Human Visual Acuity Measured with Colored Test Objects

Cavonius, C. R.; Schumacher, Anne W.

doi:10.1126/science.152.3726.1276

Cited by 22 publications

(10 citation statements)

References 4 publications

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“…The large receptive field sizes of Double-Opponent cells might limit the spatial resolution they could encode. Indeed, this is consistent with our lower acuity for images in which color is the only cue (Liebmann, 1926;Granger and Heurtley, 1973;De Valois and Switkes, 1983;Mullen, 1985;Livingstone and Hubel, 1987) (but see Cavonius and Schumacher, 1966). Finally, the fixed ratio of L and M input that redgreen Double-Opponent cells receive suggests that these cells establish a single chromatic axis which, in conjunction with a blue-yellow and a black-white axis, is sufficient to describe all of color space.…”

Section: The Wiring Of Double-opponent Cellssupporting

confidence: 86%

Spatial Structure of Cone Inputs to Color Cells in Alert Macaque Primary Visual Cortex (V-1)

2001

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The spatial structure of color cell receptive fields is controversial. Here, spots of light that selectively modulate one class of cones (L, M, or S, or loosely red, green, or blue) were flashed in and around the receptive fields of V-1 color cells to map the spatial structure of the cone inputs. The maps generated using these cone-isolating stimuli and an eye-position-corrected reverse correlation technique produced four findings. First, the receptive fields were Double-Opponent, an organization of spatial and chromatic opponency critical for color constancy and color contrast. Optimally stimulating both center and surround subregions with adjacent red and green spots excited the cells more than stimulating a single subregion. Second, red-green cells responded in a luminance-invariant way. For example, red-on-center cells were excited equally by a stimulus that increased L-cone activity (appearing bright red) and by a stimulus that decreased M-cone activity (appearing dark red). This implies that the opponency between L and M is balanced and argues that these cells are encoding a single chromatic axis. Third, most color cells responded to stimuli of all orientations and had circularly symmetric receptive fields. Some cells, however, showed a coarse orientation preference. This was reflected in the receptive fields as oriented Double-Opponent subregions. Fourth, red-green cells often responded to S-cone stimuli. Responses to M-and S-cone stimuli usually aligned, suggesting that these cells might be red-cyan. In summary, red-green (or red-cyan) cells, along with blue-yellow and black-white cells, establish three chromatic axes that are sufficient to describe all of color space. Three classes of cones with peak absorptions in the long (560 nm), medium (530 nm), and short (450 nm) wavelengths of light mediate the discrimination of color; they are referred to as L-, M-, and S-cones. The cones are sometimes referred to as red, green, and blue, but each cone class does not code the perception of a single color. Instead, color is mediated by an opponent process (Hering, 1964). This is reflected in the receptive fields of two classes of cells in the lateral geniculate nucleus (LGN), Type I and Type II cells (Fig. 1 A, B) (Wiesel and Hubel, 1966). Type II cells are thought to represent the retinal and geniculate origin of the perceptual blue-yellow axis. These cells have spatially simple receptive fields consisting of one region, and stimulation with different wavelengths within this region causes the cell to respond in different ways: blue-on Type II cells would be excited by blue light and suppressed by yellow light (Fig. 1 B) (Wiesel and Hubel, 1966;Dacey and Lee, 1994). Because the evidence for red-green Type II cells is paltry (Wiesel and Hubel, 1966;De Monasterio and Gouras, 1975;Dreher et al., 1976;De Monasterio, 1978) (for review, see Rodieck, 1991), Type I cells have been invoked as the origin for the red-green axis. Type I cells are chromatically opponent (Fig. 1 A), although their receptive field centers are m...

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Section: The Wiring Of Double-opponent Cellssupporting

confidence: 86%

Spatial Structure of Cone Inputs to Color Cells in Alert Macaque Primary Visual Cortex (V-1)

2001

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“…Prusky, Harker, Douglas, and Whishaw (2002) found that wild rats and some domesticated strains have a threshold of spatial resolution around 1 cycle per degree. This is comparable to the resolution of the Gigantiops ants that Wystrach and Beugnon (2009) tested in arenas-the best eyes found in ants-and an order of magnitude poorer than that found in humans, which measures in minutes (Cavonius & Schumacher, 1966). We could find no publications on the ventral stream in rats, but a division in processing object and spatial information similar to that for humans has at least been suggested for rats (Knierim, Lee, & Hargreaves, 2006).…”

Section: Critiquesupporting

confidence: 58%

25 years of research on the use of geometry in spatial reorientation: a current theoretical perspective

2013

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The purpose of this article is to review and evaluate the range of theories proposed to explain findings on the use of geometry in reorientation. We consider five key approaches and models associated with them and, in the course of reviewing each approach, five key issues. First, we take up modularity theory itself, as recently revised by Lee and Spelke (Cognitive Psychology, 61, 152-176, 2010a; Experimental Brain Research, 206, 179-188, 2010b). In this context, we discuss issues concerning the basic distinction between geometry and features. Second, we review the view-matching approach (Stürzl, Cheung, Cheng, & Zeil, Journal of Experimental Psychology: Animal Behavior Processes, 34, 1-14, 2008). In this context, we highlight the possibility of cross-species differences, as well as commonalities. Third, we review an associative theory (Miller & Shettleworth, Journal of Experimental Psychology: Animal Behavior Processes, 33, 191-212, 2007; Journal of Experimental Psychology: Animal Behavior Processes, 34, 419-422, 2008). In this context, we focus on phenomena of cue competition. Fourth, we take up adaptive combination theory (Newcombe & Huttenlocher, 2006). In this context, we focus on discussing development and the effects of experience. Fifth, we examine various neurally based approaches, including frameworks proposed by Doeller and Burgess (Proceedings of the National Academy of Sciences of the United States of America, 105, 5909-5914, 2008; Doeller, King, & Burgess, Proceedings of the National Academy of Sciences of the United States of America, 105, 5915-5920, 2008) and by Sheynikhovich, Chavarriaga, Strösslin, Arleo, and Gerstner (Psychological Review, 116, 540-566, 2009). In this context, we examine the issue of the neural substrates of spatial navigation. We conclude that none of these approaches can account for all of the known phenomena concerning the use of geometry in reorientation and clarify what the challenges are for each approach.

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“…Such effects might be explained if the medium and high spatial frequency thresholds were based on luminance artifacts in the stimulus produced by chromatic aberrations. Cavonius & Schumacher (1966), who measured acuities to chromatic gratings, did not look for colour differences in the stimulus but reported a wave-length discrimination function at 30 cycles/deg which is very unlikely to be based on hue discriminations. Another possibility which should be considered in this case is that the spectral sensitivity of the achromatic detecting mechanism changes at spatial frequencies greater than those used in the present experiment introducing brightness differences into the stimulus.…”

Section: Discussionmentioning

confidence: 99%

“…Two studies which include measurements made using blue-yellow sine or square-wave stimuli suggest CONTRAST SENSITIVITY TO CHROMATICGRATINGS an acuity greater than 20 cycles/deg (Van der Horst et al 1967;Van der Horst & Bouman, 1969). Studies which have attempted to measure acuity using isoluminant sine-or square-wave gratings of variable wave-lengths have also reported a similar range of acuity values from 20 to 30 cycles/deg (Hilz, Hupperman & Cavonius, 1974 and bar frequencies of 46 cycles/deg reported to equal luminance acuity under similar conditions (Cavonius & Schumacher, 1966). The purpose of the following calculations is to make accurate predictions of colour and luminance acuity on the basis of the new contrast sensitivity measurements obtained here.…”

Section: Comparison Of Chromatic and Luminance Acuitymentioning

confidence: 95%

The contrast sensitivity of human colour vision to red‐green and blue‐yellow chromatic gratings.

Mullen¹

1985

The Journal of Physiology

879

485

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SUMMARY1. A method ofproducing red-green and blue-yellow sinusoidal chromatic gratings is used which permits the correction of all chromatic aberrations.2. A quantitative criterion is adopted to choose the intensity match of the two colours in the stimulus: this is the intensity ratio at which contrast sensitivity for the chromatic grating differs most from the contrast sensitivity for a monochromatic luminance grating. Results show that this intensity match varies with spatial frequency and does not necessarily correspond to a luminance match between the colours.3. Contrast sensitivities to the chromatic gratings at the criterion intensity match are measured as a function of spatial frequency, using field sizes ranging from 2 to 23 deg. Both blue-yellow and red-green contrast sensitivity functions have similar low-pass characteristics, with no low-frequency attenuation even at low frequencies below 041 cycles/deg. These functions indicate that the limiting acuities based on red-green and blue-yellow colour discriminations are similar at 11 or 12 cycles/deg.4. Comparisons between contrast sensitivity functions for the chromatic and monochromatic gratings are made at the same mean luminances. Results show that, at low spatial frequencies below 0 5 cycles/deg, contrast sensitivity is greater to the chromatic gratings, consisting of two monochromatic gratings added in antiphase, than to either monochromatic grating alone. Above 0-5 cycles/deg, contrast sensitivity is greater to monochromatic than to chromatic gratings.

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Human Visual Acuity Measured with Colored Test Objects

Cited by 22 publications

References 4 publications

Spatial Structure of Cone Inputs to Color Cells in Alert Macaque Primary Visual Cortex (V-1)

Spatial Structure of Cone Inputs to Color Cells in Alert Macaque Primary Visual Cortex (V-1)

25 years of research on the use of geometry in spatial reorientation: a current theoretical perspective

The contrast sensitivity of human colour vision to red‐green and blue‐yellow chromatic gratings.

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