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Interpreting local visual features as a global shape requires awareness
How the brain constructs a coherent representation of the environment from noisy visual input remains poorly understood. Here, we explored whether awareness of the stimulus plays a role in the integration of local features into a representation of global shape. Participants were primed with a shape...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The Royal Society
2011
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3107621/ https://www.ncbi.nlm.nih.gov/pubmed/21147801 http://dx.doi.org/10.1098/rspb.2010.1909 |
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author | Schwarzkopf, D. Samuel Rees, Geraint |
author_facet | Schwarzkopf, D. Samuel Rees, Geraint |
author_sort | Schwarzkopf, D. Samuel |
collection | PubMed |
description | How the brain constructs a coherent representation of the environment from noisy visual input remains poorly understood. Here, we explored whether awareness of the stimulus plays a role in the integration of local features into a representation of global shape. Participants were primed with a shape defined either by position or orientation cues, and performed a shape-discrimination task on a subsequently presented probe shape. Crucially, the probe could either be defined by the same or different cues as the prime, which allowed us to distinguish the effect of priming by local features and global shape. We found a robust priming benefit for visible primes, with response times being faster when the probe and prime were the same shape, regardless of the defining cue. However, rendering the prime invisible uncovered a dissociation: position-defined primes produced behavioural benefit only for probes of the same cue type. Surprisingly, orientation-defined primes afforded an enhancement only for probes of the opposite cue. In further experiments, we showed that the effect of priming was confined to retinotopic coordinates and that there was no priming effect by invisible orientation cues in an orientation-discrimination task. This explains the absence of priming by the same cue in our shape-discrimination task. In summary, our findings show that while in the absence of awareness orientation signals can recruit retinotopic circuits (e.g. intrinsic lateral connections), conscious processing is necessary to interpret local features as global shape. |
format | Online Article Text |
id | pubmed-3107621 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2011 |
publisher | The Royal Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-31076212011-06-09 Interpreting local visual features as a global shape requires awareness Schwarzkopf, D. Samuel Rees, Geraint Proc Biol Sci Research Articles How the brain constructs a coherent representation of the environment from noisy visual input remains poorly understood. Here, we explored whether awareness of the stimulus plays a role in the integration of local features into a representation of global shape. Participants were primed with a shape defined either by position or orientation cues, and performed a shape-discrimination task on a subsequently presented probe shape. Crucially, the probe could either be defined by the same or different cues as the prime, which allowed us to distinguish the effect of priming by local features and global shape. We found a robust priming benefit for visible primes, with response times being faster when the probe and prime were the same shape, regardless of the defining cue. However, rendering the prime invisible uncovered a dissociation: position-defined primes produced behavioural benefit only for probes of the same cue type. Surprisingly, orientation-defined primes afforded an enhancement only for probes of the opposite cue. In further experiments, we showed that the effect of priming was confined to retinotopic coordinates and that there was no priming effect by invisible orientation cues in an orientation-discrimination task. This explains the absence of priming by the same cue in our shape-discrimination task. In summary, our findings show that while in the absence of awareness orientation signals can recruit retinotopic circuits (e.g. intrinsic lateral connections), conscious processing is necessary to interpret local features as global shape. The Royal Society 2011-07-22 2010-12-08 /pmc/articles/PMC3107621/ /pubmed/21147801 http://dx.doi.org/10.1098/rspb.2010.1909 Text en This Journal is © 2010 The Royal Society http://creativecommons.org/licenses/by/3.0/ 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 work is properly cited. |
spellingShingle | Research Articles Schwarzkopf, D. Samuel Rees, Geraint Interpreting local visual features as a global shape requires awareness |
title | Interpreting local visual features as a global shape requires awareness |
title_full | Interpreting local visual features as a global shape requires awareness |
title_fullStr | Interpreting local visual features as a global shape requires awareness |
title_full_unstemmed | Interpreting local visual features as a global shape requires awareness |
title_short | Interpreting local visual features as a global shape requires awareness |
title_sort | interpreting local visual features as a global shape requires awareness |
topic | Research Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3107621/ https://www.ncbi.nlm.nih.gov/pubmed/21147801 http://dx.doi.org/10.1098/rspb.2010.1909 |
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