scholarly journals Color-Binding Errors During Rivalrous Suppression of Form

2009 ◽  
Vol 20 (9) ◽  
pp. 1084-1091 ◽  
Author(s):  
Sang Wook Hong ◽  
Steven K. Shevell
Keyword(s):  
Binocular Rivalry ◽  
The Other ◽  
Physical Stimulus ◽  
Physical Stimulation ◽  
Eye Color ◽  
Neural Representations ◽  
Perceptual Alternation ◽  
Different Color ◽  
Binding Errors

How does a physical stimulus determine a conscious percept? Binocular rivalry provides useful insights into this question because constant physical stimulation during rivalry causes different visual experiences. For example, presentation of vertical stripes to one eye and horizontal stripes to the other eye results in a percept that alternates between horizontal and vertical stripes. Presentation of a different color to each eye (color rivalry) produces alternating percepts of the two colors or, in some cases, a color mixture. The experiments reported here reveal a novel and instructive resolution of rivalry for stimuli that differ in both form and color: perceptual alternation between the rivalrous forms (e.g., horizontal or vertical stripes), with both eyes' colors seen simultaneously in separate parts of the currently perceived form. Thus, the colors presented to the two eyes (a) maintain their distinct neural representations despite resolution of form rivalry and (b) can bind separately to distinct parts of the perceived form.

scholarly journals Single units and conscious vision

1998 ◽  
Vol 353 (1377) ◽  
pp. 1801-1818 ◽  
Author(s):  
◽  
N. K. Logothetis
Keyword(s):  
Binocular Rivalry ◽  
Neural Activity ◽  
Visual Awareness ◽  
Physiological Data ◽  
Neural Basis ◽  
Binocular Fusion ◽  
Neural Representations ◽  
Multistable Perception ◽  
Visual Areas ◽  
Psychophysical Studies

Figures that can be seen in more than one way are invaluable tools for the study of the neural basis of visual awareness, because such stimuli permit the dissociation of the neural responses that underlie what we perceive at any given time from those forming the sensory representation of a visual pattern. To study the former type of responses, monkeys were subjected to binocular rivalry, and the response of neurons in a number of different visual areas was studied while the animals reported their alternating percepts by pulling levers. Perception–related modulations of neural activity were found to occur to different extents in different cortical visual areas. The cells that were affected by suppression were almost exclusively binocular, and their proportion was found to increase in the higher processing stages of the visual system. The strongest correlations between neural activity and perception were observed in the visual areas of the temporal lobe. A strikingly large number of neurons in the early visual areas remained active during the perceptual suppression of the stimulus, a finding suggesting that conscious visual perception might be mediated by only a subset of the cells exhibiting stimulus selective responses. These physiological findings, together with a number of recent psychophysical studies, offer a new explanation of the phenomenon of binocular rivalry. Indeed, rivalry has long been considered to be closely linked with binocular fusion and stereopsis, and the sequences of dominance and suppression have been viewed as the result of competition between the two monocular channels. The physiological data presented here are incompatible with this interpretation. Rather than reflecting interocular competition, the rivalry is most probably between the two different central neural representations generated by the dichoptically presented stimuli. The mechanisms of rivalry are probably the same as, or very similar to, those underlying multistable perception in general, and further physiological studies might reveal a much about the neural mechanisms of our perceptual organization.

scholarly journals Varying the Color of Mammography Display Improves the Detectability of Microcalcifications

2019 ◽  
pp. 1-4
Author(s):  
Akio Ogura ◽  
Akio Ogura ◽  
Fumie Maeda ◽  
Haruyuki Watanabe ◽  
Norio Hayashi ◽  
...  
Keyword(s):  
The Other ◽  
Color Scale ◽  
Eye Fatigue ◽  
Yellow Scale ◽  
Different Color ◽  
Color Scales

Purpose: This study assessed whether varying the color of the display improves the detectability of microcalcifications on mammography. Materials and Methods: The American College of Radiology (ACR) 156 mammographic phantom was imaged under three different conditions. Ten observers evaluated the depiction of 30 phantom microcalcifications presented in six color-scales: red, green, yellow, blue, and cyan. Differences in the detectability of macrocalcifications and eye and psychological fatigue among the different color scales were assessed. Results: Yellow-scale images improved the detectability of microcalcifications to a significantly greater extent than did the other colors: relative to blue and red, P < 0.01; relative to gray, green, and cyan, P < 0.05. The cyan display induced the least eye fatigue. While no difference in eye fatigue induced by the yellow and gray displays was found, displays of these colors were associated with significantly less eye fatigue than the green-scale (P < 0.01), red-scale, and blue-scale displays (P < 0.001). Conclusion: The detectability of microcalcifications on mammography can be improved by changing the color scale in which mammograms are visualized from gray to yellow.

Pleasingness vs Interestingness of Visual Stimuli with Controlled Complexity: Their Relationship to Looking Time as a Function of Exposure Time

1975 ◽  
Vol 40 (1) ◽  
pp. 3-7 ◽  
Author(s):  
Gerda Smets
Keyword(s):  
Exposure Time ◽  
Binocular Rivalry ◽  
Stimulus Pair ◽  
Significant Interaction ◽  
Visual Stimuli ◽  
The Other ◽  
Stimulus Complexity

Ss take more time to perceive interesting/displeasing stimuli than uninteresting/pleasing ones. This is consistent with the results of former experiments. However we used a different operationalization of looking time, based on binocular rivalry. Each of six stimulus pairs was presented in a stereoscope. One member of each pair was interesting but displeasing in comparison to the other member. Stimulus complexity was under control. Due to binocular rivalry Ss perceived only one pattern a time. 20 Ss were asked to indicate which pattern they actually saw by pushing two buttons. For each stimulus pair was registered how long each button was pushed during each of six successive minutes. Unlike other operationalizations this one is less dependent on S's determination of what stimulus will be looked at or for how long. It has the advantage that it is bound up more exclusively with relations of similarity and dissimilarity between stimulus elements. It allows manipulation of exposure time in a systematic and continuous way. There is no significant interaction between looking and exposure time.

What is Suppressed during Binocular Rivalry?

Perception ◽  
1980 ◽  
Vol 9 (2) ◽  
pp. 223-231 ◽  
Author(s):  
Randolph Blake ◽  
David H Westendorf ◽  
Randall Overton
Keyword(s):  
Binocular Rivalry ◽  
The Other ◽  
Dominant Eye ◽  
Prior Adaptation

To answer the question ‘What is suppressed during binocular rivalry?’ a series of three experiments was performed. In the first experiment observers viewed binocular rivalry between orthogonally oriented patterns. When the dominant and suppressed patterns were interchanged between the eyes observers continued seeing with the dominant eye, indicating that an eye, not a pattern, is suppressed during rivalry. In a second experiment it was found that a suppressed eye was able to contribute to stereopsis. A third experiment demonstrated that the predominance of an eye could be influenced by prior adaptation of the other eye, indicating that binocular mechanisms participate in the rivalry process.

Dynamics of Within-, Inter-, and Cross-Modal Attentional Modulation

2011 ◽  
Vol 105 (2) ◽  
pp. 674-686 ◽  
Author(s):  
Tetsuo Kida ◽  
Koji Inui ◽  
Emi Tanaka ◽  
Ryusuke Kakigi
Keyword(s):  
Spatial Attention ◽  
Interstimulus Interval ◽  
Temporal Dynamics ◽  
Visual Stimulation ◽  
The Other ◽  
Neural Representations ◽  
Tactile Stimuli ◽  
Sensory Modalities ◽  
The Right ◽  
Directing Attention

Numerous studies have demonstrated effects of spatial attention within single sensory modalities (within-modal spatial attention) and the effect of directing attention to one sense compared with the other senses (intermodal attention) on cortical neuronal activity. Furthermore, recent studies have been revealing that the effects of spatial attention directed to a certain location in a certain sense spread to the other senses at the same location in space (cross-modal spatial attention). The present study used magnetoencephalography to examine the temporal dynamics of the effects of within-modal and cross-modal spatial and intermodal attention on cortical processes responsive to visual stimuli. Visual or tactile stimuli were randomly presented on the left or right side at a random interstimulus interval and subjects directed attention to the left or right when vision or touch was a task-relevant modality. Sensor-space analysis showed that a response around the occipitotemporal region at around 150 ms after visual stimulation was significantly enhanced by within-modal, cross-modal spatial, and intermodal attention. A later response over the right frontal region at around 200 ms was enhanced by within-modal spatial and intermodal attention, but not by cross-modal spatial attention. These effects were estimated to originate from the occipitotemporal and lateral frontal areas, respectively. Thus the results suggest different spatiotemporal dynamics of neural representations of cross-modal attention and intermodal or within-modal attention.

Binocular rivalry between identical retinal stimuli with an induced color difference

2008 ◽  
Vol 25 (3) ◽  
pp. 361-364 ◽  
Author(s):  
SANG WOOK HONG ◽  
STEVEN K. SHEVELL
Keyword(s):  
Binocular Rivalry ◽  
Binocular Disparity ◽  
Color Difference ◽  
Color Appearance ◽  
Neural Representation ◽  
Stereoscopic Depth ◽  
Perceptual Alternation ◽  
Physically Identical ◽  
Open Question

An open question in color rivalry is whether alternation between two colors is caused by a difference in receptoral stimulation or a difference in the neural representation of color appearance. This question was examined with binocular rivalry between physically identical lights that differed in appearance due to chromatic induction. Perceptual alternation was measured between gratings of the same chromaticity; each one was presented within a different patterned surround that caused the gratings, one to each eye, to appear unequal in hue because of chromatic induction. The gratings were presented dichoptically with binocular disparity so the rivalrous gratings appeared in front of the surround. Perceptual alternation in hue was found for the two physically identical chromaticities. Stereoscopic depth also was perceived, corroborating binocular neural combination despite color rivalry (Treisman, 1962). The results show that color rivalry is resolved after color-appearance shifts caused by chromatic context, and that color rivalry does not require competing unequal cone excitations from the rivalrous stimuli.

Experimentelle Beeinflussung der Drosopterinsynthese in den Drosophila-Mutanten rosy und maroon-like

1965 ◽  
Vol 20 (4) ◽  
pp. 322-326 ◽  
Author(s):  
Ilse Schwinck
Keyword(s):  
Comparative Study ◽  
The Other ◽  
Mutant Phenotype ◽  
Eye Color ◽  
Ringer’S Solution ◽  
Incubation Solution

In a comparative study of the mutants rosy and maroon-like it is demonstrated that both mutants respond to pupal case dissection and incubation in Ringer’s solution with an increased drosopterin formation. Such induced phenocopy of eye color is enhanced further by addition of phenylalanine to the incubation solution. In contrast, the other pteridines, as well as the Malpighian tubes show the mutant phenotype. The possible interaction of drosopterin synthesis and phenylalanine oxidation is discussed.

Providing a human user artificial ability to control their eyes independently with various eye movement patterns

2012 ◽  
Vol 25 (0) ◽  
pp. 171-172
Author(s):  
Fumio Mizuno ◽  
Tomoaki Hayasaka ◽  
Takami Yamaguchi
Keyword(s):  
Eye Movements ◽  
Visual Perception ◽  
Control Systems ◽  
Eye Movement ◽  
Binocular Rivalry ◽  
Human Visual System ◽  
Visual Stimulation ◽  
The Other ◽  
Flexible Adaptation ◽  
Left And Right

Humans have the capability to flexibly adapt to visual stimulation, such as spatial inversion in which a person wears glasses that display images upside down for long periods of time (Ewert, 1930; Snyder and Pronko, 1952; Stratton, 1887). To investigate feasibility of extension of vision and the flexible adaptation of the human visual system with binocular rivalry, we developed a system that provides a human user with the artificial oculomotor ability to control their eyes independently for arbitrary directions, and we named the system Virtual Chameleon having to do with Chameleons (Mizuno et al., 2010, 2011). The successful users of the system were able to actively control visual axes by manipulating 3D sensors held by their both hands, to watch independent fields of view presented to the left and right eyes, and to look around as chameleons do. Although it was thought that those independent fields of view provided to the user were formed by eye movements control corresponding to pursuit movements on human, the system did not have control systems to perform saccadic movements and compensatory movements as numerous animals including human do. Fluctuations in dominance and suppression with binocular rivalry are irregular, but it is possible to bias these fluctuations by boosting the strength of one rival image over the other (Blake and Logothetis, 2002). It was assumed that visual stimuli induced by various eye movements affect predominance. Therefore, in this research, we focused on influenced of patterns of eye movements on visual perception with binocular rivalry, and implemented functions to produce saccadic movements in Virtual Chameleon.

Spectral sensitivities of elementary color-coded neurons in butterfly larva

1990 ◽  
Vol 64 (6) ◽  
pp. 1861-1872 ◽  
Author(s):  
T. Ichikawa
Keyword(s):  
Synergistic Effect ◽  
Compound Eye ◽  
Functional Class ◽  
The Other ◽  
White Background ◽  
Swallowtail Butterfly ◽  
Color Opponency ◽  
Distinct Color ◽  
Different Color ◽  
Excitatory Responses

1. Response properties and spectral sensitivities of a functional class of medulla neurons that received dominant input from a single stemma in the swallowtail butterfly larva were examined with regard to neutral and chromatic backgrounds. 2. Eight types of neurons were dominated by a dichromatic stemma with blue and green receptors. Six showed specific color-opponent responses mediated by two receptors on different backgrounds; one showed strong color opponency because of fairly balanced antagonistic input on the neutral (dark and white) background; the other five usually had weak or concealed color opponency on a neutral background but became strongly color opponent when appropriate chromatic illumination was present on the background. The most complex neuron gave excitatory responses on a dark background, inhibitory responses on a white background, and color-opponent responses on a chromatic (yellow) background. 3. The remaining two types of neurons dominated by the dichromatic stemma showed non-color-opponent and broad action spectra ascribable to a synergistic effect of the two classes of photoreceptors. 4. All eight types of neurons dominated by a trichromatic stemma (with UV, blue, and green receptors) were color opponent. Five showed strong color-opponent responses with the mediation of the three classes of receptors or only two (UV and green) on a neutral background. The others revealed distinct color opponency in the presence of UV or green illumination on the background. 5. The larval medulla neurons described may form parallel, elementary color-coded channels in the medulla neuropile to combine the outputs of the different color receptors in a single visual unit (stemma) into specific color-opponent signals. They probably correspond to columnar relay neurons in the medulla of the adult insects with a compound eye.

Perceived Depth in the ‘Sieve Effect’ and Exclusive Binocular Rivalry

Perception ◽  
10.1068/p5749 ◽  
2007 ◽  
Vol 36 (7) ◽  
pp. 990-1002 ◽  
Author(s):  
Kazumichi Matsumiya ◽  
Ian P Howard ◽  
Hirohiko Kaneko
Keyword(s):  
Binocular Rivalry ◽  
The Other ◽  
Stimulus Combination ◽  
Depth Probe ◽  
Sieve Effect

An impression of a surface seen through holes is created when one fuses dichoptic pairs of discs, with one member of each pair black and the other member white. This is referred to as the ‘sieve effect’. The stimulus contains no positional disparities. Howard (1995, Perception24 67–74) noted qualitatively that the sieve effect occurs when the rivalrous regions are within the range of sizes, contrasts, and relative sizes where exclusive rivalry occurs, rather than binocular lustre, stimulus combination, or dominant rivalry. This suggests that perceived depth in the sieve effect should be at a maximum when exclusive rivalry is most prominent. We used a disparity depth probe to measure the magnitude of perceived depth in the sieve effect as a function of the sizes, contrasts, and relative sizes of the rivalrous regions. We also measured the rate of exclusive rivalry of the same stimuli under the same conditions. Perceived depth and the rate of exclusive rivalry were affected in the same way by each of the three variables. Furthermore, perceived depth and the rate of exclusive rivalry were affected in the same way by changes in vergence angle, although the configuration of the stimulus surface was held constant. These findings confirm the hypothesis that the sieve effect is correlated with the incidence of exclusive rivalry.

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