J. J. Torres, J. Marro, P. L. Garrido, J. M. Cortes, F. Ramos and M. A. Munoz. Effects of static and dynamic disorder on the performance of neural automata. Biophysical Chemistry 115: 285-288, 2005 [pdf] We report on both analytical and numerical results concerning stochastic Hopfield-like neural automata exhibiting the following (biologically inspired) features: (1) Neurons and synapses evolve in time as in contact with respective baths at different temperatures; […]
Publications
151 posts
Sebastiano Stramaglia, Leonardo Angelini, Jesus M. Cortes and Daniele Marinazzo. Synergy, redundancy and unnormalized Granger causality. EMBS 4037-4040, 2015 [arXiv:1504.03584] [pdf]
S. Stramaglia, J.M. Cortes, L. Angelini, M. Pellicoro and D. Marinazzo. Information flow in Ising models on brain networks. V.M. Mladenov and P.C. Ivanov (Eds.): NDES 2014, CCIS 438, pp. 301–308, 2014 [pdf]. We analyze the information flow in the Ising model on two real networks, describing the brain at the mesoscale, with Glauber dynamics. We find that the critical state is characterized by the maximal amount of information flow […]
J. Hidalgo, L.F. Seoane, J.M. Cortes and M.A. Muñoz. Does the phenomenon of stochastic amplification of fluctuations play a relevant role in cortical dynamics? AIP Conference Proceedings 1510: 94-100, 2012 [pdf] We review the mechanism of stochastic amplification of fluctuations in the context of fast cortical oscillations observed during up-states both in vitro and in vivo. For this purpose, we employ minimalistic models based on short-time synaptic depression with or […]
A. Lopez, J.M. Cortes, D. Lopez-Oller, R. Molina and A.K. Katsaggelos. Hyperparameters Estimation for the Bayesian Localization of the EEG Sources with TV Priors. EUSIPCO 2012: 20th European Signal Processing Conference , pags 489-493, 2012 [pdf] In this work we propose a new Bayesian method for the non-invasive localization of EEG sources. For this problem, most of the existing methods assume that the sources are distributed throughout the brain volume […]
J.M. Cortes, D. Marinazzo, T.J. Sejnowski and M.C.W. van Rossum. The Direction of Tilt Aftereffects Depends on Short-term Inhibitory Facilitation. NIPS 2011, Submitted but Rejected [pdf] Neural adaptation leads to changes in the responses of single neurons and neural populations during continued exposure to a stimulus. At the single neuron level, adaptation reduces responses to a constant stimulus. At the perceptual level, adaptation can manifest itself as aftereffects. For instance, […]
J.M. Cortes. Interfaces cerebro-maquina, un gran paso hacia la Inteligencia Artificial. Ciencia Cognitiva: Revista Electronica de Divulgacion 3: 24-26, 2009 [pdf] Dentro de la Neurociencia Computacional, la Neuro-ingeniería desarrolla sistemas de comunicación entre una máquina y alguna parte del sistema nervioso. Sin lugar a dudas, estos sistemas constituyen un gran reto científico, ingenieril y ético. Sin embargo, su correcto funcionamiento todavía plantea muchos problemas.
J.M. Cortes. La Neurociencia Computacional hoy: I. Que es y por que es dificil su estudio. Ciencia Cognitiva: Revista Electronica de Divulgacion 3: 5-7, 2009 [pdf] La Neurociencia Computacional es una disciplina consolidada, con más de 20 años de desarrollo, y que emplea técnicas muy diversas para entender diferentes computaciones cerebrales. Aquí se introduce brevemente mediante dos artículos. En el primero, “Qué es y por qué es difícil su estudio”, […]
J.M. Cortes. La Neurociencia Computacional hoy: II. Un ejemplo muy representativo en el campo. Ciencia Cognitiva: Revista Electronica de Divulgacion 3: 8-11, 2009 [pdf] La Neurociencia Computacional es un campo reciente, pero bien establecido dentro de las Neurociencias. En un primer artículo Cortes 2009, “Qué es y por qué es difícil su estudio”, explico su principal paradigma: todo proceso mental que tiene lugar en nuestro cerebro tiene un circuito o […]
J.M.A.M. Kusters, J.M. Cortes, W.P.M. van Meerwijk, D.L.Ypey, A.P.R. Theuvenet and C.C.A.M. Gielen. Oscillatory activity in cells: multi-stability and hysteresis. AIP Conference Proceedings 887: 40-50, 2007 [pdf] Oscillatory activity of cells has been the topic of many studies. Oscillatory activity can be due to action potential firing corresponding to the well-known Hodgkin-Huxley (HH) type dynamics of ion-channels in the cell membrane or due to IP3-mediated calcium oscillations in the endoplasmic […]
J.J. Torres, J. M. Cortes and J. Marro. Information processing with unstable memories. AIP Conference Proceedings 887: 115-128, 2007 [pdf] We present a theoretical framework which allows one to study both theoretically and numerically the effect of including activity dependent mechanisms in the dynamics of synapses in simple neural networks. In particular, we study synaptic changes at different time scales from less than the millisecond (fast synaptic noise) to the […]
J.M. Cortes, A. Greve and M.C.W. van Rossum. Dynamical effects on familiarity discrimination. AIP Conference Proceedings 887: 217-223, 2007 [pdf] One process involved in recognition memory is familiarity discrimination. Familiarity distinguishes almost immediately after stimulus presentation whether the item was previously encountered (old) or novel. By using a formalism based on attractor neural networks, we discuss different dynamical processes affecting familiarity discrimination. First, we compare two different familiarity discriminators, the […]
J. Marro, J. M. Cortes and J. J. Torres. Discriminacion, generalizacion y clasificacion mediante automatas neuronales con ruido que induce depresion sinaptica. In CEDI2005, Ed. Thomson, pp. 335-341, 2005 ISBN:84-9732-444-7 [pdf] En una serie de trabajos recientes se estudian varias realizaciones de redes de neuronas artificiales que tienen aspectos notables. Se trata de algoritmos que, además de mostrar una memoria asociativa eficaz, son capaces de detectar similitudes (generalización) y diferencias […]
J.M. Cortes. Cooperative Phenomena in Stochastic Neural Networks with Dynamic Synapses. PhD Thesis, 2005. ISBN: 84-3383-291-3 [pdf]
D. Marinazzo, M. Pellicoro, G. Wu, L. Angelini, J.M. Cortes and S. Stramaglia. Information transfer of an Ising model on a brain network. Computational NeuroScience (CNS) 2013 Meeting. BMC Neuroscience 2013, 14(Suppl 1):P376 We consider an anatomical connectivity matrix (66 nodes), obtained via diffusion spectrum imaging (DSI) and white matter tractography [1], describing the brain at a coarse scale, and implement on it an Ising model with Glauber dynamics, estimating […]
A Erramuzpe, GJ Ortega, J Pastor, RG de Sola, D Marinazzo, S Stramaglia and JM Cortes. Redundancy and synergetic circuits in inter-ictal activity of human temporal lobe epilepsy. Society for Neuroscience Annual Meeting 2014. The use of information theory in neuroscience have allowed to evaluate the interaction between groups of correlated variables, revealing their functional role and underlying circuits capable of processing information (Borst and Theunissen, 1999, Nat Neurosci; Panzeri […]
A Erramuzpe, JM Encinas, A Sierra, M Maletic-Savatic, AL Brewster, AE Anderson, S Stramaglia and JM M Cortes. Variations in whole-brain functional connectivity across seizure chronification in a mouse model of mesial temporal lobe epilepsy. Society for Neuroscience Annual Meeting 2014. How does the brain become epileptic? Although this is a major question for modern Neurology, we do not have yet a proper answer. Despite of intense research in the […]
I. Ortega-Martinez, J. Gardeazabal, A. Erramuzpe, R. Fernandez-Suarez, E. Alonso-Tejerina, G. Perez-Yarza, J.M. Cortes, I.M. de la Fuente, A. Asumendi and M.D. Boyano. Serum Proteomics in Melanoma Biomarker Discovery. 13th Annual World Congress of the Human Proteome Organization 2014. Introduction and objectives Patients with early-stage melanoma and no lymph node involvement have a high likelihood of cure after complete excision of the tumor by surgery. However, there is no effective […]
J.M. Cortes, J. Goñi, M.A. Muñoz and D.R. Chialvo. Generic dynamics at criticality links brain structure to function. Frontiers in Neuroinformatics, 2013 [pdf] The relation, influence, and constraints between structure and function of the human brain is not yet well understood, even for the widely studied resting state. In the last decade, different topological descriptors, and dynamical models such as neural mass or more complicated coupling models have shown how […]
V. Maki-Marttunen, J.M. Cortes, M. Villareal and D.R. Chialvo. Disruption of transfer entropy and inter-hemispheric brain functional connectivity in patients with disorder of consciousness. Computational NeuroScience (CNS) 2013 Meeting. BMC Neuroscience 2013, 14(Suppl 1):P83 [pdf] CNS 2013 Best Student Poster Award Winner. Recent studies suggest that the functional organization of brain networks is altered in patients with severe disorders of consciousness (DOC), including coma [1]. A better characterization of these […]
J.M. Cortes, D. Marinazzo, P. Series, M.W. Oram, T.J. Sejnowski and M.C.W. van Rossum. Neural adaptation reduces energy cost while preserving coding accuracy. Society for Neuroscience Annual Meeting 2010 Neurons in the primary visual cortex initially respond vigorously when a preferred stimulus is presented, but typically adapt as stimulation continues. The functional consequences of adaptation are unclear. Typically a reduction of firing reduces single neuron accuracy, but it has been […]
J.M. Cortes, D. Marinazzo, P. Tudela and E. Madrid. Causal connectivity analysis of tracking faces in presence of repeated distractors during working memory tasks. Society for Neuroscience Annual Meeting 2009 Recognition of a specific visual target among equally familiar distracters requires neural mechanisms for tracking items in working memory. High Density EEG recordings were obtained from sixteen right-handed normal participants while they performed a visual working memory task in which […]
L. Mancera, R. Jimenez-Galan, J.M. Cortes. Visual Information Processing trough a simulated retina: Linear vs Bayesian reconstruction of natural movies. Society for Neuroscience Annual Meeting 2009 In vision neuroscience much of the knowledge about information processing comes from experiments in presence of highly reduced stimuli: orientated bars, drifting gratings or dots and sometimes combinations of them. Very often, the implicit linearity of the stimuli works quite well to explain linear […]
J.M. Cortes, D. Marinazzo, P. Series, M. Oram, T.J. Sejnowski and M.C.W. van Rossum. Heterogeneous adaptation effects on visual population coding efficiency. COSYNE 2008: 5th Computational and Systems Neuroscience Meeting The cellular and synaptic mechanisms underlying visual adaptation have extensively been debated during the last years (for reviews see Kohn 2007 and Schwartz 2007). However, the effect of neural adaptation on information coding is difficult to study experimentally as it […]
J. M. Cortes, P. L. Garrido, J. Marro and J. J. Torres. Switching between memories in neural automata with synaptic noise. Neurocomputing 58-60: 67-71, 2004 [pdf] We present a stochastic neural automata in which activity fluctuations and synaptic intensities evolve at different temperature, the latter moving through a set of stored patterns. The network thus exhibits various retrieval phases, including one which depicts continuous switching between attractors. The switching may […]
J.M. Cortes, T.J. Sejnowski and M.C.W. van Rossum. Reverse Engineering: Weight dynamics consistent with experimental weight distributions. Society for Neuroscience Annual Meeting 2007 The strengths of synaptic connections that are responsible for perception and memory change on time scales ranging from milliseconds to many days. A key question is how memories can be made stable over long periods of time despite the ongoing synaptic plasticity. The distribution of synaptic weights […]
D. Marinazzo, J.M. Cortes, M. Postlethwaite and M. Hennig. Synaptic depression and multi-scale phenomena. Society for Neuroscience Annual Meeting 2007 How short term plasticity (STP) affects synaptic transmission has been widely studied during the last decade (Zucker and Regehr, 2001). During repetitive stimulation, a postsynaptic response can be facilitated or depressed or shaped by a combination of both. These effects have been successfully explained by models focusing on two main […]
J.M.A.M. Kusters, A.P.R. Theuvenet, D.L. Ypey, W.P.M. van Meerwijk, J.M. Cortes and C.C.A.M. Gielen. Calcium Oscillations driving an excitable membrane: Hysteresis and Bi-stability. Biophysical Society: 51th Annual Meeting. Biophysical Journal 257A-257A Suppl. S, 2007 In normal rat kidney (NRK) fibroblasts the excitable membrane exhibits action potentials caused by an intracellular, IP3-mediated calcium oscillation (CaO). We modeled that process in detail and applied bifurcation analysis to investigate the dynamic behaviour of […]
J. J. Torres, J. M. Cortes and J. Marro. Instability of attractors in auto-associative networks with bio-inspired fast synaptic noise. Lecture Notes in Computer Science 3512: 161-167, 2005 [pdf] We studied auto–associative networks in which synapses are noisy on a time scale much shorter that the one for the neuron dynamics. In our model a presynaptic noise causes postsynaptic depression as recently observed in neurobiological systems. This results in a […]
J. M. Cortes, P. L. Garrido, H. J. Kappen, J. Marro, C. Morillas, D. Navidad and J. J. Torres. Algorithms for identification and categorization. AIP Conference Proceedings 779: 178-184, 2005 [pdf] This article reports on a series of efforts during the last decade aimed at modeling in a computer the cooperative properties that, according to some experimental evidence, could be relevant for the processing of patterns in a brain. In […]