Nonlinear distortion of gratings at the foveal resolution limit

Sekiguchi, Nobutoshi; Williams, David R.; Packer, Orin S.

doi:10.1016/0042-6989(91)90149-y

Cited by 11 publications

(3 citation statements)

References 21 publications

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“…We have mentioned above that with fringe pattern frequencies close to the Nyquist frequency (approximately 50 -70 c͞deg in the central fovea) an unstable structure centered around fixation can be seen, which has been described by Sekiguchi et al 13 as secondary zebra stripes. They have convincingly shown that this is due to aliasing in conjunction with local luminance nonlinearity.…”

Section: Appearance Of a Sustained Fringe Pattern Near The Resolutmentioning

confidence: 68%

“…A second possible cue is suggested by the observation of Sekiguchi et al, 13 who reported seeing "secondary zebra stripes" around the Nyquist frequency. These are thought to arise (most probably) from the same local nonlinear mechanism that generates the brightness distortion product, acting in conjunction with sampling by the cone mosaic.…”

Section: B Results and Discussionmentioning

confidence: 97%

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Local luminance nonlinearity and receptor aliasing in the detection of high-frequency gratings

MacLeod

1996

J. Opt. Soc. Am. A

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Contrast sensitivity for orientation discrimination is limited to spatial frequencies below 50-60 cycles per degree by neural spatial integration, and we find that contrast sensitivity, measured using an orientation-discrimination criterion, declines sharply with increasing spatial frequencies in that range. Yet interference fringe patterns pulsed at constant mean luminance can be detected at spatial frequencies far above that resolution limit [D.R. Williams, Vision Res. 25, 195 (1985)]. This is due at least in part to aliasing by the receptor mosaic, but another possible cue is provided by nonlinear distortion, which can create spatially uniform temporal transients when a pulsed fringe pattern is presented. We investigated the contribution of these spatially unstructured distortion products to grating detection by superimposing the pulsed fringe patterns on a randomly flickering uniform field. This manipulation has almost no effect on contrast sensitivity well below the resolution limit. Just above the resolution limit, however, the random luminance mask greatly elevates the fringe pattern detection threshold, suggesting that spatially unstructured cues provide the basis for detection in this range. At still higher fringe pattern frequencies, which approximately match the cone mosaic, the random luminance flicker again becomes ineffective for some observers, creating a clear secondary peak in contrast sensitivity in the flicker mask condition, which is presumably due to spatially structured cues provided by aliasing with the cone mosaic. The aliasing peak is still more clearly demarcated if the subject sets contrast thresholds for the perception of pattern as such. The contrast sensitivity function then has a notch or gap between the normal sensitivity range and the aliasing range. Apparently, in the unmasked case, spatially uniform cues (changes in overall color and brightness) bridge this gap.

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Section: Appearance Of a Sustained Fringe Pattern Near The Resolutmentioning

confidence: 68%

Section: B Results and Discussionmentioning

confidence: 97%

Local luminance nonlinearity and receptor aliasing in the detection of high-frequency gratings

MacLeod

1996

J. Opt. Soc. Am. A

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“…The method has also been used to explore the relative contributions of the optical and neural systems to the reduced resolution found in the retinal periphery (Green, 1970a;Enoch and Hope, 1973;Frisen and Glansholm, 1975), the optical and neural changes with age (Morrison and McGrath, 1985), the visibility of isoluminant gratings and the sampling density of neurons that mediate colour vision (Sekiguchi et al, 1993a,b) and non-linearities in the visual system (Burton, 1973;Macleod etal., 1992). Observation of aliasing effects between the fringes and the retinal mosaic in the central and peripheral retina has given valuable new information on spatial arrangement of the retinal receptors (Williams 1985(Williams , 1988(Williams , 1992Thibos etal., 1987a, b;Sekiguchi et al, 1991;Anderson et al, 1992). A further area of basic investigation has been the oblique effect and meridional amblyopia, where the use of the fringes has convincingly demonstrated that the origins of these phenomena lie in the retina and or the higher visual pathways (Campbell etal., 1966;Mitchell etal., 1967Mitchell etal., , 1969, rather than in residual uncorrected optical errors.…”

Section: Commentarymentioning

confidence: 99%

Yves Le Grand and the assessment of retinal acuity using interference fringes

Charman¹,

Simonet²

1997

Oph Phys Optics

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Just over sixty years ago, Yves Le Grand's article 'Sur la mesure de I'acuite visuelle au moyen de franges d'interference' (C. R. Acad. Sci. Paris 200: 490-491; 1935) was published. A translation of this important article into English is given and a commentary discusses the application of the interference fringe method to the study of the ocular modulation transfer function, the spatial arrangement of retinal receptors and the potential acuity of cataract patients.

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