Spatial reconstruction of signals from short-wavelength cones

Brainard, David H.; Williams, David R.

doi:10.1016/0042-6989(93)90063-3

Cited by 14 publications

(13 citation statements)

References 35 publications

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“…10 The regular arrangement of SWS cones was generally considered to optimize the spatial sampling quality of the SWS cone array. 8,14 Recent results suggest that a regular array of SWS cones may not be a ubiquitous feature of the primate retina. In two nocturnal primates, the owl monkey Aotus trivirgatus 15 and the prosimian bush baby Otolemur crassicaudatis, 16 there are no functional SWS cones at all.…”

Section: Introductionmentioning

confidence: 99%

Spatial order in short-wavelength-sensitive cone photoreceptors: a comparative study of the primate retina

et al. 2000

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We compared the spatial distribution of short-wavelength-sensitive (SWS or blue) cone photoreceptors in the retinas of eight primate species. The regularity of the SWS cone array was quantified with a statistic (packing factor) that varies between a random distribution (0) and a triangular array (1). We find wide variability among species, with packing factors varying between 0.06 and 0.3. The SWS cone array in at least two New World monkey species is indistinguishable from a random array. The SWS cone density gradient across the retina was measured in the capuchin monkey Cebus apella and the squirrel monkey Saimiri sciureus. Both species show a peak density of 5,000-8,000 cells/mm2 at the fovea and a 50-fold central-peripheral density gradient. In contrast to the wide variation in local regularity, the spatial density and the topography of SWS cones are well preserved across primates.

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Section: Introductionmentioning

confidence: 99%

Spatial order in short-wavelength-sensitive cone photoreceptors: a comparative study of the primate retina

et al. 2000

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“…The protective effect of optical blur was bypassed in Williams' experiments by pharmacologically paralyzing accommodation and bringing the monochromatic short-wavelength stimulus into good focus. S cone aliasing may also be obtained if laser interferometry is used to produce a high-contrast, high-spatial frequency stimulus that isolates the S cones (Brainard & Williams 1992). The fact that chromatic aberration in the optics of the eye could protect human vision from S cone aliasing artifacts was first noted by Yellott and colleagues (1984).…”

Section: Spatiochromatic Aliasing S Cone Submosaic Aliasingmentioning

confidence: 99%

“…The two sinusoidal patterns have the same value at each location at which there is a cone and differ only at the locations between cones: They produce the same isomerization rates for all of the cones in the mosaic and are spatial aliases of one another. Panel reproduced with permission from figure 1 in Brainard & Williams (1992). Copyright c 1992 Elsevier.…”

Section: Spatiochromatic Aliasing S Cone Submosaic Aliasingmentioning

confidence: 99%

Color and the Cone Mosaic

Brainard

2015

Annu. Rev. Vis. Sci.

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Vision is limited by the measurements taken by the cone photoreceptors. To provide useful perceptual representations, the brain must go beyond the measurements and make inferences about the scene being viewed. This article considers the first stages of spatiochromatic vision. We show how spatial and chromatic information become intertwined by the optics of the eye and because of the structure of the retinal cone mosaic, and we consider the consequent implications for perception. Because there is at most one cone at each retinal location, the standard treatment of human trichromacy does not apply at fine spatial scales. Rather, trichromacy results from a perceptual inference based on measurements from cones of different classes at different locations. Our treatment emphasizes linking physics, biology, and computation with the goal of providing a framework for a larger understanding of how the brain interprets photoreceptor excitations to see objects and their properties.

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“…Stoner, 2002;Field, Hayes, & Hess, 1993;Kellman & Shipley, 1991;Singh & Fulvio, 2005). Interpolation also arises in filling in the blind spot and angioscotomas, and in estimating the stimulus between the image samples taken by the photoreceptors (Brainard & Williams, 1993;Williams, MacLeod, & Hayhoe, 1981).…”

Section: Introductionmentioning

confidence: 99%

Humans make efficient use of natural image statistics when performing spatial interpolation

2013

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Visual systems learn through evolution and experience over the lifespan to exploit the statistical structure of natural images when performing visual tasks. Understanding which aspects of this statistical structure are incorporated into the human nervous system is a fundamental goal in vision science. To address this goal, we measured human ability to estimate the intensity of missing image pixels in natural images. Human estimation accuracy is compared with various simple heuristics (e.g., local mean) and with optimal observers that have nearly complete knowledge of the local statistical structure of natural images. Human estimates are more accurate than those of simple heuristics, and they match the performance of an optimal observer that knows the local statistical structure of relative intensities (contrasts). This optimal observer predicts the detailed pattern of human estimation errors and hence the results place strong constraints on the underlying neural mechanisms. However, humans do not reach the performance of an optimal observer that knows the local statistical structure of the absolute intensities, which reflect both local relative intensities and local mean intensity. As predicted from a statistical analysis of natural images, human estimation accuracy is negligibly improved by expanding the context from a local patch to the whole image. Our results demonstrate that the human visual system exploits efficiently the statistical structure of natural images.

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Spatial reconstruction of signals from short-wavelength cones

Cited by 14 publications

References 35 publications

Spatial order in short-wavelength-sensitive cone photoreceptors: a comparative study of the primate retina

Spatial order in short-wavelength-sensitive cone photoreceptors: a comparative study of the primate retina

Color and the Cone Mosaic

Humans make efficient use of natural image statistics when performing spatial interpolation

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