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Brain dynamics underlying the nonlinear threshold for access to consciousness.

Authors :
Antoine Del Cul
Sylvain Baillet
Stanislas Dehaene
Source :
PLoS Biology, Vol 5, Iss 10, p e260 (2007)
Publication Year :
2007
Publisher :
Public Library of Science (PLoS), 2007.

Abstract

When a flashed stimulus is followed by a backward mask, subjects fail to perceive it unless the target-mask interval exceeds a threshold duration of about 50 ms. Models of conscious access postulate that this threshold is associated with the time needed to establish sustained activity in recurrent cortical loops, but the brain areas involved and their timing remain debated. We used high-density recordings of event-related potentials (ERPs) and cortical source reconstruction to assess the time course of human brain activity evoked by masked stimuli and to determine neural events during which brain activity correlates with conscious reports. Target-mask stimulus onset asynchrony (SOA) was varied in small steps, allowing us to ask which ERP events show the characteristic nonlinear dependence with SOA seen in subjective and objective reports. The results separate distinct stages in mask-target interactions, indicating that a considerable amount of subliminal processing can occur early on in the occipito-temporal pathway (270 ms) and highly distributed fronto-parieto-temporal activation as a correlate of conscious reportability.

Subjects

Subjects :
Biology (General)
QH301-705.5

Details

Language :
English
ISSN :
15449173 and 15457885
Volume :
5
Issue :
10
Database :
Directory of Open Access Journals
Journal :
PLoS Biology
Publication Type :
Academic Journal
Accession number :
edsdoj.7105ad8f49f34e1397801d03b28ae91f
Document Type :
article
Full Text :
https://doi.org/10.1371/journal.pbio.0050260