Binocular summation of chromatic changes as measured by visual reaction time

Jiménez, José María López; Medina, José M.; Barco, Luis Jiménez del; Díaz, José A.

doi:10.3758/bf03194563

Cited by 21 publications

(37 citation statements)

References 31 publications

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“…Nevertheless, further work is needed to address the influence of these factors, taking into account the transient and sustained components of the pupil response, 20,48 VRT 29 and the lower binocular summation values found at suprathreshold isoluminance. 31 The discrepancy between our results on binocular summation at suprathreshold and those reported by Collier 11 and Campbell & Green 13 at the threshold, can be explained by assuming that, at the threshold, these mechanisms present no significant activity, as might occur under suprathreshold conditions. It noteworthy that Dinse and Krüger 49 found in peristriate cortical regions, where eye control is processed, [4][5][6]41 signal-to-noise thresholds higher than near and striate areas.…”

Section: Discussioncontrasting

confidence: 82%

“…Stereoacuity and maximum disparity could be considered normal with respect to values provided by a Wheatstone stereoscope in previous experiments in which both authors also participated. 30,31 No patient has pre-existing abnormal conditions that might affect contrast sensitivity or pupil size (cataracts, glaucoma, diabetes, corneal or neuro-opthalmic diseases).…”

Section: Subjectsmentioning

confidence: 99%

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The effect of pupil size on binocular summation at suprathreshold conditions

Medina

Jiménez

Barco

2003

Current Eye Research

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Purpose. To determine the influence of retinal illuminance on monocular or binocular visual reaction time (VRT).Methods. On two normal subjects, uniform circular stimuli were presented with respect to a reference stimulus at the fovea under suprathreshold conditions, and the detection of positive and negative luminance variations was recorded. Binocular and monocular reaction times were measured (by the index finger pressing on a mouse key) for viewing with both natural and artificial pupils.Results. Binocular reaction times were shorter than monocular reaction times; nevertheless, this binocular-summation effect was less marked in trials with the artificial pupil. Analyses of binocular-summation ratios for contrast changes for both pupil types indicated maximum and minimum binocular-saturation values depending on contrast variations in both positive and negative luminance changes.Conclusions. Binocular summation can be influenced by pupil size under suprathreshold conditions. Results are discussed in terms of retinal illuminance and cortical pupil response mechanisms.

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Section: Discussioncontrasting

confidence: 82%

Section: Subjectsmentioning

confidence: 99%

The effect of pupil size on binocular summation at suprathreshold conditions

Medina

Jiménez

Barco

2003

Current Eye Research

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“…However, one female subject withdrew from the study due to relocation and was replaced. The mean age of the seven women was 26.1 years (range, [22][23][24][25][26][27][28][29][30][31][32][33][34] and of the six men was 31.7 years (range, 24 -39).…”

Section: Subjectsmentioning

confidence: 99%

“…This finding conflicts with one recent report 31 but is in accord with others. [32][33][34][35] For normal trichromats, R-G thresholds in Table 1 approximate the semiminor axes of corresponding color ellipses and the Y-B thresholds approximate the semimajor axes. Thus, while monocular axes may not appear much longer than binocular axes, they may represent substantial increases in ellipse area and considerable net loss of color sensitivity.…”

Section: Effect Of Mild Hypoxia On Chromatic Sensitivity 823mentioning

confidence: 99%

Mild Hypoxia Impairs Chromatic Sensitivity in the Mesopic Range

Connolly

Barbur

Hosking

et al. 2008

Invest. Ophthalmol. Vis. Sci.

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“…Although the dependence of RT to chromatic contrast and spatial summation has been widely studied [56][57][58][59][60][61][62][63][64], previous RT studies have taken the average mean response from a few static experimental conditions. This has ignored the presence of correlations or memory effects.…”

Section: Introductionmentioning

confidence: 99%

1/f noise in human color vision: the role of S-cone signals

Medina

Díaz

2012

J. Opt. Soc. Am. A

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We examine the functional role of S-cone signals on reaction time (RT) variability in human color vision. Stimuli were selected along red-green and blue-yellow cardinal directions and at random directions in the isoluminant plane of the color space. Trial-to-trial RT variability was not statistically independent but correlated across experimental conditions and exhibited 1/f noise spectra with an exponent close to unity in most of the cases. Regarding contrast coding, 1/f noise for random chromatic stimuli at isoluminance was similar to that for achromatic stimuli, thus suggesting that S-cone signals reduce variability of higher order color mechanisms. If we regard spatial coding, the effect of S-cone density in the retina on RT variability was investigated. The magnitude of 1/f noise at 16 min of arc (S-cone free zone) was higher than at 90 min of arc in the blue-yellow channel, and it was similar for the red-green channel. The results suggest that S-cone signals are beneficial and they modulate 1/f noise spectra at postreceptoral stages. The implications related to random multiplicative processes as a possible source of 1/f noise and the optimal information processing in color vision are discussed.

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Binocular summation of chromatic changes as measured by visual reaction time

Cited by 21 publications

References 31 publications

The effect of pupil size on binocular summation at suprathreshold conditions

The effect of pupil size on binocular summation at suprathreshold conditions

Mild Hypoxia Impairs Chromatic Sensitivity in the Mesopic Range

1/f noise in human color vision: the role of S-cone signals

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