Effects of luminance contrast, averaged luminance and spatial frequency on vection

An experiment was conducted to examine the influence of luminance, contrast, and spatial frequency content on saccadic eye movements. 112 pictures of natural textures from Brodatz were low-pass filtered (0.04 – 0.76 cycles deg−1) and high-pass filtered (1.91 – 19.56 cycles deg−1) and varied in luminance (low and high) and contrast (low and high), resulting in eight images per texture. Circular clippings of the central parts of the images (approximately 15% of the whole image) were used as stimuli. In the condition of bottom - up processing, the eight stimuli derived from one texture were presented for 1500 ms in a circular arrangement around the fixation cross. They were followed by a briefly presented target stimulus in the centre, which in half the trials was identical to one of the eight test stimuli. Participants had to decide whether the target stimulus was identical to any of the preceding stimuli. During a trial, their eye movements were recorded by means of a Dual-Purkinje-Image eye tracker. In the top - down condition, the target stimulus was presented in each trial prior to the display of the test stimulus. It was assumed that the priming with a target produced a top - down processing of the test stimuli. The latency and landing site of the first saccade were computed and compared between the top - down and bottom - up conditions. It is hypothesised that stimulus characteristics (luminance, contrast, and spatial frequency) play a more prominent role in bottom - up processing, while top - down processing is adjusted to the particular characteristics of the prime.

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Form Aftereffect Contingent upon a Colour Shift

Perception ◽

10.1068/p070417 ◽

1978 ◽

Vol 7 (4) ◽

pp. 417-421 ◽

Cited By ~ 4

Author(s):

Benjamin M Dawson ◽

Charles F Stromeyer

Keyword(s):

Spatial Frequency ◽

Luminance Contrast ◽

Test Field ◽

Homogeneous Test ◽

Spatially Homogeneous ◽

Rule Out

After prolonged fixation of coloured gratings of low spatial frequency, images of the gratings can be elicited up to 90 min thereafter when the colour of a spatially homogeneous test field is suddenly changed. Only adapting gratings with luminance contrast induce clear aftereffects. Control experiments rule out afterimages as an explanation of the aftereffects.

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The Sensitivity of Binocular Rivalry Suppression to Changes in Orientation Assessed by Reaction-Time and Forced-Choice Techniques

Perception ◽

10.1068/p100283 ◽

1981 ◽

Vol 10 (3) ◽

pp. 283-293 ◽

Cited By ~ 17

Author(s):

Robert P O'Shea ◽

Boris Crassini

Keyword(s):

Reaction Time ◽

Spatial Frequency ◽

Binocular Rivalry ◽

Luminance Contrast ◽

Forced Choice ◽

Field Size ◽

Correct Performance ◽

Orientation Change ◽

Choice Procedure ◽

Forced Choice Procedure

Binocular rivalry was induced between two orthogonal square-wave gratings of the same spatial frequency, luminance, contrast, and field size, presented dichoptically. One of the gratings could be instantly replaced by a third grating differing only in orientation. In one experiment subjects were required to respond as soon as an orientation change was noticed, and to withold response to catch trials (no orientation change). When orientation changes were made to the visible grating, reaction time was found to be a U-shaped function of the magnitude of orientation change. When orientation changes were made to the grating undergoing binocular-rivalry suppression, an overall increase in reaction time was found with the increase being greater for large orientation changes (an asymmetrical U-shaped function). In another experiment subjects were required to detect the direction of a change in orientation in a two-alternative forced-choice procedure. Thresholds were thus obtained for 75% correct performance. It was found that thresholds for orientation changes made to the visible and invisible fields were identical from 20° to 70° orientation change. Outside this range thresholds were higher when orientation changes were made to the field suppressed by binocular rivalry. It is argued that the orientation functions obtained in the two experiments may represent incomplete suppression of either form or transient information during binocular rivalry.

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Form-Colour Aftereffects: Selectivity to Local Luminance Contrast

Perception ◽

10.1068/p070407 ◽

1978 ◽

Vol 7 (4) ◽

pp. 407-415 ◽

Cited By ~ 21

Author(s):

Charles F Stromeyer ◽

Benjamin M Dawson

Keyword(s):

Spatial Frequency ◽

Phase Contrast ◽

Luminance Contrast ◽

Spatial Phase ◽

Black And White ◽

White Test

For long periods observers fixated low spatial frequency coloured gratings. Black and white test gratings of the same spatial frequency and orientation as the adapting gratings appeared coloured with the hue complementary to the adapting patterns when the dark test stripes fell on retinal areas previously occupied by the dark adapting stripes; no colour or very weak colour was seen when the test gratings were reversed in phase (contrast reversed). No colour aftereffects were produced with coloured gratings that lacked luminance contrast. This selectivity to the polarity of local luminance contrast can be explained by mechanisms that respond conjointly to colour and luminance contrast. The aftereffects are selective to spatial phase.

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Influence of artificially generated interocular blur difference on fusion stability under vergence stress

Journal of Eye Movement Research ◽

10.16910/jemr.12.4.4 ◽

2019 ◽

Vol 12 (4) ◽

Author(s):

Miroslav Dostalek ◽

Jan Hejda ◽

Karel Fliegel ◽

Michaela Duchackova ◽

Ladislav Dusek ◽

...

Keyword(s):

Spatial Frequency ◽

Healthy Subjects ◽

Luminance Contrast ◽

Natural Scenes ◽

Frequency Content ◽

Binocular Fusion ◽

Dominant Eye ◽

Blurred Image ◽

The Stability ◽

Mode A

The stability of fusion was evaluated by its breakage when interocular blur differences were presented under vergence demand to healthy subjects. We presumed that these blur differences cause suppression of the more blurred image (interocular blur suppression, IOBS), disrupt binocular fusion and suppressed eye leaves its forced vergent position. During dichoptic presentation of static grayscale images of natural scenes, the luminance contrast (mode B) or higher-spatial frequency content (mode C) or luminance contrast plus higher-spatial frequency content (mode A) were stepwise reduced in the image presented to the non-dominant eye. We studied the effect of these types of blur on fusion stability at various levels of the vergence demand. During the divergence demand, the fusion was disrupted with approximately half blur than during convergence. Various modes of blur influenced fusion differently. The mode C (isolated reduction of higher-spatial frequency content) violated fusion under the lowest vergence demand significantly more than either isolated or combined reduction of luminance contrast (mode B and A). According to our results, the image´s details (i.e. higher-spatial frequency content) protects binocular fusion from disruption by the lowest vergence demand.

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Neuronal response to texture- and contrast-defined boundaries in early visual cortex

Visual Neuroscience ◽

10.1017/s0952523807070113 ◽

2007 ◽

Vol 24 (1) ◽

pp. 65-77 ◽

Cited By ~ 17

Author(s):

YUNING SONG ◽

CURTIS L. BAKER

Keyword(s):

Visual Cortex ◽

Spatial Frequency ◽

Cortical Neurons ◽

Visual Cues ◽

Neuronal Response ◽

Luminance Contrast ◽

Movement Direction ◽

Natural Scenes ◽

Neural Responses ◽

Early Visual Cortex

Natural scenes contain a variety of visual cues that facilitate boundary perception (e.g., luminance, contrast, and texture). Here we explore whether single neurons in early visual cortex can process both contrast and texture cues. We recorded neural responses in cat A18 to both illusory contours formed by abutting gratings (ICs, texture-defined) and contrast-modulated gratings (CMs, contrast-defined). We found that if a neuron responded to one of the two stimuli, it also responded to the other. These neurons signaled similar contour orientation, spatial frequency, and movement direction of the two stimuli. A given neuron also exhibited similar selectivity for spatial frequency of the fine, stationary grating components (carriers) of the stimuli. These results suggest that the cue-invariance of early cortical neurons extends to different kinds of texture or contrast cues, and might arise from a common nonlinear mechanism.

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Chromaticity discrimination: effects of luminance contrast and spatial frequency

Journal of the Optical Society of America A ◽

10.1364/josaa.3.000916 ◽

1986 ◽

Vol 3 (7) ◽

pp. 916 ◽

Cited By ~ 15

Author(s):

A. E. Elsner ◽

Joel Pokorny ◽

Stephen A. Burns

Keyword(s):

Spatial Frequency ◽

Luminance Contrast

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From spatial frequency contrast to edge preponderance: the differential modulation of early visual evoked potentials by natural scene stimuli

Visual Neuroscience ◽

10.1017/s095252381100006x ◽

2011 ◽

Vol 28 (3) ◽

pp. 221-237 ◽

Cited By ~ 23

Author(s):

BRUCE C. HANSEN ◽

THEODORE JACQUES ◽

AARON P. JOHNSON ◽

DAVE ELLEMBERG

Keyword(s):

Spatial Frequency ◽

Evoked Potentials ◽

Visual Evoked Potentials ◽

Luminance Contrast ◽

Systematic Investigation ◽

Natural Scenes ◽

Natural Scene ◽

Sinusoidal Gratings ◽

Edge Content ◽

Visual Evoked

AbstractThe contrast response function of early visual evoked potentials elicited by sinusoidal gratings is known to exhibit characteristic potentials closely associated with the processes of parvocellular and magnocellular pathways. Specifically, the N1 component has been linked with parvocellular processes, while the P1 component has been linked with magnocellular processes. However, little is known regarding the response properties of the N1 and P1 components during the processing and encoding of complex (i.e., broadband) stimuli such as natural scenes. Here, we examine how established physical characteristics of natural scene imagery modulate the N1 and P1 components in humans by providing a systematic investigation of component modulation as visual stimuli are gradually built up from simple sinusoidal gratings to highly complex natural scene imagery. The results suggest that the relative dominance in signal output of the N1 and P1 components is dependent on spatial frequency (SF) luminance contrast for simple stimuli up to natural scene imagery possessing few edges. However, such a dependency shifts to a dominant N1 signal for natural scenes possessing abundant edge content and operates independently of SF luminance contrast.

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Different spatial frequency bands selectively signal for natural image statistics in the early visual system

Journal of Neurophysiology ◽

10.1152/jn.00288.2012 ◽

2012 ◽

Vol 108 (8) ◽

pp. 2160-2172 ◽

Cited By ~ 20

Author(s):

Bruce C. Hansen ◽

Aaron P. Johnson ◽

Dave Ellemberg

Keyword(s):

Spatial Frequency ◽

Broad Band ◽

Amplitude Spectrum ◽

Structural Complexity ◽

Luminance Contrast ◽

Natural Image ◽

Natural Image Statistics ◽

Natural Scene ◽

Image Statistics ◽

Neural Processes

Early visual evoked potentials (VEPs) measured in humans have recently been observed to be modulated by the image statistics of natural scene imagery. Specifically, the early VEP is dominated by a strong positivity when participants view minimally complex natural scene imagery, with the magnitude of that component being modulated by luminance contrast differences across spatial frequency (i.e., the slope of the amplitude spectrum). For scenes high in structural complexity, the early VEP is dominated by a prominent negativity that exhibits little dependency on luminance contrast. However, since natural scene imagery is broad band in terms of spatial frequency, it is not known whether the above-mentioned modulation results from a complex interaction within or between the early neural processes tuned to different bands of spatial frequency. Here, we sought to address this question by measuring early VEPs (specifically, the C1, P1, and N1 components) while human participants viewed natural scene imagery that was filtered to contain specific bands of spatial frequency information. The results show that the C1 component is largely unmodulated by the luminance statistics of natural scene imagery (being only measurable when such stimuli were made to contain high spatial frequencies). The P1 and N1, on the other hand, were observed to exhibit strong spatial frequency-dependent modulation to the luminance statistics of natural scene imagery. The results therefore suggest that the dependency of early VEPs on natural image statistics results from an interaction between the early neural processes tuned to different bands of spatial frequency.

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An Effect of Luminance Contrast on High-Spatial-Frequency Tritanopia

Perception ◽

10.1068/p5051 ◽

2006 ◽

Vol 35 (2) ◽

pp. 171-184 ◽

Cited By ~ 2

Author(s):

Alexander D Logvinenko ◽

Sara J Hutchinson

Keyword(s):

Spatial Frequency ◽

High Spatial Frequency ◽

Luminance Contrast

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