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Evidence for a common mechanism of spatial attention and visual awareness: Towards construct validity of pseudoneglect

Present knowledge of attention and awareness centres on deficits in patients with right brain damage who show severe forms of inattention to the left, called spatial neglect. Yet the functions that are lost in neglect are poorly understood. In healthy people, they might produce “pseudoneglect”—subtl...

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Autores principales: Chen, Jiaqing, Kaur, Jagjot, Abbas, Hana, Wu, Ming, Luo, Wenyi, Osman, Sinan, Niemeier, Matthias
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6405131/
https://www.ncbi.nlm.nih.gov/pubmed/30845258
http://dx.doi.org/10.1371/journal.pone.0212998
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author Chen, Jiaqing
Kaur, Jagjot
Abbas, Hana
Wu, Ming
Luo, Wenyi
Osman, Sinan
Niemeier, Matthias
author_facet Chen, Jiaqing
Kaur, Jagjot
Abbas, Hana
Wu, Ming
Luo, Wenyi
Osman, Sinan
Niemeier, Matthias
author_sort Chen, Jiaqing
collection PubMed
description Present knowledge of attention and awareness centres on deficits in patients with right brain damage who show severe forms of inattention to the left, called spatial neglect. Yet the functions that are lost in neglect are poorly understood. In healthy people, they might produce “pseudoneglect”—subtle biases to the left found in various tests that could complement the leftward deficits in neglect. But pseudoneglect measures are poorly correlated. Thus, it is unclear whether they reflect anything but distinct surface features of the tests. To probe for a common mechanism, here we asked whether visual noise, known to increase leftward biases in the grating-scales task, has comparable effects on other measures of pseudoneglect. We measured biases using three perceptual tasks that require judgments about size (landmark task), luminance (greyscales task) and spatial frequency (grating-scales task), as well as two visual search tasks that permitted serial and parallel search or parallel search alone. In each task, we randomly selected pixels of the stimuli and set them to random luminance values, much like a poor TV signal. We found that participants biased their perceptual judgments more to the left with increasing levels of noise, regardless of task. Also, noise amplified the difference between long and short lines in the landmark task. In contrast, biases during visual searches were not influenced by noise. Our data provide crucial evidence that different measures of perceptual pseudoneglect, but not exploratory pseudoneglect, share a common mechanism. It can be speculated that this common mechanism feeds into specific, right-dominant processes of global awareness involved in the integration of visual information across the two hemispheres.
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spelling pubmed-64051312019-03-17 Evidence for a common mechanism of spatial attention and visual awareness: Towards construct validity of pseudoneglect Chen, Jiaqing Kaur, Jagjot Abbas, Hana Wu, Ming Luo, Wenyi Osman, Sinan Niemeier, Matthias PLoS One Research Article Present knowledge of attention and awareness centres on deficits in patients with right brain damage who show severe forms of inattention to the left, called spatial neglect. Yet the functions that are lost in neglect are poorly understood. In healthy people, they might produce “pseudoneglect”—subtle biases to the left found in various tests that could complement the leftward deficits in neglect. But pseudoneglect measures are poorly correlated. Thus, it is unclear whether they reflect anything but distinct surface features of the tests. To probe for a common mechanism, here we asked whether visual noise, known to increase leftward biases in the grating-scales task, has comparable effects on other measures of pseudoneglect. We measured biases using three perceptual tasks that require judgments about size (landmark task), luminance (greyscales task) and spatial frequency (grating-scales task), as well as two visual search tasks that permitted serial and parallel search or parallel search alone. In each task, we randomly selected pixels of the stimuli and set them to random luminance values, much like a poor TV signal. We found that participants biased their perceptual judgments more to the left with increasing levels of noise, regardless of task. Also, noise amplified the difference between long and short lines in the landmark task. In contrast, biases during visual searches were not influenced by noise. Our data provide crucial evidence that different measures of perceptual pseudoneglect, but not exploratory pseudoneglect, share a common mechanism. It can be speculated that this common mechanism feeds into specific, right-dominant processes of global awareness involved in the integration of visual information across the two hemispheres. Public Library of Science 2019-03-07 /pmc/articles/PMC6405131/ /pubmed/30845258 http://dx.doi.org/10.1371/journal.pone.0212998 Text en © 2019 Chen et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Chen, Jiaqing
Kaur, Jagjot
Abbas, Hana
Wu, Ming
Luo, Wenyi
Osman, Sinan
Niemeier, Matthias
Evidence for a common mechanism of spatial attention and visual awareness: Towards construct validity of pseudoneglect
title Evidence for a common mechanism of spatial attention and visual awareness: Towards construct validity of pseudoneglect
title_full Evidence for a common mechanism of spatial attention and visual awareness: Towards construct validity of pseudoneglect
title_fullStr Evidence for a common mechanism of spatial attention and visual awareness: Towards construct validity of pseudoneglect
title_full_unstemmed Evidence for a common mechanism of spatial attention and visual awareness: Towards construct validity of pseudoneglect
title_short Evidence for a common mechanism of spatial attention and visual awareness: Towards construct validity of pseudoneglect
title_sort evidence for a common mechanism of spatial attention and visual awareness: towards construct validity of pseudoneglect
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6405131/
https://www.ncbi.nlm.nih.gov/pubmed/30845258
http://dx.doi.org/10.1371/journal.pone.0212998
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