Contrast Sensitivity of the Human Eye for Square-Wave Gratings

Schober, H.; Hilz, R.

doi:10.1364/josa.55.001086

Cited by 76 publications

(15 citation statements)

References 8 publications

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“…It has been known for decades that temporal integration in the human visual system is longer for high SF stimuli (Schober and Hilz, 1965;Nachmias, 1967;Vassilev and Mitov, 1976;Breitmeyer and Ganz, 1977), and recently it was suggested that this involves slower processing in cortical mechanisms tuned for high SF (Vassilev et al, 2002).…”

Section: Sf and Temporal Integrationmentioning

confidence: 99%

Adaptive Temporal Integration of Motion in Direction-Selective Neurons in Macaque Visual Cortex

Bair¹,

Movshon²

2004

J. Neurosci.

123

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Direction-selective neurons in the primary visual cortex (V1) and the extrastriate motion area MT/V5 constitute a critical channel that links early cortical mechanisms of spatiotemporal integration to downstream signals that underlie motion perception. We studied how temporal integration in direction-selective cells depends on speed, spatial frequency (SF), and contrast using randomly moving sinusoidal gratings and spike-triggered average (STA) analysis. The window of temporal integration revealed by the STAs varied substantially with stimulus parameters, extending farther back in time for slow motion, high SF, and low contrast. At low speeds and high SF, STA peaks were larger, indicating that a single spike often conveyed more information about the stimulus under conditions in which the mean firing rate was very low. The observed trends were similar in V1 and MT and offer a physiological correlate for a large body of psychophysical data on temporal integration. We applied the same visual stimuli to a model of motion detection based on oriented linear filters (a motion energy model) that incorporated an integrate-and-fire mechanism and found that it did not account for the neuronal data. Our results show that cortical motion processing in V1 and in MT is highly nonlinear and stimulus dependent. They cast considerable doubt on the ability of simple oriented filter models to account for the output of direction-selective neurons in a general manner. Finally, they suggest that spike rate tuning functions may miss important aspects of the neural coding of motion for stimulus conditions that evoke low firing rates.

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Section: Sf and Temporal Integrationmentioning

confidence: 99%

Adaptive Temporal Integration of Motion in Direction-Selective Neurons in Macaque Visual Cortex

Bair¹,

Movshon²

2004

J. Neurosci.

123

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“…The occurrence of higher amplitudes than .04 for the 5 cps condition is just the reverse-very infrequent in destroyers and common on carriers. 5 Thus, it is expected that amplitudes at least double those used here will be encountered at sea. Unaided acuity cannot be expected to deteriorate under these conditions: the target sizes required for resolution are too gross compared with the maximum amplitude of vibration.…”

Section: Da /Grid Bar Widthmentioning

confidence: 80%

“…* These passive, direct view systems employ image-intensifier tubes which amplify the natural illumination by factors up to 100,000. Designed to improve the ability of human beings to see under conditions of inadequate illumination, as may be encountered at night, they operate most efficiently from 10* 5 to 10" 3 foot-candles; these levels cover the range of natural illuminations from approximately quarter moon to overcast starlight. One report comparing the effectiveness of the 10° Starlight Scope to that of 7x50 binoculars and unaided vision indicates that visual sighting-ranges from three to ten times that of the binoculars may be obtained with the scope.…”

Section: Introductionmentioning

confidence: 99%

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The Effect of Vibration on Performance With Electro-Optical Aids to Night Vision

Kinney¹,

Luria²,

Markowitz³

1969

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“…It is typically invoked to account for the increased attenuation of contrast sensitivity when a stimulus is low in both spatial and temporal frequency (e.g., Kelly, 1969;Nachmias, 1967;Ratliff, Knight, & Graham, 1969;Ratliff, Knight, Toyoda, & Hartline, 1967;Robson, 1966;Schober & Hilz, 1965).…”

Section: Determination Of the Late Filter Shapesmentioning

confidence: 99%

Color and brightness encoded in a common L- and M-cone pathway with expansive and compressive nonlinearities

Stockman¹,

Petrova²,

Henning³

2014

Journal of Vision

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Lights near 560 nm appear brighter when flickered, whereas lights near 520 or 650 nm appear yellower. Both effects are consistent with signal distortion within the visual pathway-brightness changes at an expansive nonlinearity, and hue shifts at a compressive one. We previously manipulated the distortion products generated by each nonlinearity to extract the temporal properties of stages of the L-and M-cone pathways that signal brightness and color before (early stages) and after (late stages) each nonlinearity. We find that the attenuation characteristics of the early and late stages are virtually identical in both pathways: The early temporal stage acts like a band-pass filter peaking at 10-15 Hz, while the late stage acts like low-pass filter with a cut-off frequency near 3 Hz. We propose a physiologically relevant model that accounts for the filter shapes and incorporates both nonlinearities within a common parvocellular pathway. The shape of the early band-pass filter is consistent with antagonism between center signals and more sluggish and delayed surround signals, while the late filter is consistent with a simple two-stage low-pass filter. Modeling suggests that the brightness change and hue shift are both initially caused by the half-wave rectification and partition of signals into ON and OFF components. However, the hue shift is probably caused by the additional effects of a later nonlinearity that compresses chromatic red and green signals. Plausible sites for the expansive half-wave rectifying nonlinearity are after surround antagonism, possibly from horizontal cells, but the compressive nonlinearity is likely to be after the late filter.

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Contrast Sensitivity of the Human Eye for Square-Wave Gratings

Cited by 76 publications

References 8 publications

Adaptive Temporal Integration of Motion in Direction-Selective Neurons in Macaque Visual Cortex

Adaptive Temporal Integration of Motion in Direction-Selective Neurons in Macaque Visual Cortex

The Effect of Vibration on Performance With Electro-Optical Aids to Night Vision

Color and brightness encoded in a common L- and M-cone pathway with expansive and compressive nonlinearities

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