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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From Oscillatory Transcranial Current Stimulation to Scalp EEG Changes: A Biophysical and Physiological Modeling Study

 Authors: Isabelle Merlet , Gwénaël Birot, Ricardo Salvador, Behnam Molaee-Ardekani, Abeye Mekonnen, Aureli Soria-Frish, Giulio Ruffini, Pedro C. Miranda, Fabrice Wendling. — Both biophysical and neurophysiological aspects need to be considered to assess the impact of electric fields induced by transcranial current stimulation (tCS) on the cerebral cortex and the subsequent effects occurring on scalp EEG. The objective of this work was to elaborate a […]

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Sensitivity to auditory spectral width in the fetus and infant – an fMEG study

Authors: Jana Muenssinger, Tamara Matuz, Franziska Schleger, Rossitza Draganova, Magdalene Weiss, Isabelle Kiefer-Schmidt, Annette Wacker-Gussmann, Rathinaswamy B. Govindan, Curtis L. Lowery, Hari Eswaran and Hubert Preissl — Auditory change detection is crucial for the development of the auditory system and a prerequisite for language development. In neonates, stimuli with broad spectral width like white noise (WN) elicit the […]

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Communication in locked-in state after brainstem stroke: a brain-computer-interface approach

Authors: Ujwal Chaudhary and Niels Birbaumer — In a recent study by Sellers et al. (1) a patient in locked-in state after brainstem stroke was able to successfully communicate via electroencephalography (EEG) based brain computer interface (BCI) employing a P300 speller paradigm. BCI uses the brain signal, which can either be the electrical signal (electroencephalography-EEG) (2) or a […]

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Using transcranial direct current stimulation to improve consciousness of severly brain injured patients- a sham-controlled double blind study

Authors: Aurore Thibaut , Marie-Aurélie Bruno, Didier Ledoux, Athena Demertzi and Steven Laureys — Objectives: Previous studies showed that anodal transcranial direct current stimulation (tDCS) applied to the left dorsolateral prefrontal (DLPF) affected hemisphere after stroke transiently improves performance of memory (1) and attention (2). In this study, we tested the effect of tDCS on the level of consciousness in […]

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Induction of self awareness in dreams through frontal low current stimulation of gamma activity

Authors: Ursula Voss, Romain Holzmann, Allan Hobson, Walter Paulus, Judith Koppehele-Gossel, Ansgar Klimke Michael A Nitsche — Recent findings link fronto-temporal gamma electroencephalographic (EEG) activity to conscious awareness in dreams, but a causal relationship has not yet been established. We found that current stimulation in the lower gamma band during REM sleep influences ongoing brain activity and induces self-reflective awareness in dreams. Other […]

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Slow-Wave Activity Saturation and Thalamocortical Isolation During Propofol Anesthesia in Humans

Authors: Róisín Ní Mhuircheartaigh, Catherine Warnaby, Richard Rogers, Saad Jbabdi and Irene Tracey — The altered state of consciousness produced by general anesthetics is associated with a variety of changes in the brain’s electrical activity. Under hyperpolarizing influences such as anesthetic drugs, cortical neurons oscillate at ~1 Hz, which is measurable as slow waves in the […]

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A Theoretically Based Index of Consciousness Independent of Sensory Processing and Behavior

Authors: Adenauer G. Casali, Olivia Gosseries, Mario Rosanova, Mélanie Boly, Simone Sarasso1, Karina R. Casali, Silvia Casarotto, Marie-Aurélie Bruno, Steven Laureys, Giulio Tononi and Marcello Massimini — One challenging aspect of the clinical assessment of brain-injured, unresponsive patients is the lack of an objective measure of consciousness that is independent of the subject’s ability to interact […]

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