title: Spontaneous Fluctuations and Non-linear Ignitions: Two Dynamic Faces of Cortical Recurrent Loops.
abstract: Recent human neurophysiological recordings have uncovered two fundamental modes of cerebral cortex activity with distinct dynamics: an active mode characterized by a rapid and sustained activity ("ignition") and a spontaneous (resting-state) mode, manifesting ultra-slow fluctuations of low amplitude. We propose that both dynamics reflect two faces of the same recurrent loop mechanism: an integration device that accumulates ongoing stochastic activity and, either spontaneously or in a task-driven manner, crosses a dynamic threshold and ignites, leading to content-specific awareness. The hypothesis can explain a rich set of behavioral and neuronal phenomena, such as perceptual threshold, the high non-linearity of visual responses, the subliminal nature of spontaneous activity fluctuations, and the slow activity buildup anticipating spontaneous behavior (e.g., readiness potential). Further elaborations of this unified scheme, such as a cascade of integrators with different ignition thresholds or multi-stable states, can account for additional complexities in the repertoire of human cortical dynamics.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, U992, Cognitive Neuroimaging Unit, NeuroSpin Center, Saclay Center, 91191 Gif-sur-Yvette, France; Commissariat à l'Energie Atomique, Division of Life Sciences, Institute of BioImaging, NeuroSpin Center, 91191 Gif-sur-Yvette, France; Université Paris-Sud, Cognitive Neuroimaging Unit, 91405 Orsay Cedex, France.
authors.forename: Clément
authors.initials: C
authors.lastname: Moutard
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, U992, Cognitive Neuroimaging Unit, NeuroSpin Center, Saclay Center, 91191 Gif-sur-Yvette, France; Commissariat à l'Energie Atomique, Division of Life Sciences, Institute of BioImaging, NeuroSpin Center, 91191 Gif-sur-Yvette, France; Université Paris-Sud, Cognitive Neuroimaging Unit, 91405 Orsay Cedex, France; Collège de France, Place Marcelin Berthelot, 75005 Paris, France.
authors.forename: Stanislas
authors.initials: S
authors.lastname: Dehaene
authors.affiliation: Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel. Electronic address: rafi.malach@gmail.com.
authors.forename: Rafael
authors.initials: R
authors.lastname: Malach
mesh_terms: D001364:Awareness / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology*; D004569:Electroencephalography; D006801:Humans; D009474:Neurons / Q000502:physiology*; D017711:Nonlinear Dynamics; D012684:Sensory Thresholds / Q000502:physiology*