Nelson J Trujillo-Barreto

Summary

Affiliation: 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

  1. ncbi request reprint Biophysical model for integrating neuronal activity, EEG, fMRI and metabolism
    Roberto 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
  2. pmc Processing of abstract rule violations in audition
    Erich Schroger
    Institute of Psychology I, University of Leipzig, Leipzig, Germany
    PLoS ONE 2:e1131. 2007
  3. ncbi request reprint Multiple sparse priors for the M/EEG inverse problem
    Karl Friston
    The Wellcome Trust Centre for Neuroimaging, Institute of Neurology, UCL, 12 Queen Square, London, WC1N 3BG, UK
    Neuroimage 39:1104-20. 2008
  4. doi request reprint Sources of synchronized induced Gamma-Band responses during a simple object recognition task: a replication study in human MEG
    T Gruber
    Institute for Psychology I, University of Leipzig, Leipzig, Germany
    Brain Res 1196:74-84. 2008
  5. pmc Diffusion-based spatial priors for functional magnetic resonance images
    L M Harrison
    Wellcome Trust Centre for Neuroimaging, UCL, London, UK
    Neuroimage 41:408-23. 2008
  6. doi request reprint DEM: a variational treatment of dynamic systems
    K J Friston
    The Wellcome Department of Imaging Neuroscience, University College London, United Kingdom
    Neuroimage 41:849-85. 2008
  7. doi request reprint Rapid extraction of auditory feature contingencies
    Alexandra Bendixen
    Institute for Psychology I, University of Leipzig, Germany
    Neuroimage 41:1111-9. 2008
  8. doi request reprint Early correlates of visual awareness in the human brain: Time and place from event-related brain potentials
    Urte Roeber
    Institute for Psychology I, University of Leipzig, Leipzig, Germany
    J Vis 8:21.1-12. 2008
  9. doi request reprint Early correlates of visual awareness following orientation and colour rivalry
    Sandra Veser
    Institute of Psychology I, Leipzig University, Seeburgstr 14 20, 04103 Leipzig, Germany
    Vision Res 48:2359-69. 2008
  10. doi request reprint Identification and comparison of stochastic metabolic/hemodynamic models (sMHM) for the generation of the BOLD signal
    Roberto 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

Detail Information

Publications30

  1. ncbi request reprint Biophysical model for integrating neuronal activity, EEG, fMRI and metabolism
    Roberto 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...
  2. pmc Processing of abstract rule violations in audition
    Erich 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...
  3. ncbi request reprint Multiple sparse priors for the M/EEG inverse problem
    Karl 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...
  4. doi request reprint Sources of synchronized induced Gamma-Band responses during a simple object recognition task: a replication study in human MEG
    T 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...
  5. pmc Diffusion-based spatial priors for functional magnetic resonance images
    L 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...
  6. doi request reprint DEM: a variational treatment of dynamic systems
    K 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)...
  7. doi request reprint Rapid extraction of auditory feature contingencies
    Alexandra 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...
  8. doi request reprint Early correlates of visual awareness in the human brain: Time and place from event-related brain potentials
    Urte 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...
  9. doi request reprint Early correlates of visual awareness following orientation and colour rivalry
    Sandra 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...
  10. doi request reprint Identification and comparison of stochastic metabolic/hemodynamic models (sMHM) for the generation of the BOLD signal
    Roberto 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...
  11. doi request reprint BET differences among simultaneous evoked frequency band responses during early-stage visual processing distinguish schizophrenia from healthy subjects
    J 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...
  12. doi request reprint Random fields--union intersection tests for detecting functional connectivity in EEG/MEG imaging
    Felix 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...
  13. doi request reprint ERP generator anomalies in presymptomatic carriers of the Alzheimer's disease E280A PS-1 mutation
    Maria A Bobes
    Cognitive Neuroscience Department, Cuban Center for Neuroscience, Havana, Cuba
    Hum Brain Mapp 31:247-65. 2010
    ....
  14. ncbi request reprint Bayesian M/EEG source reconstruction with spatio-temporal priors
    Nelson 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...
  15. pmc Diffusion-based spatial priors for imaging
    L 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...
  16. ncbi request reprint 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...
  17. ncbi request reprint [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...
  18. ncbi request reprint Bayesian model averaging in EEG/MEG imaging
    Nelson J Trujillo-Barreto
    Cuban Neuroscience Center, Havana, Cuba
    Neuroimage 21:1300-19. 2004
    ....
  19. ncbi request reprint Bayesian fMRI time series analysis with spatial priors
    William 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...
  20. ncbi request reprint Brain electrical tomography (BET) analysis of induced gamma band responses during a simple object recognition task
    Thomas Gruber
    Universitat Leipzig, Institut fur Psychologie I, Seeburgstrasse 14 20, 04103 Leipzig, Germany
    Neuroimage 29:888-900. 2006
    ....
  21. ncbi request reprint Mechanisms for detecting auditory temporal and spectral deviations operate over similar time windows but are divided differently between the two hemispheres
    Sabine 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...
  22. ncbi request reprint Variational free energy and the Laplace approximation
    Karl 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...
  23. ncbi request reprint Repetition suppression of induced gamma band responses is eliminated by task switching
    Thomas 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...
  24. ncbi request reprint Bayesian comparison of spatially regularised general linear models
    Will 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...
  25. ncbi request reprint Sustained spatial attention to vibration is mediated in primary somatosensory cortex
    C 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...
  26. ncbi request reprint Realistically coupled neural mass models can generate EEG rhythms
    Roberto 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...
  27. ncbi request reprint Modelling the role of excitatory and inhibitory neuronal activity in the generation of the BOLD signal
    Roberto 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)...
  28. pmc Directed cortical information flow during human object recognition: analyzing induced EEG gamma-band responses in brain's source space
    Gernot 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
    ....
  29. doi request reprint Steady-state visually evoked potential correlates of object recognition
    Kai 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...