Alpha-band suppression in the visual word form area as a functional bottleneck to consciousness.

Détails

ID Serval
serval:BIB_A2743FD0232B
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Alpha-band suppression in the visual word form area as a functional bottleneck to consciousness.
Périodique
Neuroimage
Auteur(s)
Levy J., Vidal J.R., Oostenveld R., FitzPatrick I., Démonet J.F., Fries P.
ISSN
1095-9572 (Electronic)
ISSN-L
1053-8119
Statut éditorial
Publié
Date de publication
2013
Peer-reviewed
Oui
Volume
78
Pages
33-45
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Résumé
The current state of empirical investigations refers to consciousness as an all-or-none phenomenon. However, a recent theoretical account opens up this perspective by proposing a partial level (between nil and full) of conscious perception. In the well-studied case of single-word reading, short-lived exposure can trigger incomplete word-form recognition wherein letters fall short of forming a whole word in one's conscious perception thereby hindering word-meaning access and report. Hence, the processing from incomplete to complete word-form recognition straightforwardly mirrors a transition from partial to full-blown consciousness. We therefore hypothesized that this putative functional bottleneck to consciousness (i.e. the perceptual boundary between partial and full conscious perception) would emerge at a major key hub region for word-form recognition during reading, namely the left occipito-temporal junction. We applied a real-time staircase procedure and titrated subjective reports at the threshold between partial (letters) and full (whole word) conscious perception. This experimental approach allowed us to collect trials with identical physical stimulation, yet reflecting distinct perceptual experience levels. Oscillatory brain activity was monitored with magnetoencephalography and revealed that the transition from partial-to-full word-form perception was accompanied by alpha-band (7-11 Hz) power suppression in the posterior left occipito-temporal cortex. This modulation of rhythmic activity extended anteriorly towards the visual word form area (VWFA), a region whose selectivity for word-forms in perception is highly debated. The current findings provide electrophysiological evidence for a functional bottleneck to consciousness thereby empirically instantiating a recently proposed partial perspective on consciousness. Moreover, the findings provide an entirely new outlook on the functioning of the VWFA as a late bottleneck to full-blown conscious word-form perception.
Mots-clé
Brain/physiology, Brain Mapping, Consciousness/physiology, Female, Humans, Magnetoencephalography, Male, Reading, Visual Perception/physiology, Young Adult
Pubmed
Web of science
Création de la notice
25/06/2013 15:31
Dernière modification de la notice
03/03/2018 20:09
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