Measures of metabolism and complexity in the brain of patients with disorders of consciousness

Authors: Bodart O; Gosseries O; Wannez S; Thibaut A; Annen J; Boly M; Rossanova M; Casali A; Casarotto S; Tononi G; Massimini M; Laureys S Background Making an accurate diagnosis in patients with disorders of consciousness remains challenging. 18F-fluorodeoxyglucose (FDG)–PET has been validated as a diagnostic tool in this population, and allows identifying unresponsive patients with a capacity for consciousness. In parallel, the perturbational complexity index (PCI), a […]

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Tracking dynamic interactions between structural and functional connectivity: a TMS/EEG-dMRI study

Authors:Amico E; Bodart O; Rosanova M; Gosseries O; Heine L; Van Mierlo P; Martial C; Massimini M; Marianazzo D; Laureys S Transcranial magnetic stimulation (TMS) in combination with neuroimaging techniques allows to measure the effects of a direct perturbation of the brain. When coupled with high-density electroencephalography (TMS/hd-EEG), TMS pulses revealed electrophysiological signatures of different cortical modules in health and disease. However, the neural […]

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Neural correlates of consciousness: progress and problems

Authors: Koch C; Massimini M; Boly M; Tononi G There have been a number of advances in the search for the neural correlates of consciousness — the minimum neural mechanisms sufficient for any one specific conscious percept. In this Review, we describe recent findings showing that the anatomical neural correlates of consciousness are primarily localized to a posterior cortical […]

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Modulation of Total Sleep Time by Transcranial Direct Current Stimulation (tDCS)

Authors: Frase L; Piosczyk H; Zittel S; Jahn F; Selhausen P; Krone L; Feige B; Mainberger F; Maier J M; Kuhn M; Kloppel S; Normann C; Sterr A; Spiegelhalder K; Riemann D; Nitsche M; Nissen C Arousal and sleep are fundamental physiological processes, and their modulation is of high clinical significance. This study tested the hypothesis that total sleep time (TST) in humans can be modulated by the non-invasive brain stimulation technique transcranial […]

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Brain–computer interfaces for communication and rehabilitation

Authors: Chaudhary U; Birbaumer N; Ramos-Murguialday A Brain–computer interfaces (BCIs) use brain activity to control external devices, thereby enabling severely disabled patients to interact with the environment. A variety of invasive and noninvasive techniques for controlling BCIs have been explored, most notably EEG, and more recently, near-infrared spectroscopy. Assistive BCIs are designed to enable paralyzed patients to communicate […]

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Stratification of unresponsive patients by an independently validated index of brain complexity.

Authors: Casarotto S; Comanducci A; Rosanova M; Sarasso S; Fecchio M; Napolitani M; Pigorini A; G Casali A; Trimarchi PD; Boly M; Gosseries O; Bodart O; Curto F; Landi C; Mariotti M; Devalle G; Laureys S; Tononi G; Massimini M OBJECTIVE: Validating objective, brain-based indices of consciousness in behaviorally unresponsive patients represents a challenge due to the impossibility of obtaining independent evidence through subjective reports. Here we address this problem by first validating a […]

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Brain–Computer Interface–Based Communication in the Completely Locked-In State

Authors: Chaudhary U; Xia B; Silvoni S; Cohen L.G; Birbaumer N Despite partial success, communication has remained impossible for persons suffering from complete motor paralysis but intact cognitive and emotional processing, a state called com- plete locked-in state (CLIS). Based on a motor learning theoretical context and on the failure of neuroelectric brain–computer interface (BCI) communication attempts in CLIS, we […]

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Consciousness and cortical responsiveness: a within-state study during non-rapid eye movement sleep

Authors: Nieminen J; Gosseries O; Massimini M; Saad E; Sheldon A.D.; Boly M; Siclari F; Postle B; Tononi G When subjects become unconscious, there is a characteristic change in the way the cerebral cortex responds to perturbations, as can be assessed using transcranial magnetic stimulation and electroencephalography (TMS–EEG). For instance, compared to wakefulness, during non-rapid eye movement (NREM) sleep TMS elicits a larger positive–negative […]

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Closed-loop brain training: the science of neurofeedback

Authors: Sitaram R; Ros T; Stoeckel L; Haller S; Scharnowski F; Lewis-Peacock J; Weiskopf N; Belfari M.L.; Rana M; Oblak E; Birbaumer N; Sulzer J Neurofeedback is a psychophysiological procedure in which online feedback of neural activation is provided to the participant for the purpose of self-regulation. Learning control over specific neural substrates has been shown to change specific behaviours. As a progenitor of brain–machine interfaces, neurofeedback […]

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Optimization of multifocal transcranial current stimulation for weighted cortical pattern targeting from realistic modeling of electric fields.

Authors: Ruffini G, Fox MD, Ripolles O, Miranda PC, Pascual-Leone A. — Recently, multifocal transcranial current stimulation (tCS) devices using several relatively small electrodes have been used to achieve more focal stimulation of specific cortical targets. However, it is becoming increasingly recognized that many behavioral manifestations of neurological and psychiatric disease are not solely the result […]

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