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Title

Temporal dynamics of awareness for facial identity revealed with ERP

Authors
Heinzer, Severine
Published in Brain and Cognition. 2009, vol. 69, no. 2, p. 296-305
Abstract In this study, we investigated the scalp recorded event-related potential (ERP) responses related to visual awareness. A backward masking procedure was performed while high-density EEG recordings were carried out. Subjects were asked to detect a familiar face, presented at durations that varied parametrically between 16 and 266 ms. ERPs were computed and awareness was assessed using a sensitivity measure from signal detection theory (d'). Modifications in the electrical scalp topographies were found to reflect visual awareness of the stimulus. In particular, an early map topography was found to emerge progressively around 230 ms, showing a pattern of increase similar to the measure of visual awareness. This was followed by an increase in duration of a second, P300-like map. Source localisation for the early awareness-related topography revealed the activation of a distributed network of brain areas including frontal and temporo-occipital regions. Our results suggest that conscious experience emerges in parallel with the activation of a specific neural network that occurs in a time window beginning from about 200 ms.
Keywords AdultAnalysis of VarianceBrain/physiologyElectroencephalographyEvoked Potentials, VisualFaceFemaleHumansMalePattern Recognition, Visual/physiologyTask Performance and AnalysisVisual Perception/physiologyYoung Adult
Stable URL http://archive-ouverte.unige.ch/unige:1436
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Identifiers
PMID: 18818007
Structures
Research groups Organisation et plasticité des réseaux neuronaux cérébraux (148)
Neuropsychologie clinique appliquée et neurosciences cognitives (703)

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Deposited on : 2009-04-28

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