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Influence of Contrast and Coherence on the Temporal Dynamics of Binocular Motion Rivalry

Levelt’s four propositions (L1–L4), which characterize the relation between changes in “stimulus strength” in the two eyes and percept alternations, are considered benchmark for binocular rivalry models. It was recently demonstrated that adaptation mutual-inhibition models of binocular rivalry captu...

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Autores principales: Platonov, Artem, Goossens, Jeroen
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3743782/
https://www.ncbi.nlm.nih.gov/pubmed/23967265
http://dx.doi.org/10.1371/journal.pone.0071931
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author Platonov, Artem
Goossens, Jeroen
author_facet Platonov, Artem
Goossens, Jeroen
author_sort Platonov, Artem
collection PubMed
description Levelt’s four propositions (L1–L4), which characterize the relation between changes in “stimulus strength” in the two eyes and percept alternations, are considered benchmark for binocular rivalry models. It was recently demonstrated that adaptation mutual-inhibition models of binocular rivalry capture L4 only in a limited range of input strengths, predicting an increase rather than a decrease in dominance durations with increasing stimulus strength for weak stimuli. This observation challenges the validity of those models, but possibly L4 itself is invalid. So far, L1–L4 have been tested mainly by varying the contrast of static stimuli, but since binocular rivalry breaks down at low contrasts, it has been difficult to study L4. To circumvent this problem, and to test if the recent revision of L2 has more general validity, we studied changes in binocular rivalry evoked by manipulating coherence of oppositely-moving random-dot stimuli in the two eyes, and compared them against the effects of stimulus contrast. Thirteen human observers participated. Both contrast and coherence manipulations in one eye produced robust changes in both eyes; dominance durations of the eye receiving the stronger stimulus increased while those of the other eye decreased, albeit less steeply. This is inconsistent with L2 but supports its revision. When coherence was augmented in both eyes simultaneously, dominance durations first increased at low coherence, and then decreased for further increases in coherence. The same held true for the alternation periods. The initial increase in dominance durations was absent in the contrast experiments, but with coherence manipulations, rivalry could be tested at much lower stimulus strengths. Thus, we found that L4, like L2, is only valid in a limited range of stimulus strengths. Outside that range, the opposite is true. Apparent discrepancies between contrast and coherence experiments could be fully reconciled with adaptation mutual-inhibition models using a simple input transfer-function.
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spelling pubmed-37437822013-08-21 Influence of Contrast and Coherence on the Temporal Dynamics of Binocular Motion Rivalry Platonov, Artem Goossens, Jeroen PLoS One Research Article Levelt’s four propositions (L1–L4), which characterize the relation between changes in “stimulus strength” in the two eyes and percept alternations, are considered benchmark for binocular rivalry models. It was recently demonstrated that adaptation mutual-inhibition models of binocular rivalry capture L4 only in a limited range of input strengths, predicting an increase rather than a decrease in dominance durations with increasing stimulus strength for weak stimuli. This observation challenges the validity of those models, but possibly L4 itself is invalid. So far, L1–L4 have been tested mainly by varying the contrast of static stimuli, but since binocular rivalry breaks down at low contrasts, it has been difficult to study L4. To circumvent this problem, and to test if the recent revision of L2 has more general validity, we studied changes in binocular rivalry evoked by manipulating coherence of oppositely-moving random-dot stimuli in the two eyes, and compared them against the effects of stimulus contrast. Thirteen human observers participated. Both contrast and coherence manipulations in one eye produced robust changes in both eyes; dominance durations of the eye receiving the stronger stimulus increased while those of the other eye decreased, albeit less steeply. This is inconsistent with L2 but supports its revision. When coherence was augmented in both eyes simultaneously, dominance durations first increased at low coherence, and then decreased for further increases in coherence. The same held true for the alternation periods. The initial increase in dominance durations was absent in the contrast experiments, but with coherence manipulations, rivalry could be tested at much lower stimulus strengths. Thus, we found that L4, like L2, is only valid in a limited range of stimulus strengths. Outside that range, the opposite is true. Apparent discrepancies between contrast and coherence experiments could be fully reconciled with adaptation mutual-inhibition models using a simple input transfer-function. Public Library of Science 2013-08-14 /pmc/articles/PMC3743782/ /pubmed/23967265 http://dx.doi.org/10.1371/journal.pone.0071931 Text en © 2013 Platonov, Goossens http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Platonov, Artem
Goossens, Jeroen
Influence of Contrast and Coherence on the Temporal Dynamics of Binocular Motion Rivalry
title Influence of Contrast and Coherence on the Temporal Dynamics of Binocular Motion Rivalry
title_full Influence of Contrast and Coherence on the Temporal Dynamics of Binocular Motion Rivalry
title_fullStr Influence of Contrast and Coherence on the Temporal Dynamics of Binocular Motion Rivalry
title_full_unstemmed Influence of Contrast and Coherence on the Temporal Dynamics of Binocular Motion Rivalry
title_short Influence of Contrast and Coherence on the Temporal Dynamics of Binocular Motion Rivalry
title_sort influence of contrast and coherence on the temporal dynamics of binocular motion rivalry
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3743782/
https://www.ncbi.nlm.nih.gov/pubmed/23967265
http://dx.doi.org/10.1371/journal.pone.0071931
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