Abstract

Previous studies of spatial frequency and orientation discrimination [ Vision Res. 32, 1885 ( 1992)] suggest the existence of two second-order cortical mechanisms: one that mediates spatial frequency discriminations and sums signals across orientations and one that mediates orientation discriminations and sums signals across spatial frequency bands. The existence of each mechanism is tested in an uncertainty experiment in which the observer does not know which of two hypothetically pooled signals deviates from the standard but must judge whether the deviation is an increment or a decrement. No uncertainty effect is expected if the signals are completely pooled. Observed effects are compared with this expectation and with both theoretical and empirical estimates of the effects expected if the signals are processed separately. Results support the existence of the first mechanism, but not its exclusive role in mediating spatial frequency judgments, and support the exclusive role of the second mechanism in mediating orientation judgments.

© 1996 Optical Society of America

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References

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  1. N. V. S. Graham, Visual Pattern Analyzers (Oxford U. Press, New York, 1989).
    [CrossRef]
  2. L. A. Olzak, J. P. Thomas, “Seeing spatial patterns,” in Sensory Processes and Perception, Vol. 1 of Handbook of Perception and Human Performance, K. Boff, L. Kaufman, J. P. Thomas, eds. (Wiley, New York, 1986), pp. 7-1–7-56.
  3. A. C. Bovik, M. Clark, W. S. Geisler, “Multichannel texture analysis using localized spatial filters,” IEEE Trans. Patt. Analy. Mach. Vis. 12, 55–73 (1990).
    [CrossRef]
  4. M. S. Landy, J. R. Bergen, “Texture segregation and orientation gradient,” Vision Res. 31, 679–692 (1991).
    [CrossRef] [PubMed]
  5. N. Graham, J. Beck, A. Sutter, “Nonlinear processes in spatial-frequency channel models of perceived texture segregation: effects of sign and amount of contrast,” Vision Res. 32, 719–743 (1992).
    [CrossRef] [PubMed]
  6. H. R. Wilson, W. A. Richards, “Curvature and separation discrimination at texture boundaries,” J. Opt. Soc. Am. A 9, 1653–1662 (1992).
    [CrossRef] [PubMed]
  7. L. A. Olzak, J. P. Thomas, “Configural effects constrain Fourier models of pattern discrimination,” Vision Res. 32, 1885–1898 (1992).
    [CrossRef] [PubMed]
  8. L. A. Olzak, J. P. Thomas, “When orthogonal orientations are not processed independently,” Vision Res. 31, 51–57 (1991).
    [CrossRef] [PubMed]
  9. W. P. Tanner, “Physiological implications of psychophysical data,” Ann. N. Y. Acad. Sci. 89, 752–765 (1961).
    [CrossRef] [PubMed]
  10. E. T. Davis, N. Graham, “Spatial frequency uncertainty effects in the detection of visual sinusoidal gratings,” Vision Res. 21, 705–712 (1981).
    [CrossRef]
  11. E. T. Davis, P. Kramer, N. Graham, “Uncertainty about spatial frequency, spatial position, or contrast of visual patterns,” Percept. Psychophys. 33, 20–28 (1983).
    [CrossRef] [PubMed]
  12. In theory, there is a third possible explanation for uncertainty effects when only one component of the stimulus differs from the standard: in certainty conditions the subject knows which component has the standard value and bases the judgment on a simultaneous comparison between the components; in the uncertainty conditions such a comparison is ambiguous, and the subject must rely on an absolute judgment or a comparison with a remembered standard value. However, Olzak and Thomas found that, for the fine discriminations measured in this paper, subjects do not base their judgments on relative comparisons between components even when such judgments would be more accurate.7
  13. M. W. Greenlee, J. P. Thomas, “Simultaneous discrimination of the spatial frequency and contrast of periodic stimuli,” J. Opt. Soc. Am. A 10, 395–404 (1993).
    [CrossRef] [PubMed]
  14. S. Magnussen, M. W. Greenlee, J. P. Thomas, “Parallel processing in visual short-term memory,” J. Exp. Psychol. (to be published).
  15. J. P. Thomas, “Independent processing of suprathreshold spatial gratings as a function of their separation in spatial frequency,” J. Opt. Soc. Am. A 6, 1102–1111 (1989).
    [CrossRef] [PubMed]
  16. J. P. Thomas, L. A. Olzak, “Cue summation is spatial discriminations,” Vision Res. 30, 1865–1875 (1990).
    [CrossRef]
  17. A. B. Watson, K. R. Nielson, A. Poirson, A. Fitzhugh, A. Bilson, K. Nguyen, A. Ahumada, “Use of raster framebuffer in vision research,” Behav. Res. Methods Instrum. Comput. 18, 587–594 (1986).
    [CrossRef]
  18. B. G. Smith, J. P. Thomas, “Why are some spatial discriminations independent of contrast?” J. Opt. Soc. Am. A 6, 713–724 (1989).
    [CrossRef] [PubMed]

1993 (1)

1992 (3)

N. Graham, J. Beck, A. Sutter, “Nonlinear processes in spatial-frequency channel models of perceived texture segregation: effects of sign and amount of contrast,” Vision Res. 32, 719–743 (1992).
[CrossRef] [PubMed]

H. R. Wilson, W. A. Richards, “Curvature and separation discrimination at texture boundaries,” J. Opt. Soc. Am. A 9, 1653–1662 (1992).
[CrossRef] [PubMed]

L. A. Olzak, J. P. Thomas, “Configural effects constrain Fourier models of pattern discrimination,” Vision Res. 32, 1885–1898 (1992).
[CrossRef] [PubMed]

1991 (2)

L. A. Olzak, J. P. Thomas, “When orthogonal orientations are not processed independently,” Vision Res. 31, 51–57 (1991).
[CrossRef] [PubMed]

M. S. Landy, J. R. Bergen, “Texture segregation and orientation gradient,” Vision Res. 31, 679–692 (1991).
[CrossRef] [PubMed]

1990 (2)

A. C. Bovik, M. Clark, W. S. Geisler, “Multichannel texture analysis using localized spatial filters,” IEEE Trans. Patt. Analy. Mach. Vis. 12, 55–73 (1990).
[CrossRef]

J. P. Thomas, L. A. Olzak, “Cue summation is spatial discriminations,” Vision Res. 30, 1865–1875 (1990).
[CrossRef]

1989 (2)

1986 (1)

A. B. Watson, K. R. Nielson, A. Poirson, A. Fitzhugh, A. Bilson, K. Nguyen, A. Ahumada, “Use of raster framebuffer in vision research,” Behav. Res. Methods Instrum. Comput. 18, 587–594 (1986).
[CrossRef]

1983 (1)

E. T. Davis, P. Kramer, N. Graham, “Uncertainty about spatial frequency, spatial position, or contrast of visual patterns,” Percept. Psychophys. 33, 20–28 (1983).
[CrossRef] [PubMed]

1981 (1)

E. T. Davis, N. Graham, “Spatial frequency uncertainty effects in the detection of visual sinusoidal gratings,” Vision Res. 21, 705–712 (1981).
[CrossRef]

1961 (1)

W. P. Tanner, “Physiological implications of psychophysical data,” Ann. N. Y. Acad. Sci. 89, 752–765 (1961).
[CrossRef] [PubMed]

Ahumada, A.

A. B. Watson, K. R. Nielson, A. Poirson, A. Fitzhugh, A. Bilson, K. Nguyen, A. Ahumada, “Use of raster framebuffer in vision research,” Behav. Res. Methods Instrum. Comput. 18, 587–594 (1986).
[CrossRef]

Beck, J.

N. Graham, J. Beck, A. Sutter, “Nonlinear processes in spatial-frequency channel models of perceived texture segregation: effects of sign and amount of contrast,” Vision Res. 32, 719–743 (1992).
[CrossRef] [PubMed]

Bergen, J. R.

M. S. Landy, J. R. Bergen, “Texture segregation and orientation gradient,” Vision Res. 31, 679–692 (1991).
[CrossRef] [PubMed]

Bilson, A.

A. B. Watson, K. R. Nielson, A. Poirson, A. Fitzhugh, A. Bilson, K. Nguyen, A. Ahumada, “Use of raster framebuffer in vision research,” Behav. Res. Methods Instrum. Comput. 18, 587–594 (1986).
[CrossRef]

Bovik, A. C.

A. C. Bovik, M. Clark, W. S. Geisler, “Multichannel texture analysis using localized spatial filters,” IEEE Trans. Patt. Analy. Mach. Vis. 12, 55–73 (1990).
[CrossRef]

Clark, M.

A. C. Bovik, M. Clark, W. S. Geisler, “Multichannel texture analysis using localized spatial filters,” IEEE Trans. Patt. Analy. Mach. Vis. 12, 55–73 (1990).
[CrossRef]

Davis, E. T.

E. T. Davis, P. Kramer, N. Graham, “Uncertainty about spatial frequency, spatial position, or contrast of visual patterns,” Percept. Psychophys. 33, 20–28 (1983).
[CrossRef] [PubMed]

E. T. Davis, N. Graham, “Spatial frequency uncertainty effects in the detection of visual sinusoidal gratings,” Vision Res. 21, 705–712 (1981).
[CrossRef]

Fitzhugh, A.

A. B. Watson, K. R. Nielson, A. Poirson, A. Fitzhugh, A. Bilson, K. Nguyen, A. Ahumada, “Use of raster framebuffer in vision research,” Behav. Res. Methods Instrum. Comput. 18, 587–594 (1986).
[CrossRef]

Geisler, W. S.

A. C. Bovik, M. Clark, W. S. Geisler, “Multichannel texture analysis using localized spatial filters,” IEEE Trans. Patt. Analy. Mach. Vis. 12, 55–73 (1990).
[CrossRef]

Graham, N.

N. Graham, J. Beck, A. Sutter, “Nonlinear processes in spatial-frequency channel models of perceived texture segregation: effects of sign and amount of contrast,” Vision Res. 32, 719–743 (1992).
[CrossRef] [PubMed]

E. T. Davis, P. Kramer, N. Graham, “Uncertainty about spatial frequency, spatial position, or contrast of visual patterns,” Percept. Psychophys. 33, 20–28 (1983).
[CrossRef] [PubMed]

E. T. Davis, N. Graham, “Spatial frequency uncertainty effects in the detection of visual sinusoidal gratings,” Vision Res. 21, 705–712 (1981).
[CrossRef]

Graham, N. V. S.

N. V. S. Graham, Visual Pattern Analyzers (Oxford U. Press, New York, 1989).
[CrossRef]

Greenlee, M. W.

M. W. Greenlee, J. P. Thomas, “Simultaneous discrimination of the spatial frequency and contrast of periodic stimuli,” J. Opt. Soc. Am. A 10, 395–404 (1993).
[CrossRef] [PubMed]

S. Magnussen, M. W. Greenlee, J. P. Thomas, “Parallel processing in visual short-term memory,” J. Exp. Psychol. (to be published).

Kramer, P.

E. T. Davis, P. Kramer, N. Graham, “Uncertainty about spatial frequency, spatial position, or contrast of visual patterns,” Percept. Psychophys. 33, 20–28 (1983).
[CrossRef] [PubMed]

Landy, M. S.

M. S. Landy, J. R. Bergen, “Texture segregation and orientation gradient,” Vision Res. 31, 679–692 (1991).
[CrossRef] [PubMed]

Magnussen, S.

S. Magnussen, M. W. Greenlee, J. P. Thomas, “Parallel processing in visual short-term memory,” J. Exp. Psychol. (to be published).

Nguyen, K.

A. B. Watson, K. R. Nielson, A. Poirson, A. Fitzhugh, A. Bilson, K. Nguyen, A. Ahumada, “Use of raster framebuffer in vision research,” Behav. Res. Methods Instrum. Comput. 18, 587–594 (1986).
[CrossRef]

Nielson, K. R.

A. B. Watson, K. R. Nielson, A. Poirson, A. Fitzhugh, A. Bilson, K. Nguyen, A. Ahumada, “Use of raster framebuffer in vision research,” Behav. Res. Methods Instrum. Comput. 18, 587–594 (1986).
[CrossRef]

Olzak, L. A.

L. A. Olzak, J. P. Thomas, “Configural effects constrain Fourier models of pattern discrimination,” Vision Res. 32, 1885–1898 (1992).
[CrossRef] [PubMed]

L. A. Olzak, J. P. Thomas, “When orthogonal orientations are not processed independently,” Vision Res. 31, 51–57 (1991).
[CrossRef] [PubMed]

J. P. Thomas, L. A. Olzak, “Cue summation is spatial discriminations,” Vision Res. 30, 1865–1875 (1990).
[CrossRef]

L. A. Olzak, J. P. Thomas, “Seeing spatial patterns,” in Sensory Processes and Perception, Vol. 1 of Handbook of Perception and Human Performance, K. Boff, L. Kaufman, J. P. Thomas, eds. (Wiley, New York, 1986), pp. 7-1–7-56.

Poirson, A.

A. B. Watson, K. R. Nielson, A. Poirson, A. Fitzhugh, A. Bilson, K. Nguyen, A. Ahumada, “Use of raster framebuffer in vision research,” Behav. Res. Methods Instrum. Comput. 18, 587–594 (1986).
[CrossRef]

Richards, W. A.

Smith, B. G.

Sutter, A.

N. Graham, J. Beck, A. Sutter, “Nonlinear processes in spatial-frequency channel models of perceived texture segregation: effects of sign and amount of contrast,” Vision Res. 32, 719–743 (1992).
[CrossRef] [PubMed]

Tanner, W. P.

W. P. Tanner, “Physiological implications of psychophysical data,” Ann. N. Y. Acad. Sci. 89, 752–765 (1961).
[CrossRef] [PubMed]

Thomas, J. P.

M. W. Greenlee, J. P. Thomas, “Simultaneous discrimination of the spatial frequency and contrast of periodic stimuli,” J. Opt. Soc. Am. A 10, 395–404 (1993).
[CrossRef] [PubMed]

L. A. Olzak, J. P. Thomas, “Configural effects constrain Fourier models of pattern discrimination,” Vision Res. 32, 1885–1898 (1992).
[CrossRef] [PubMed]

L. A. Olzak, J. P. Thomas, “When orthogonal orientations are not processed independently,” Vision Res. 31, 51–57 (1991).
[CrossRef] [PubMed]

J. P. Thomas, L. A. Olzak, “Cue summation is spatial discriminations,” Vision Res. 30, 1865–1875 (1990).
[CrossRef]

B. G. Smith, J. P. Thomas, “Why are some spatial discriminations independent of contrast?” J. Opt. Soc. Am. A 6, 713–724 (1989).
[CrossRef] [PubMed]

J. P. Thomas, “Independent processing of suprathreshold spatial gratings as a function of their separation in spatial frequency,” J. Opt. Soc. Am. A 6, 1102–1111 (1989).
[CrossRef] [PubMed]

S. Magnussen, M. W. Greenlee, J. P. Thomas, “Parallel processing in visual short-term memory,” J. Exp. Psychol. (to be published).

L. A. Olzak, J. P. Thomas, “Seeing spatial patterns,” in Sensory Processes and Perception, Vol. 1 of Handbook of Perception and Human Performance, K. Boff, L. Kaufman, J. P. Thomas, eds. (Wiley, New York, 1986), pp. 7-1–7-56.

Watson, A. B.

A. B. Watson, K. R. Nielson, A. Poirson, A. Fitzhugh, A. Bilson, K. Nguyen, A. Ahumada, “Use of raster framebuffer in vision research,” Behav. Res. Methods Instrum. Comput. 18, 587–594 (1986).
[CrossRef]

Wilson, H. R.

Ann. N. Y. Acad. Sci. (1)

W. P. Tanner, “Physiological implications of psychophysical data,” Ann. N. Y. Acad. Sci. 89, 752–765 (1961).
[CrossRef] [PubMed]

Behav. Res. Methods Instrum. Comput. (1)

A. B. Watson, K. R. Nielson, A. Poirson, A. Fitzhugh, A. Bilson, K. Nguyen, A. Ahumada, “Use of raster framebuffer in vision research,” Behav. Res. Methods Instrum. Comput. 18, 587–594 (1986).
[CrossRef]

IEEE Trans. Patt. Analy. Mach. Vis. (1)

A. C. Bovik, M. Clark, W. S. Geisler, “Multichannel texture analysis using localized spatial filters,” IEEE Trans. Patt. Analy. Mach. Vis. 12, 55–73 (1990).
[CrossRef]

J. Opt. Soc. Am. A (4)

Percept. Psychophys. (1)

E. T. Davis, P. Kramer, N. Graham, “Uncertainty about spatial frequency, spatial position, or contrast of visual patterns,” Percept. Psychophys. 33, 20–28 (1983).
[CrossRef] [PubMed]

Vision Res. (6)

J. P. Thomas, L. A. Olzak, “Cue summation is spatial discriminations,” Vision Res. 30, 1865–1875 (1990).
[CrossRef]

L. A. Olzak, J. P. Thomas, “Configural effects constrain Fourier models of pattern discrimination,” Vision Res. 32, 1885–1898 (1992).
[CrossRef] [PubMed]

L. A. Olzak, J. P. Thomas, “When orthogonal orientations are not processed independently,” Vision Res. 31, 51–57 (1991).
[CrossRef] [PubMed]

E. T. Davis, N. Graham, “Spatial frequency uncertainty effects in the detection of visual sinusoidal gratings,” Vision Res. 21, 705–712 (1981).
[CrossRef]

M. S. Landy, J. R. Bergen, “Texture segregation and orientation gradient,” Vision Res. 31, 679–692 (1991).
[CrossRef] [PubMed]

N. Graham, J. Beck, A. Sutter, “Nonlinear processes in spatial-frequency channel models of perceived texture segregation: effects of sign and amount of contrast,” Vision Res. 32, 719–743 (1992).
[CrossRef] [PubMed]

Other (4)

N. V. S. Graham, Visual Pattern Analyzers (Oxford U. Press, New York, 1989).
[CrossRef]

L. A. Olzak, J. P. Thomas, “Seeing spatial patterns,” in Sensory Processes and Perception, Vol. 1 of Handbook of Perception and Human Performance, K. Boff, L. Kaufman, J. P. Thomas, eds. (Wiley, New York, 1986), pp. 7-1–7-56.

In theory, there is a third possible explanation for uncertainty effects when only one component of the stimulus differs from the standard: in certainty conditions the subject knows which component has the standard value and bases the judgment on a simultaneous comparison between the components; in the uncertainty conditions such a comparison is ambiguous, and the subject must rely on an absolute judgment or a comparison with a remembered standard value. However, Olzak and Thomas found that, for the fine discriminations measured in this paper, subjects do not base their judgments on relative comparisons between components even when such judgments would be more accurate.7

S. Magnussen, M. W. Greenlee, J. P. Thomas, “Parallel processing in visual short-term memory,” J. Exp. Psychol. (to be published).

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Figures (4)

Fig. 1
Fig. 1

Illustration of initial cortical representation and hypothesized second-order mechanisms. All plots show the Fourier domain in polar coordinates. A, Schematic illustration of the initial cortical representation. Each of the overlapping circles represents the sensitivity range of a single cell. B, Two hypothetical second-order mechanisms that mediate spatial frequency judgments. Each mechanism pools signals from cells tuned to a single narrow band of spatial frequencies but different orientations. The two mechanisms are tuned to different, but overlapping, frequency bands. C, Two hypothetical second-order mechanisms that mediate orientation judgments. Each pools signals from cells tuned to a single narrow band of orientations but different spatial frequencies. The two mechanisms have different, but overlapping, orientation bands.

Fig. 2
Fig. 2

Approximate representations of the standard stimuli used in A, Experiment 1, and B, Experiment 2.

Fig. 3
Fig. 3

Comparisons of d′ values in certainty and uncertainty conditions for subject JPT. A, B, Baseline condition. C, D, Test condition. sf, Spatial frequency.

Fig. 4
Fig. 4

Same as Fig. 3 but for subject JLG.

Tables (2)

Tables Icon

Table 1 Mean Performance Ratios (with Standard Errors) and Statistical Comparisons for Experiment 1

Tables Icon

Table 2 Mean Performance Ratios (with Standard Errors) and Statistical Comparisons for Experiment 2

Equations (7)

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

d c , x = Δ x / σ x
d c , y = Δ y / σ y .
z = x + y
z = a x + b y + c ,
d u , x = a Δ x / ( a 2 σ x 2 + b 2 σ y 2 ) 0.5 ,
d u , y = b Δ y / ( a 2 σ x 2 + b 2 σ y 2 ) 0.5 .
{ [ ( d u , x / d c , x ) 2 + ( d u , y / d c , y ) 2 ] / 2 } 0.5 = 2 - 0.5 .

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