Research Topics
Species | Nelson J Trujillo-BarretoSummaryAffiliation: Cuban Neuroscience Centre Location: Havana, Cuba Summary: Since I graduated from Nuclear Physics at the Higher Institute for Nuclear Science and Technology in 1995 I joined the Neuroinformatics Department at the Cuban Neuroscience Centre, where Im currently a Senior researcher and the leader of the Brain Dynamics Group. My research activities have focused on the development of statistical estimation methods as well as probabilistic and biophysical models for the analysis of different types of human brain activity measurements and their integration. This entails bridging the gap between data produced by recording machines and the actual underlying neuronal activity by solving the forward (from neuronal activity to data) and inverse problems (from data to neuronal activity) that arise in each case. This goal has been played out to different extents in a variety of functional techniques like Electro and Magneto encephalography (EEG/MEG), functional Magnetic Resonance Imaging, Diffusion Tensor Imaging (DTI) and others. Particularly I have intensively worked in the development of the so called Brain Electromagnetic Tomography (BET). This allows reconstructing 3D images of electric activity inside the brain from EEG/MEG measurements with a very high temporal resolution. BET can also benefit from the high spatial resolution of fMRI as well as the detailed anatomical connectivity information from DTI, in order to obtain more accurate spatio-temporal brain source imaging of a wide variety of cognitive functions. For this, I have focused in the development of models that allow describing the relationship between this variety of data and their coupling with the common underlying neuronal activity. Along years, through collaborative efforts with different laboratories (Functional Imaging Laboratory at UCL, School of Psychological Sciences (University of Manchester), School of Computing & Mathematical Sciences (John Moores University), Institut für Allgemeine Psychologie (University of Leipzig), Max Planck Institute for Biological Cybernetics) I have also become involved in the application of BET to the localization of sources generating human ERPs in a variety of Neuropsychological contexts including: expectation and processing of pain, recognition and processing of faces, rapid extraction of auditory feature contingencies, localization of verbal and non-verbal N400 component, sustained spatial attention to vibration, processing of abstract rule violations in audition, use of P300 component in the diagnosis of cerebrovascular disease, enhancement of colour signals during feature-selective attention, mechanisms for detecting auditory temporal and spectral deviations, early correlates of visual awareness following orientation and colour rivalry, localization and long range synchrony of induced Gamma band responses during object recognition tasks, repetition suppression of induced Gamma band responses. I am a reviewer for NeuroImagel, Human Brain Mapping, IEEE Transactions on Medical Imaging, Neural Networks, Biometrics, PLoS in Computational Biology, PLoS Biology, PLoS One, Frontiers in Human Neuroscience, EURASIP Journal of Advanced Signal Processing, Journal of Integrative Neuroscience, Cellular and Molecular Biology, Psychophysiology, Clinical EEG and Neuroscience, Medical & Biological Engineering & Computing and Physica Scripta. I am also Member of the Editorial Board of the journal Computational and Mathematical Methods in Medicine. Publications
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Detail Information
Publications
Biophysical model for integrating neuronal activity, EEG, fMRI and metabolismRoberto C Sotero
Brain Dynamics Department, Cuban Neuroscience Center, Avenue 25, Esq 158, 15202, PO Box 6412, 6414, Cubanacan, Playa, Havana, Cuba
Neuroimage 39:290-309. 2008..The origin of negative BOLD responses and the characteristics of EEG, PET and BOLD signals in Alzheimer's disease were also studied...
Processing of abstract rule violations in auditionErich Schroger
Institute of Psychology I, University of Leipzig, Leipzig, Germany
PLoS ONE 2:e1131. 2007..Our study provides the first evidence for the task-independence (i.e. automaticity) of this ability to encode abstract rules and for its immediate consequences for subsequent mental processes...- Multiple sparse priors for the M/EEG inverse problemKarl Friston
The Wellcome Trust Centre for Neuroimaging, Institute of Neurology, UCL, 12 Queen Square, London, WC1N 3BG, UK
Neuroimage 39:1104-20. 2008..This means the approach automatically selects either a sparse or a distributed model, depending on the data. The scheme is compared with conventional applications of Bayesian solutions to quantify the improvement in performance... 
Sources of synchronized induced Gamma-Band responses during a simple object recognition task: a replication study in human MEGT Gruber
Institute for Psychology I, University of Leipzig, Leipzig, Germany
Brain Res 1196:74-84. 2008..g. reference confounds). In contrast to the iGBR, the localization of event-related fields (ERFs) and evoked Gamma-Band Response (eGBRs) revealed generators in focal visual areas, and thus, seem to mirror early sensory processing...- Diffusion-based spatial priors for functional magnetic resonance imagesL M Harrison
Wellcome Trust Centre for Neuroimaging, UCL, London, UK
Neuroimage 41:408-23. 2008..Indeed, for the auditory data we provide strong evidence for a non-stationary process, which concurs with a qualitative comparison of predicted activations at the boundary of functionally selective regions... - DEM: a variational treatment of dynamic systemsK J Friston
The Wellcome Department of Imaging Neuroscience, University College London, United Kingdom
Neuroimage 41:849-85. 2008..Furthermore, it provides for dual and triple inferences on a system's states, parameters and hyperparameters using exactly the same principles. We refer to this approach as dynamic expectation maximisation (DEM)... - Rapid extraction of auditory feature contingenciesAlexandra Bendixen
Institute for Psychology I, University of Leipzig, Germany
Neuroimage 41:1111-9. 2008..This capacity is of fundamental importance for the organism in its attempt to model the sensory environment outside the focus of attention... - Early correlates of visual awareness in the human brain: Time and place from event-related brain potentialsUrte Roeber
Institute for Psychology I, University of Leipzig, Leipzig, Germany
J Vis 8:21.1-12. 2008..We place the earliest correlate of visual awareness following binocular rivalry in the ventrolateral occipitotemporal cortex... - Early correlates of visual awareness following orientation and colour rivalrySandra Veser
Institute of Psychology I, Leipzig University, Seeburgstr 14 20, 04103 Leipzig, Germany
Vision Res 48:2359-69. 2008..We conclude that the rivalling stimulus property influences the timing of modulation of correlates of visual awareness in a property-independent cortical network... - Identification and comparison of stochastic metabolic/hemodynamic models (sMHM) for the generation of the BOLD signalRoberto C Sotero
Brain Dynamics Department, Cuban Neuroscience Center, Avenue 25, Esq 158, 15202, Cubanacan, Playa, P O Box 6412, Havana, Cuba
J Comput Neurosci 26:251-69. 2009..Data was best described by model II, although model III was also supported... - BET differences among simultaneous evoked frequency band responses during early-stage visual processing distinguish schizophrenia from healthy subjectsJ A Gonzalez-Hernandez
Hermanos Ameijeiras Hospital, Havana, Cuba University Hospital of Düsseldorf, Dusseldorf, Germany
Neurosci Lett 450:7-11. 2009..We concluded that this result provides important evidence indicating that the proposed method is able to differentiate electrophysiological patterns in healthy subjects from those in patients with schizophrenia... - Random fields--union intersection tests for detecting functional connectivity in EEG/MEG imagingFelix Carbonell
Department of Mathematics and Statistics, McGill University, Montreal, Canada
Hum Brain Mapp 30:2477-86. 2009..The performance of the proposed method is illustrated with real ERP data obtained from a face recognition experiment... - ERP generator anomalies in presymptomatic carriers of the Alzheimer's disease E280A PS-1 mutationMaria A Bobes
Cognitive Neuroscience Department, Cuban Center for Neuroscience, Havana, Cuba
Hum Brain Mapp 31:247-65. 2010.... - Bayesian M/EEG source reconstruction with spatio-temporal priorsNelson J Trujillo-Barreto
Brain Dynamics Department, Cuban Neuroscience Centre, P O Box 6412 6414, Ave 25, Esq 158, No 15202, Cubanacan, Playa, Havana, Cuba
Neuroimage 39:318-35. 2008..Finally, the VB-GLM approach is used to analyze an EEG data set from a face processing experiment... - Diffusion-based spatial priors for imagingL M Harrison
The Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, 12 Queen Square, London, WC1N 3BG, UK
Neuroimage 38:677-95. 2007..Critically, this means adaptive smoothing becomes an integral part of estimation and inference. We illustrate the method using synthetic and real fMRI data... - 3D statistical parametric mapping of EEG source spectra by means of variable resolution electromagnetic tomography (VARETA)J Bosch-Bayard
Laboratory of Neurosciences, Cuban National Scientific Research Center, Havana, Cuba
Clin Electroencephalogr 32:47-61. 2001..The statistical issues involved are addressed by the use of extreme value statistics. Examples are shown that illustrate the potential clinical utility of the methods herein developed... - [Cognitive diagnosis of cerebrovascular disease by event related potentials: anatomical sources that generate P300]E Alonso-Prieto
Departamento de Neuropsicología, Instituto Nacional de Neurologia y Neurocirugia, La Habana, Cuba
Rev Neurol 38:229-33. 2004..There is a need to develop tools that are capable of diagnosing them. One of them could be event related potentials. These provide an indicator of cognitive processing in real time... - Bayesian model averaging in EEG/MEG imagingNelson J Trujillo-Barreto
Cuban Neuroscience Center, Havana, Cuba
Neuroimage 21:1300-19. 2004.... - Bayesian fMRI time series analysis with spatial priorsWilliam D Penny
Wellcome Department of Imaging Neuroscience, UCL, London, UK
Neuroimage 24:350-62. 2005..Our model generalizes earlier work on voxel-wise estimation of GLM-AR models and inference in GLMs using Posterior Probability Maps (PPMs). Results are shown on simulated data and on data from an event-related fMRI experiment... - Brain electrical tomography (BET) analysis of induced gamma band responses during a simple object recognition taskThomas Gruber
Universitat Leipzig, Institut fur Psychologie I, Seeburgstrasse 14 20, 04103 Leipzig, Germany
Neuroimage 29:888-900. 2006.... - Mechanisms for detecting auditory temporal and spectral deviations operate over similar time windows but are divided differently between the two hemispheresSabine Grimm
Kognitive einschl Biologische Psychologie, Institut fur Psychologie I, Universitat Leipzig, Seeburgstrasse 14 20, 04103 Leipzig, Germany
Neuroimage 32:275-82. 2006..Importantly, the decline of MMN to unattended sounds with larger temporal distance suggests that parts beyond 300 ms are less important for preattentive auditory object representation... - Variational free energy and the Laplace approximationKarl Friston
The Wellcome Department of Imaging Neuroscience, Institute of Neurology, UCL, 12 Queen Square, London, WC1N 3BG, UK
Neuroimage 34:220-34. 2007..Finally, we also consider, briefly, dynamic models and how these inform the regularisation of free energy ascent schemes, like EM and ReML... - Repetition suppression of induced gamma band responses is eliminated by task switchingThomas Gruber
Universitat Leipzig, Institut fur Psychologie I, Seeburgstrasse 14 20, 04103 Leipzig, Germany
Eur J Neurosci 24:2654-60. 2006..The ERP (220-380 ms) revealed suppression effects independent of task demands in bilateral posterior areas and might indicate correlates of repetition priming in perceptual structures... - Bayesian comparison of spatially regularised general linear modelsWill Penny
Wellcome Department of Imaging Neuroscience, University College, London WC1N 3BG, UK
Hum Brain Mapp 28:275-93. 2007..We also provide extensions that implement spatial and anatomical regularisation of noise process parameters... - Sustained spatial attention to vibration is mediated in primary somatosensory cortexC M Giabbiconi
Institut fur Psychologie I, Universitat Leipzig, Seeburgstrasse 14 20, D 04103 Leipzig, Germany
Neuroimage 35:255-62. 2007..These result patterns were seen as evidence for a low-level sensory gain control mechanism in tactile spatial attention... - Realistically coupled neural mass models can generate EEG rhythmsRoberto C Sotero
Cuban Neuroscience Center, Brain Dynamics Department, Havana, Cuba
Neural Comput 19:478-512. 2007..Simulations of human brain rhythms were carried out in order to test the model. Physiologically plausible results were obtained based on this anatomically constrained neural mass model... - Modelling the role of excitatory and inhibitory neuronal activity in the generation of the BOLD signalRoberto C Sotero
Cuban Neuroscience Center, Ave 25, Esq 158, No 15202, Cubanacan, Playa, Ciudad Habana, P O Box 6412 6414, Cuba
Neuroimage 35:149-65. 2007..Interestingly, NBS was associated with negative oxygen consumption changes only for the case of mechanism (ii)... - Directed cortical information flow during human object recognition: analyzing induced EEG gamma-band responses in brain's source spaceGernot G Supp
Department of Neurophysiology and Pathophysiology, Center of Experimental Medicine, University Medical Center Hamburg Eppendorf, University of Hamburg, Hamburg, Germany
PLoS ONE 2:e684. 2007.... - Steady-state visually evoked potential correlates of object recognitionKai Kaspar
University of Osnabruck, Institute of Cognitive Science, 49069 Osnabruck, Germany
Brain Res 1343:112-21. 2010..Thus, SSVEP paradigms open new venues to study object recognition. Nonetheless, selecting appropriate driving frequencies is non-trivial, because flicker rate might have an influence on the observed effects...