Neuroscience of Consciousness
July 12, 2024
P. Pérez, D. Manasova, B. Hermann et al.
A framework is introduced that characterizes neuronal markers of consciousness along two dimensions: how well they distinguish conscious from non-conscious states (x-axis) and how well they distinguish different conscious contents (y-axis). Using electroencephalography markers of connectivity, complexity, and spectral summaries, the framework is applied to healthy participants during a nap and patients with disorders of consciousness for the state dimension, and to healthy participants in visual awareness and auditory local-global paradigms for the content dimension. Separate clusters of markers with correlated and anticorrelated dynamics emerge, highlighting the complex relationship between the state and content of consciousness and the need to consider them together.
Dialogues in Clinical Neuroscience
May 20, 2024
L. Naccache, E. Munoz-Musat
A general model of Functional Neurological Disorders (FND) proposes that these disorders may arise from a consciously initiated voluntary top-down process that produces involuntary lasting consequences, which the patient then consciously experiences and interprets as involuntary. The model is developed within the Global Neuronal Workspace theory of consciousness, which describes interactions between conscious and non-conscious cognitive processes. A list of predictions for empirical testing is presented, and the model reinterprets the debated links between hypnotic suggestion and FND. The theoretical paper aims to bridge psychiatric and neurological perspectives on FND with advances in cognitive neuroscience of consciousness.
Neuroscience of Consciousness
December 1, 2021
B. Hermann, A. Sangaré, E. Munoz-Musat et al.
Patients with disorders of consciousness (DoC), such as vegetative state (VS) or minimally conscious state (MCS), offer a unique way to test theories about consciousness by dissociating vigilance from conscious experience. This article reviews major findings in DoC research, proposes a taxonomy, and highlights limitations. A purely behavioral approach is insufficient to assess conscious state. Comparing MCS and VS does not provide a clean contrast between conscious and unconscious states. Based on resting-state PET data, behavioral MCS reflects a cortically mediated state that does not necessarily imply preserved consciousness.
Nature Human Behaviour
February 1, 2019
M. Michel, Diane M Beck, N. Block et al.
Advancing scientific research on consciousness is important for addressing clinical and ethical issues in neurology and mental health. To support this field, funding priorities must be set carefully, and challenges such as job creation and media misrepresentation need to be addressed.
Behavioural Neurology
March 29, 2011
F. Bartolomei, L. Naccache
Conscious processing arises from coherent neuronal activity across widely distributed brain regions, particularly fronto-parietal associative cortices, according to global workspace theory. Transitions between conscious and non-conscious states involve abrupt, non-linear changes in neural coherence. Epileptic seizures, which often cause brutal alterations of consciousness, provide a test of this hypothesis. Recent findings show that sudden loss of consciousness during seizures coincides with non-linear increases in neural synchrony within distant cortico-cortical and cortico-thalamic networks. Excessive synchrony may prevent the distributed network from achieving the differentiation and complexity needed for conscious representation. These observations confirm predictions of the global workspace model and define a physiological window of neural coherence associated with conscious processing.