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Behavioural Neurology
Volume 24 (2011), Issue 1, Pages 67-74
http://dx.doi.org/10.3233/BEN-2011-0313

The Global Workspace (GW) Theory of Consciousness and Epilepsy

Fabrice Bartolomei1,2,3 and Lionel Naccache4,5,6

1INSERM, U751, Laboratoire de Neurophysiologie et Neuropsychologie, Marseille, F-13005, France
2Université de la Méditerranée, Faculté de Médecine, Marseille, F-13005 France
3CHU Timone, Service de Neurophysiologie Clinique, Assistance Publique des Hôpitaux de Marseille, Marseille, F-13005, France
4AP-HP, Groupe hospitalier Pitié-Salpêtrière, Departments of Neurophysiology & Neurology, Paris, France
5INSERM, ICM Research Center, UMRS 975, Paris, France
6Université Paris 6, Faculté de Médecine Pitié-Salpêtrière, Paris, France

Received 23 March 2011; Accepted 23 March 2011

Copyright © 2011 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The global workspace (GW) theory proposes that conscious processing results from coherent neuronal activity between widely distributed brain regions, with fronto-parietal associative cortices as key elements. In this model, transition between conscious and non conscious states are predicted to be caused by abrupt non-linear massive changes of the level of coherence within this distributed neural space. Epileptic seizures offer a unique model to explore the validity of this central hypothesis. Seizures are often characterized by the occurrence of brutal alterations of consciousness (AOC) which are largely negatively impacting patients' lives. Recently, we have shown that these sudden AOC are contemporary to non-linear increases of neural synchrony within distant cortico-cortical and cortico-thalamic networks. We interpreted these results in the light of GW theory, and suggested that excessive synchrony could prevent this distributed network to reach the minimal level of differentiation and complexity necessary to the coding of conscious representations. These observations both confirm some predictions of the GW model, and further specify the physiological window of neural coherence (minimum and maximum) associated with conscious processing.