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Rohit Marawar, Hsiang J Yeh, Chris Carnabatu, John M Stern
INTRODUCTION: The EEG rhythms demonstrate changes in frequency and power with spontaneous changes in behavioral state that do not have well understood metabolic correlates within the brain. To investigate this question and compare the temporal lobe theta and delta rhythms, resting-state functional MRI (fMRI) was obtained with simultaneous EEG. METHODS: Simultaneous EEG-fMRI was recorded from 14 healthy, sleep-deprived subjects in awake and drowsy states. Scalp electrodes corresponding to bilateral temporal lobes were used to calculate delta and theta band power...
October 18, 2016: Journal of Clinical Neurophysiology: Official Publication of the American Electroencephalographic Society
Johan van der Meer, André Pampel, Eus van Someren, Jennifer Ramautar, Ysbrand van der Werf, German Gomez-Herrero, Jöran Lepsien, Lydia Hellrung, Hermann Hinrichs, Harald Möller, Martin Walter
This data set contains electroencephalography (EEG) data as well as simultaneous EEG with functional magnetic resonance imaging (EEG/fMRI) data. During EEG/fMRI, the EEG cap was outfitted with a hardware-based add-on consisting of carbon-wire loops (CWL). These yielded six extra׳CWL׳ signals related to Faraday induction of these loops in the main magnetic field "Measurement and reduction of motion and ballistocardiogram artefacts from simultaneous EEG and fMRI recordings" (Masterton et al., 2007) [1]. In this data set, the CWL data make it possible to do a direct regression approach to deal with the BCG and specifically He artifact...
June 2016: Data in Brief
Qingbao Yu, Lei Wu, David A Bridwell, Erik B Erhardt, Yuhui Du, Hao He, Jiayu Chen, Peng Liu, Jing Sui, Godfrey Pearlson, Vince D Calhoun
The topological architecture of brain connectivity has been well-characterized by graph theory based analysis. However, previous studies have primarily built brain graphs based on a single modality of brain imaging data. Here we develop a framework to construct multi-modal brain graphs using concurrent EEG-fMRI data which are simultaneously collected during eyes open (EO) and eyes closed (EC) resting states. FMRI data are decomposed into independent components with associated time courses by group independent component analysis (ICA)...
2016: Frontiers in Human Neuroscience
Laura D Lewis, Kawin Setsompop, Bruce R Rosen, Jonathan R Polimeni
Oscillatory neural dynamics play an important role in the coordination of large-scale brain networks. High-level cognitive processes depend on dynamics evolving over hundreds of milliseconds, so measuring neural activity in this frequency range is important for cognitive neuroscience. However, current noninvasive neuroimaging methods are not able to precisely localize oscillatory neural activity above 0.2 Hz. Electroencephalography and magnetoencephalography have limited spatial resolution, whereas fMRI has limited temporal resolution because it measures vascular responses rather than directly recording neural activity...
October 11, 2016: Proceedings of the National Academy of Sciences of the United States of America
Mani Saignavongs, Carolina Ciumas, Mathilde Petton, Romain Bouet, Sébastien Boulogne, Sylvain Rheims, David W Carmichael, Jean-Philippe Lachaux, Philippe Ryvlin
Recent studies have shown that it is feasible to record simultaneously intracerebral EEG (icEEG) and functional magnetic resonance imaging (fMRI) in patients with epilepsy. While it has mainly been used to explore the hemodynamic changes associated with epileptic spikes, this approach could also provide new insight into human cognition. However, the first step is to ensure that cognitive EEG components, that have lower amplitudes than epileptic spikes, can be appropriately detected under fMRI. We compared the high frequency activities (HFA, 50-150[Formula: see text]Hz) elicited by a reading task in icEEG-only and subsequent icEEG-fMRI in the same patients ([Formula: see text]), implanted with depth electrodes...
August 22, 2016: International Journal of Neural Systems
L I Kozlova, M B Shtark, M E Mel'nikov, E G Verevkin, A A Savelov, E D Petrovskii
fMRI-EEG dynamics of brain activity in volunteers was studied during the course of EEG alpha-stimulation training (20 sessions). Twenty-three healthy men (20-35 years) were subjected to 3-fold mapping in a feedback loop (EEG alpha-rhythm biofeedback with acoustic reinforcement). This procedure was performed at the beginning, middle, and end of the course. During the first neurofeedback training session, deactivation (p<0.001) was found in the right angular gyrus, supramarginal, and superior temporal gyri, Brodmann area 39, and cerebellum...
September 2016: Bulletin of Experimental Biology and Medicine
Bernd Feige, Kai Spiegelhalder, Andrea Kiemen, Oliver G Bosch, Ludger Tebartz van Elst, Jürgen Hennig, Erich Seifritz, Dieter Riemann
Functional activation as evidenced by blood oxygen level-dependent (BOLD) functional MRI changes or event-related EEG is known to closely follow patterns of stimulation or self-paced action. Any lags are compatible with axonal conduction velocities and neural integration times. The important analysis of resting state networks is generally based on the assumption that these principles also hold for spontaneous fluctuations in brain activity. Previous observations using simultaneous EEG and fMRI indicate that slower processes, with delays in the seconds range, determine at least part of the relationship between spontaneous EEG and fMRI...
September 13, 2016: NeuroImage
Rolandas Stonkus, Verena Braun, Jess R Kerlin, Gregor Volberg, Simon Hanslmayr
The phase of prestimulus oscillations at 7-10 Hz has been shown to modulate perception of briefly presented visual stimuli. Specifically, a recent combined EEG-fMRI study suggested that a prestimulus oscillation at around 7 Hz represents open and closed windows for perceptual integration by modulating connectivity between lower order occipital and higher order parietal brain regions. We here utilized brief event-related transcranial alternating current stimulation (tACS) to specifically modulate this prestimulus 7 Hz oscillation, and the synchrony between parietal and occipital brain regions...
2016: Scientific Reports
Kees Hermans, Jan de Munck, Rudolf Verdaasdonk, Paul Boon, Gunther Krausz, Robert Prueckl, Pauly Ossenblok
OBJECTIVE: Subtle motion of an epileptic patient examined with co-registered EEG-fMRI may often lead to spurious fMRI activation patterns when true epileptic spikes are contaminated with motion artefacts. In recent years, methods relying on reference signals for correcting these subtle movements in the EEG have emerged. In this study the performance of two reference based devices are compared to the template-based method with regard to their ability to remove movement related artifacts in EEG measured during scanning...
August 25, 2016: IEEE Transactions on Bio-medical Engineering
Elhum A Shamshiri, Tim M Tierney, Maria Centeno, Kelly St Pier, Ronit M Pressler, David J Sharp, Suejen Perani, J Helen Cross, David W Carmichael
Patients with focal epilepsy have been shown to have reduced functional connectivity in intrinsic connectivity networks (ICNs), which has been related to neurocognitive development and outcome. However, the relationship between interictal epileptiform discharges (IEDs) and changes in ICNs remains unclear, with evidence both for and against their influence. EEG-fMRI data was obtained in 27 children with focal epilepsy (mixed localisation and aetiologies) and 17 controls. A natural stimulus task (cartoon blocks verses blocks where the subject was told "please wait") was used to enhance the connectivity within networks corresponding to ICNs while reducing potential confounds of vigilance and motion...
August 20, 2016: Human Brain Mapping
Rodolfo Abreu, Sandro Nunes, Alberto Leal, Patrícia Figueiredo
The study of spontaneous brain activity based on BOLD-fMRI may be seriously compromised by the presence of signal fluctuations of non-neuronal origin, most prominently due to cardiac and respiratory mechanisms. Methods used for modeling and correction of the so-called physiological noise usually rely on the concurrent measurement of cardiac and respiratory signals. In simultaneous EEG-fMRI recordings, which are primarily aimed at the study of spontaneous brain activity, the electrocardiogram (ECG) is typically measured as part of the EEG setup but respiratory data are not generally available...
August 12, 2016: NeuroImage
Siyang Yin, Yuelu Liu, Mingzhou Ding
The mu rhythm is a field oscillation in the ∼10Hz range over the sensorimotor cortex. For decades, the suppression of mu (event-related desynchronization) has been used to index movement planning, execution, and imagery. Recent work reports that non-motor processes, such as spatial attention and movement observation, also desynchronize mu, raising the possibility that the mu rhythm is associated with the activity of multiple brain regions and systems. In this study, we tested this hypothesis by recording simultaneous resting-state EEG-fMRI from healthy subjects...
2016: Frontiers in Human Neuroscience
T Murta, L Hu, T Tierney, U J Chaudhary, M C Walker, D W Carmichael, P Figueiredo, L Lemieux
In current fMRI studies designed to map BOLD changes related to interictal epileptiform discharges (IED), which are recorded on simultaneous EEG, the information contained in the morphology and field extent of the EEG events is exclusively used for their classification. Usually, a BOLD predictor based on IED onset times alone is constructed, effectively treating all events as identical. We used intracranial EEG (icEEG)-fMRI data simultaneously recorded in humans to investigate the effect of including any of the features: amplitude, width (duration), slope of the rising phase, energy (area under the curve), or spatial field extent (number of contacts over which the sharp wave was observed) of the fast wave of the IED (the sharp wave), into the BOLD model, to better understand the neurophysiological origin of sharp wave-related BOLD changes, in the immediate vicinity of the recording contacts...
August 3, 2016: NeuroImage
S Samadi, H Soltanian-Zadeh, C Jutten
Integration of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) is an open problem, which has motivated many researches. The most important challenge in EEG-fMRI integration is the unknown relationship between these two modalities. In this paper, we extract the same features (spatial map of neural activity) from both modality. Therefore, the proposed integration method does not need any assumption about the relationship of EEG and fMRI. We present a source localization method from scalp EEG signal using jointly fMRI analysis results as prior spatial information and source separation for providing temporal courses of sources of interest...
September 2016: Brain Topography
Pierre LeVan, Shuoyue Zhang, Benjamin Knowles, Maxim Zaitsev, Juergen Hennig
OBJECTIVES: In simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI), artifacts on the EEG arise from the switching of magnetic field gradients in the MR scanner. These artifacts depend on head position, and are therefore difficult to remove in the presence of subject motion. In this work, gradient artifacts are modelled by multiple templates extracted from externally recorded motion information. METHODS: Gradient artifact correction was performed in EEG-fMRI recordings by estimating artifactual templates modulated by slowly varying splines, as well as head position information...
July 21, 2016: IEEE Transactions on Bio-medical Engineering
Daesung Kang, Yuelu Liu, Vladimir Miskovic, Andreas Keil, Mingzhou Ding
It has been hypothesized that the medial prefrontal cortex (mPFC) is a hub in the network that mediates appetitive responses whereas the amygdala is thought to mediate both aversive and appetitive processing. Both structures may facilitate adaptive responses to emotional challenge by linking perception, attention, memory, and motor circuits. We provide an initial exploration of these hypotheses by recording simultaneous EEG-fMRI in eleven participants viewing affective pictures. MPFC- and amygdala-seeded functional connectivity maps were generated by applying the beta-series correlation method...
November 2016: Psychophysiology
José L Ferreira, Yan Wu, René M H Besseling, Rolf Lamerichs, Ronald M Aarts
Over the past years, coregistered EEG-fMRI has emerged as a powerful tool for neurocognitive research and correlated studies, mainly because of the possibility of integrating the high temporal resolution of the EEG with the high spatial resolution of fMRI. However, additional work remains to be done in order to improve the quality of the EEG signal recorded simultaneously with fMRI data, in particular regarding the occurrence of the gradient artefact. We devised and presented in this paper a novel approach for gradient artefact correction based upon optimised moving-average filtering (OMA)...
2016: Journal of Medical Engineering
R Marecek, M Lamos, M Mikl, M Barton, J Fajkus, Rektor, M Brazdil
OBJECTIVE: The scalp EEG spectrum is a frequently used marker of neural activity. Commonly, the preprocessing of EEG utilizes constraints, e.g. dealing with a predefined subset of electrodes or a predefined frequency band of interest. Such treatment of the EEG spectrum neglects the fact that particular neural processes may be reflected in several frequency bands and/or several electrodes concurrently, and can overlook the complexity of the structure of the EEG spectrum. APPROACH: We showed that the EEG spectrum structure can be described by parallel factor analysis (PARAFAC), a method which blindly uncovers the spatial-temporal-spectral patterns of EEG...
August 2016: Journal of Neural Engineering
Katharina Körbl, Julia Jacobs, Michael Herbst, Maxim Zaitsev, Andreas Schulze-Bonhage, Jürgen Hennig, Pierre LeVan
OBJECTIVES: Ballistocardiographic (BCG) artifacts resemble interictal epileptic discharges (IEDs) and can lead to incorrect IED identification in EEG-fMRI. This study investigates IEDs marked in EEGs corrected using information from a moiré phase tracking (MPT) marker. METHODS: EEG-fMRI from 18 patients was processed with conventional methods for BCG removal, while 9 patients used a MPT marker. IEDs were marked first without ECG information. In a second review, suspicious IEDs synchronous with the BCG were discarded...
August 2016: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
Sreenath Kyathanahally, Ana Franco-Watkins, Xiaoxia Zhang, Vince Calhoun, Gopikrishna Deshpande
Human decision-making is a multidimensional construct, driven by a complex interplay between external factors, internal biases and computational capacity constraints. Here we propose a layered approach to experimental design in which multiple tasks - from simple to complex - with additional layers of complexity introduced at each stage, are incorporated for investigating decision-making. This is demonstrated using tasks involving intertemporal choice between immediate and future prospects. Previous functional magnetic resonance imaging (fMRI) and electroencephalographic (EEG) studies have separately investigated the spatial and temporal neural substrates, respectively, of specific factors underlying decision making...
July 12, 2016: IEEE Journal of Biomedical and Health Informatics
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