Visual crowding in V1.
| Autor: | Millin R; Neuroscience Graduate Program., Arman AC; Neuroscience Graduate Program, Current address: Deallus Group, Los Angeles, CA 90025, USA., Chung ST; School of Optometry, University of California, Berkeley, CA 94720-2020, USA and., Tjan BS; Neuroscience Graduate Program, Department of Psychology, University of Southern California, Los Angeles, CA 90089-1061, USA. |
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| Jazyk: | angličtina |
| Zdroj: | Cerebral cortex (New York, N.Y. : 1991) [Cereb Cortex] 2014 Dec; Vol. 24 (12), pp. 3107-15. Date of Electronic Publication: 2013 Jul 05. |
| DOI: | 10.1093/cercor/bht159 |
| Abstrakt: | In peripheral vision, objects in clutter are difficult to identify. The exact cause of this "crowding" effect is unclear. To perceive coherent shapes in clutter, the visual system must integrate certain local features across receptive fields while preventing others from being combined. It is believed that this selective feature integration-segmentation process is impaired in peripheral vision, leading to crowding. We used functional magnetic resonance imaging (fMRI) to investigate the neural origin of crowding. We found that crowding was associated with suppressed fMRI signal as early as V1, regardless of whether attention was directed toward or away from a target stimulus. This suppression in early visual cortex was greatest for stimuli that produced the strongest crowding. In contrast, the pattern of activity was mixed in higher level visual areas, such as the lateral occipital cortex. These results support the view that the deficiency in feature integration and segmentation in peripheral vision is present at the earliest stages of cortical processing. (© The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.) |
| Databáze: | MEDLINE |
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