Boundary completion is automatic and dissociable from shape discrimination

Détails

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Etat: Serval
Version: Final published version
ID Serval
serval:BIB_73DC4CD35F69
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Boundary completion is automatic and dissociable from shape discrimination
Périodique
Journal of Neuroscience
Auteur(s)
Murray  M. M., Imber  M. L., Javitt  D. C., Foxe  J. J.
ISSN
1529-2401
Statut éditorial
Publié
Date de publication
11/2006
Peer-reviewed
Oui
Volume
26
Numéro
46
Pages
12043-54
Notes
Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't --- Old month value: Nov 15
Résumé
Normal visual perception readily overcomes suboptimal or degraded viewing conditions through perceptual filling-in processes, enhancing object recognition and discrimination abilities. This study used visual evoked potential (VEP) recordings in conjunction with electrical neuroimaging analyses to determine the spatiotemporal brain dynamics of boundary completion and shape discrimination processes in healthy humans performing the so-called "thin/fat" discrimination task (Ringach and Shapley, 1996) with stimuli producing illusory contours. First, results suggest that boundary completion processes occur independent of subjects' accuracy on the discrimination task. Modulation of the VEP to the presence versus absence of illusory contours [the IC effect (Murray et al., 2002)] was indistinguishable in terms of response magnitude and scalp topography over the 124-186 ms poststimulus period, regardless of whether task performance was correct. This suggests that failure on this discrimination task is not primarily a consequence of failed boundary completion. Second, the electrophysiological correlates of thin/fat shape discrimination processes are temporally dissociable from those of boundary completion, occurring during a substantially later phase of processing (approximately 330-406 ms). The earlier IC effect was unaffected by whether the perceived contour produced a thin or fat shape. In contrast, later time periods of the VEP modulated according to perceived shape only in the case of stimuli producing illusory contours, but not for control stimuli for which performance was at near-chance levels. Collectively, these data provide further support for a multistage model of object processing under degraded viewing conditions.
Mots-clé
Adult Brain Mapping/methods Contrast Sensitivity/*physiology Electroencephalography/methods Evoked Potentials/physiology Evoked Potentials, Visual/*physiology Female Functional Laterality/physiology Humans Male Pattern Recognition, Visual/*physiology Perceptual Closure/*physiology Photic Stimulation Reaction Time/physiology Visual Cortex/*physiology Visual Pathways/*physiology
Pubmed
Web of science
Open Access
Oui
Création de la notice
21/01/2008 11:23
Dernière modification de la notice
08/05/2019 20:26
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