophthalmol. 18, 56–71 (1964).
[Crossref] [PubMed]

Lindsey, D. T.

D. T. Lindsey, “Phase-dependent sensitivity to heterochromatic flicker,” thesis (University of Chicago, Ill., 1985).

Lodge, H. R.

MacAdam, D. L.

D. L. MacAdam, “Colour discrimination and the influence of colour contrast on acuity,” Doc. Ophthalmol. 3, 214–233 (1949).
[Crossref] [PubMed]

Martinez, E.

C. R. Ingling, E. Martinez, “Simple-opponent receptive fields are asymmetrical: g-cone centers predominate,” J. Opt. Soc. Am. 73, 1527–1532 (1983).
[Crossref] [PubMed]

C. R. Ingling, E. Martinez, “The spatiochromatic signal of the r-g channel,” in Color Vision: Physiology and Psychophysics, J. D. Mollon, L. T. Sharpe, eds. (Academic, New York, 1983), pp. 433–444.

Mollon, J. D.

J. D. Mollon, “Post-receptoral processes in colour vision,” Nature 283, 623–624 (1980).
[Crossref] [PubMed]

Nakagawa, T.

K. Yamaoka, Y. Tanigawara, T. Nakagawa, T. Uno, “A pharmacokinetic analysis program (Multi) for microcomputers,” J. Pharmacobio-Dynamics 4, 879–885 (1981).
[Crossref]

Noorlander, C.

Nunn, B. J.

B. J. Nunn, J. L. Schnapf, D. A. Baylor, “Spectral sensitivity of single cones in the retina of Macaca fascicularis,” Nature 309, 264–266 (1984).
[Crossref] [PubMed]

Pokorny, J.

V. C. Smith, R. W. Bowen, J. Pokorny, “Threshold temporal integration of chromatic stimuli,” Vision Res. 24, 653–659 (1984).
[Crossref] [PubMed]

Quick, R. F.

R. F. Quick, “A vector-magnitude model of contrast detection,” Kybernetick 16, 65–67 (1974).
[Crossref]

Schnapf, J. L.

B. J. Nunn, J. L. Schnapf, D. A. Baylor, “Spectral sensitivity of single cones in the retina of Macaca fascicularis,” Nature 309, 264–266 (1984).
[Crossref] [PubMed]

Smith, V. C.

V. C. Smith, R. W. Bowen, J. Pokorny, “Threshold temporal integration of chromatic stimuli,” Vision Res. 24, 653–659 (1984).
[Crossref] [PubMed]

Spekreijse, H.

T. J. T. P. van den Berg, H. Spekreijse, “Interaction between rod and cone signals studied with temporal sine wave stimulation,” J. Opt. Soc. Am. 65, 1210–1217 (1977).
[Crossref]

Tanigawara, Y.

K. Yamaoka, Y. Tanigawara, T. Nakagawa, T. Uno, “A pharmacokinetic analysis program (Multi) for microcomputers,” J. Pharmacobio-Dynamics 4, 879–885 (1981).
[Crossref]

Tsou, B. H.

C. R. Ingling, B. H. Tsou, “Orthogonal combinations of three visual channels,” Vision Res. 17, 1075–1082 (1977).
[Crossref]

Uno, T.

K. Yamaoka, Y. Tanigawara, T. Nakagawa, T. Uno, “A pharmacokinetic analysis program (Multi) for microcomputers,” J. Pharmacobio-Dynamics 4, 879–885 (1981).
[Crossref]

van den Berg, T. J. T. P.

T. J. T. P. van den Berg, H. Spekreijse, “Interaction between rod and cone signals studied with temporal sine wave stimulation,” J. Opt. Soc. Am. 65, 1210–1217 (1977).
[Crossref]

van Norren, D.

von Grunau, M. W.

M. W. von Grunau, “Lateral interactions and rod intrusion in color flicker,” Vision Res. 17, 911–916 (1977).
[Crossref] [PubMed]

Vos, J. J.

J. J. Vos, P. L. Walraven, “Phase shift in the perception of sinusoidally modulated light at low luminances,” in Performance of the Eye at Low Luminances: Proceedings of the Colloquium in Delft 1965, M. A. Bouman, J. J. Vos, eds. (Excerpta Medica Foundation, New York, 1966), pp. 91–103.

Walraven, P. L.

P. L. Walraven, H. J. Leebeek, “Phase shift of alternating coloured stimuli,” Doc. Ophthalmol. 18, 56–71 (1964).
[Crossref] [PubMed]

J. J. Vos, P. L. Walraven, “Phase shift in the perception of sinusoidally modulated light at low luminances,” in Performance of the Eye at Low Luminances: Proceedings of the Colloquium in Delft 1965, M. A. Bouman, J. J. Vos, eds. (Excerpta Medica Foundation, New York, 1966), pp. 91–103.

Wisowaty, J. J.

Yamaoka, K.

K. Yamaoka, Y. Tanigawara, T. Nakagawa, T. Uno, “A pharmacokinetic analysis program (Multi) for microcomputers,” J. Pharmacobio-Dynamics 4, 879–885 (1981).
[Crossref]

Zrenner, E.

P. Gouras, E. Zrenner, “Enhancement of luminance flicker by color-opponent mechanisms,” Science 205, 587–589 (1979).
[Crossref] [PubMed]

Doc. Ophthalmol. (2)

P. L. Walraven, H. J. Leebeek, “Phase shift of alternating coloured stimuli,” Doc. Ophthalmol. 18, 56–71 (1964).
[Crossref] [PubMed]

D. L. MacAdam, “Colour discrimination and the influence of colour contrast on acuity,” Doc. Ophthalmol. 3, 214–233 (1949).
[Crossref] [PubMed]

J. Opt. Soc. Am. (10)

C. Noorlander, M. J. G. Heuts, J. J. Koenderink, “Influence of the target size on the detection of threshold for luminance and chromaticity contrast,” J. Opt. Soc. Am. 70, 1116–1121 (1980).
[Crossref] [PubMed]

S. L. Guth, H. R. Lodge, “Heterochromatic additivity, foveal spectral sensitivity, and a new color model,” J. Opt. Soc. Am. 63, 450–462 (1973).
[Crossref] [PubMed]

T. J. T. P. van den Berg, H. Spekreijse, “Interaction between rod and cone signals studied with temporal sine wave stimulation,” J. Opt. Soc. Am. 65, 1210–1217 (1977).
[Crossref]

R. M. Boynton, W. S. Baron, “Sinusoidal flicker characteristics of primate cones in response to heterochromatic stimuli,” J. Opt. Soc. Am. 65, 1091–1100 (1975).
[Crossref] [PubMed]

H. deLange, “Research into the dynamic nature of the human fovea-cortex systems with intermittent and modulated light. I. Attenuation characteristics with white and colored light,” J. Opt. Soc. Am. 48, 777–784 (1958).
[Crossref]

H. deLange, “Research into the dynamic nature of the human fovea-cortex systems with intermittent and modulated light. II. Phase shift in brightness and delay in color perception,” J. Opt. Soc. Am. 48, 784–789 (1958).
[Crossref]

D. H. Kelly, D. van Norren, “Two-band model of heterochromatic flicker,” J. Opt. Soc. Am. 67, 1081–1091 (1977).
[Crossref] [PubMed]

J. J. Wisowaty, “Estimates for the temporal response characteristics of chromatic pathways,” J. Opt. Soc. Am. 71, 970–977 (1981).
[Crossref] [PubMed]

C. R. Ingling, E. Martinez, “Simple-opponent receptive fields are asymmetrical: g-cone centers predominate,” J. Opt. Soc. Am. 73, 1527–1532 (1983).
[Crossref] [PubMed]

D. H. Kelly, “Spatiotemporal variation of chromatic and achromatic contrast thresholds,” J. Opt. Soc. Am. 73, 742–750 (1983).
[Crossref] [PubMed]

J. Pharmacobio-Dynamics (1)

K. Yamaoka, Y. Tanigawara, T. Nakagawa, T. Uno, “A pharmacokinetic analysis program (Multi) for microcomputers,” J. Pharmacobio-Dynamics 4, 879–885 (1981).
[Crossref]

J. Physiol. (London) (2)

D. A. Baylor, A. L. Hodgkin, “Changes in time scale and sensitivity in turtle photoreceptors,” J. Physiol. (London) 242, 729–758 (1974).

F. M. De Monasterio, P. Gouras, “Functional properties of ganglion cells of the rhesus monkey retina,” J. Physiol. (London) 251, 167–195 (1975).

Kybernetick (1)

R. F. Quick, “A vector-magnitude model of contrast detection,” Kybernetick 16, 65–67 (1974).
[Crossref]

Nature (2)

B. J. Nunn, J. L. Schnapf, D. A. Baylor, “Spectral sensitivity of single cones in the retina of Macaca fascicularis,” Nature 309, 264–266 (1984).
[Crossref] [PubMed]

J. D. Mollon, “Post-receptoral processes in colour vision,” Nature 283, 623–624 (1980).
[Crossref] [PubMed]

Science (2)

P. Gouras, E. Zrenner, “Enhancement of luminance flicker by color-opponent mechanisms,” Science 205, 587–589 (1979).
[Crossref] [PubMed]

D. H. Kelly, “Luminous and chromatic flickering patterns have opposite effects,” Science 188, 371–372 (1975).
[Crossref] [PubMed]

Vision Res. (6)

J. Krauskopf, “Discrimination and detection of changes in luminance,” Vision Res. 20, 671–677 (1980).
[Crossref] [PubMed]

M. W. von Grunau, “Lateral interactions and rod intrusion in color flicker,” Vision Res. 17, 911–916 (1977).
[Crossref] [PubMed]

B. Drum, “Cone response latency and log sensitivity proportional changes with light adaptation,” Vision Res. 24, 323–331 (1984).
[Crossref]

C. R. Ingling, B. H. Tsou, “Orthogonal combinations of three visual channels,” Vision Res. 17, 1075–1082 (1977).
[Crossref]

K. Kranda, P. E. King-Smith, “Detection of colored stimuli by independent linear systems,” Vision Res. 19, 733–745 (1979).
[Crossref]

V. C. Smith, R. W. Bowen, J. Pokorny, “Threshold temporal integration of chromatic stimuli,” Vision Res. 24, 653–659 (1984).
[Crossref] [PubMed]

Other (3)

J. J. Vos, P. L. Walraven, “Phase shift in the perception of sinusoidally modulated light at low luminances,” in Performance of the Eye at Low Luminances: Proceedings of the Colloquium in Delft 1965, M. A. Bouman, J. J. Vos, eds. (Excerpta Medica Foundation, New York, 1966), pp. 91–103.

D. T. Lindsey, “Phase-dependent sensitivity to heterochromatic flicker,” thesis (University of Chicago, Ill., 1985).

C. R. Ingling, E. Martinez, “The spatiochromatic signal of the r-g channel,” in Color Vision: Physiology and Psychophysics, J. D. Mollon, L. T. Sharpe, eds. (Academic, New York, 1983), pp. 433–444.

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Figures (4)

Fig. 1
Fig. 1

Schematic of the experimental apparatus including the two-channel Maxwellian-view optical system and computer interface for driving the LED sources. Details of the apparatus are given in the text. S, Source; FB, filter box; DM, dichroic mirror; L, lens; FS, field stop; AP, artificial pupil.

Fig. 2
Fig. 2

Theoretical functions showing the response of independent channels as a function of phase. Dashed lines show the effect of a phase shift. Left panel shows chromatic sensitivity better than achromatic; right panel shows the reverse.

Fig. 3
Fig. 3

Average modulation thresholds as a function of phase setting. Data are plotted for the four test frequencies: 2, 3, 6, and 12 Hz. Error bars above and below each data point indicate ±1 SEM. The curves drawn through the data for each frequency were derived from a model of flicker detection described in the text. Left panel shows data for observer DTL; right panel shows data for observer DHL.

Fig. 4
Fig. 4

Comparison of the 3-Hz data of observer DTL with summation model predictions based on three values of summation index (P). Dotted line, P = 1; solid line, P = 2; dashed line, P = ∞. Error bars above and below each data point indicate ±1 SEM.

Tables (1)

Tables Icon

Table 1 Best Fits and Sum of Squared Residuals Obtained Assuming P = 2 and Optimizing MO, M180, and ϕ at Each Frequency by Least-Squares Criterion M ( θ , F ) = 1 [ | cos ( θ ϕ ) 2 MO ( F ) | P + | sin ( θ ϕ ) 2 M 180 ( F ) | P ] 1 / P

Equations (11)

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

M = ( I max I min ) / ( I max + I min ) ,
L ( t ) = L + ( M / 2 ) { sin [ ( f t / 360 ) θ ] + sin ( f t / 360 ) } ,
C ( t ) = C + ( M / 2 ) { sin [ ( f t / 360 ) θ ] sin ( f t / 360 ) } .
L ( t ) = L + [ M cos ( θ / 2 ) ] { sin [ ( f t / 360 ) ( θ / 2 ) ] } ,
C ( t ) = C + [ M sin ( θ / 2 ) ] { cos [ ( f t / 360 ) ( θ / 2 ) ] } .
R = M ( 1 / M T ) .
M L = ( M LT ) / cos [ ( θ ϕ L ) / 2 ] ,
M C = ( M CT ) / sin [ ( θ ϕ C ) / 2 ] .
R = ( | R L | P + | R C | P ) 1 / P ,
M = 1 / ( { | cos [ ( θ ϕ ) / 2 ] / M LT | P + | sin [ ( θ ϕ ) / 2 ] / M CT | P } 1 / P ) .
M ( θ , F ) = 1 [ | cos ( θ ϕ ) 2 MO ( F ) | P + | sin ( θ ϕ ) 2 M 180 ( F ) | P ] 1 / P

Metrics