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Asymmetrical interference between number and item size perception provides evidence for a domain specific impairment in dyscalculia
Dyscalculia, a specific learning disability that impacts arithmetical skills, has previously been associated to a deficit in the precision of the system that estimates the approximate number of objects in visual scenes (the so called ‘number sense’ system). However, because in tasks involving numero...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6294370/ https://www.ncbi.nlm.nih.gov/pubmed/30550549 http://dx.doi.org/10.1371/journal.pone.0209256 |
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author | Castaldi, Elisa Mirassou, Anne Dehaene, Stanislas Piazza, Manuela Eger, Evelyn |
author_facet | Castaldi, Elisa Mirassou, Anne Dehaene, Stanislas Piazza, Manuela Eger, Evelyn |
author_sort | Castaldi, Elisa |
collection | PubMed |
description | Dyscalculia, a specific learning disability that impacts arithmetical skills, has previously been associated to a deficit in the precision of the system that estimates the approximate number of objects in visual scenes (the so called ‘number sense’ system). However, because in tasks involving numerosity comparisons dyscalculics’ judgements appears disproportionally affected by continuous quantitative dimensions (such as the size of the items), an alternative view linked dyscalculia to a domain-general difficulty in inhibiting task-irrelevant responses. To arbitrate between these views, we evaluated the degree of reciprocal interference between numerical and non-numerical quantitative dimensions in adult dyscalculics and matched controls. We used a novel stimulus set orthogonally varying in mean item size and numerosity, putting particular attention into matching both features’ perceptual discriminability. Participants compared those stimuli based on each of the two dimensions. While control subjects showed no significant size interference when judging numerosity, dyscalculics’ numerosity judgments were strongly biased by the unattended size dimension. Importantly however, both groups showed the same degree of interference from the unattended dimension when judging mean size. Moreover, only the ability to discard the irrelevant size information when comparing numerosity (but not the reverse) significantly predicted calculation ability across subjects. Overall, our results show that numerosity discrimination is less prone to interference than discrimination of another quantitative feature (mean item size) when the perceptual discriminability of these features is matched, as here in control subjects. By quantifying, for the first time, dyscalculic subjects’ degree of interference on another orthogonal dimension of the same stimuli, we are able to exclude a domain-general inhibition deficit as explanation for their poor / biased numerical judgement. We suggest that enhanced reliance on non-numerical cues during numerosity discrimination can represent a strategy to cope with a less precise number sense. |
format | Online Article Text |
id | pubmed-6294370 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-62943702018-12-28 Asymmetrical interference between number and item size perception provides evidence for a domain specific impairment in dyscalculia Castaldi, Elisa Mirassou, Anne Dehaene, Stanislas Piazza, Manuela Eger, Evelyn PLoS One Research Article Dyscalculia, a specific learning disability that impacts arithmetical skills, has previously been associated to a deficit in the precision of the system that estimates the approximate number of objects in visual scenes (the so called ‘number sense’ system). However, because in tasks involving numerosity comparisons dyscalculics’ judgements appears disproportionally affected by continuous quantitative dimensions (such as the size of the items), an alternative view linked dyscalculia to a domain-general difficulty in inhibiting task-irrelevant responses. To arbitrate between these views, we evaluated the degree of reciprocal interference between numerical and non-numerical quantitative dimensions in adult dyscalculics and matched controls. We used a novel stimulus set orthogonally varying in mean item size and numerosity, putting particular attention into matching both features’ perceptual discriminability. Participants compared those stimuli based on each of the two dimensions. While control subjects showed no significant size interference when judging numerosity, dyscalculics’ numerosity judgments were strongly biased by the unattended size dimension. Importantly however, both groups showed the same degree of interference from the unattended dimension when judging mean size. Moreover, only the ability to discard the irrelevant size information when comparing numerosity (but not the reverse) significantly predicted calculation ability across subjects. Overall, our results show that numerosity discrimination is less prone to interference than discrimination of another quantitative feature (mean item size) when the perceptual discriminability of these features is matched, as here in control subjects. By quantifying, for the first time, dyscalculic subjects’ degree of interference on another orthogonal dimension of the same stimuli, we are able to exclude a domain-general inhibition deficit as explanation for their poor / biased numerical judgement. We suggest that enhanced reliance on non-numerical cues during numerosity discrimination can represent a strategy to cope with a less precise number sense. Public Library of Science 2018-12-14 /pmc/articles/PMC6294370/ /pubmed/30550549 http://dx.doi.org/10.1371/journal.pone.0209256 Text en © 2018 Castaldi 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 Castaldi, Elisa Mirassou, Anne Dehaene, Stanislas Piazza, Manuela Eger, Evelyn Asymmetrical interference between number and item size perception provides evidence for a domain specific impairment in dyscalculia |
title | Asymmetrical interference between number and item size perception provides evidence for a domain specific impairment in dyscalculia |
title_full | Asymmetrical interference between number and item size perception provides evidence for a domain specific impairment in dyscalculia |
title_fullStr | Asymmetrical interference between number and item size perception provides evidence for a domain specific impairment in dyscalculia |
title_full_unstemmed | Asymmetrical interference between number and item size perception provides evidence for a domain specific impairment in dyscalculia |
title_short | Asymmetrical interference between number and item size perception provides evidence for a domain specific impairment in dyscalculia |
title_sort | asymmetrical interference between number and item size perception provides evidence for a domain specific impairment in dyscalculia |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6294370/ https://www.ncbi.nlm.nih.gov/pubmed/30550549 http://dx.doi.org/10.1371/journal.pone.0209256 |
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