Postdoctoral Associate Researcher
Carnegie Mellon University,
Department of Biological Sciences and
Center for the Neural Basis of Cognition
Mellon Institute, 4400 Fifth Avenue
Pittsburgh PA 15213, USA
Phone: (001) 412 268 9818 rfgalan@gmail.com
I studied Physics at the Universidad Autónoma de Madrid and got my PhD in Theoretical Biophysics at the Humboldt Universität zu Berlin. Currently I am a postdoctoral researcher in the groups of Nathan Urban (Biology, Carnegie Mellon University) and Bard Ermentrout (Mathematics, University of Pittsburgh). Combining theoretical and experimental approaches we are studying how the characteristic network dynamics of the mammalian olfactory bulb emerge from the interactions between neurons and how such neural dynamics encode odor information.
Recently we have described a general biophysical mechanism for generating network oscillations, namely stochastic synchronization, that may account for the beta/gamma oscillations observed in the olfactory system [more]. Stochastic synchronization is related to the widely studied phenomenon of spike-time reliability[more].
Beyond stochastic approaches we are also interested in deterministic models of neural dynamics. In particular, we have recently shown how to reduce the complex dynamics of real neurons (mitral cells) to simple phase models without losing relevant information. This requires the experimental estimation of phase-resetting curves from real neurons [more]. Our studies on phase models reveal that the formation of synchronized neural assemblies is a rather general phenomenon in neural networks [more]. Also, phase models allow us to investigate stochastic phenomena in neural networks using a combination of Fokker-Planck theory with the finite element method [more].
In my PhD-thesis I have shown that the network dynamics of the antennal lobe -the analogue of the olfactory bulb in insects- possess odor-specific attractors. This property allows not only for a simple encoding mechanism of odors into neural activity but also for a straightforward decoding mechanism in downstream neural networks [more]. I have also provided evidence of Hebbian reverberations in the antennal lobe that store odor information for a short term. In particular, the odor information is stored in correlations between spontaneously active neural units after stimulation [more]. This form of memory trace enables the retrieval of the last odor presented to the animal with a principal-component analysis. [Dissertation]
Roberto F. Galán, G. Bard Ermentrout and Nathaniel N. Urban (2008). Optimal time scale for spike-time reliability:
Theory, simulations and experiments. Journal of Neurophysiology, 99, p.277-283. Key words: colored noise, spike-triggered average, Liapunov exponent, patch-clamp, cross-correlation, stochastic synchronization.
[PDF preprint]
Roberto F. Galán, G. Bard Ermentrout and Nathaniel N. Urban (2007). Stochastic dynamics of uncoupled neural oscillators: Fokker-Planck studies with the finite element method. Physical Review E, 76, 056110. Key words: correlated noise, stochastic synchronization, neuronal reliability, integrators, resonators, phase-response curve.
[PDF preprint]
G. Bard Ermentrout, Roberto F. Galán and Nathaniel N. Urban (2007). Relating neural dynamics to neural coding. Physical Review Letters, 99, 248103. Key words: phase-response curve, spike-triggered average, stimulus encoding, neural oscillator. [PDF]
J. L. Pérez Velázquez, R. F. Galán, L. García Domínguez, Y. Leshchenko, S. Lo, J. Belkas, and R. Guevara Erra (2007). Phase response curves in the characterization of epileptiform activity. Physical Review E, 76, 061912. Key words: phase oscillator, Kuramoto model, absence seizure, petit mal, thalamocortical coupling. [PDF]
Roberto F. Galán, G. Bard Ermentrout and Nathaniel N. Urban (2007). Reliability and stochastic synchronization in type I vs. type II neural oscillators. Neurocomputing, 70, p.2102-2106.
Key words: phase-resetting curve, phase models, correlated noise, integrator, resonator.
[PDF preprint]
Roberto F. Galán, Nicolas Fourcaud, G. Bard Ermentrout and Nathaniel N. Urban (2006). Correlation-induced synchronization of oscillations in olfactory bulb neurons. Journal of Neuroscience, 26(14), p.3646-3655.
Key words: stochastic synchrony, gamma oscillations, correlated noise, olfaction.
[PDF preprint]
Roberto F. Galán, G. Bard Ermentrout and Nathaniel N. Urban (2006). Predicting synchronized neural assemblies from experimentally estimated phase-resetting curves. Neurocomputing, 69(10-12), p.1112-1115.
Key words: phase-resetting curve, phase models, cell assemblies, symmetry breaking, synchrony.
[PDF preprint]
Roberto F. Galán, G. Bard Ermentrout and Nathaniel N. Urban (2006). Reliability, discriminability and noise-induced synchronization of olfactory neurons. Sensors and Actuators B: Chemical, 116(1-2), p.168-173.
Key words: artificial nose, correlated stochastic inhibition, olfaction.
[PDF preprint]
Roberto F. Galán, G. Bard Ermentrout and Nathaniel N. Urban (2005). Efficient estimation of phase-resetting curves in real neurons and its significance for neural-network modeling. Physical Review Letters, 94, 158101. Key words: phase-resetting curve, phase models, patch clamp, mitral cells, synchrony.
[PDF preprint]. This work has been chosen by Scientific American as one of fifty emerging trends in research, business and policy in 2005: “Watching the brain at work" by Michael Szpir, Scientific American, December 2005, p.62. [PDF article]
Roberto F. Galán, Marcel Weidert, Randolf Menzel, Andreas V.M. Herz and C. Giovanni Galizia (2006). Sensory memory for odors is encoded in spontaneous correlated activity between olfactory glomeruli. Neural Computation 18(1), p.10-25.
Key words: Hebbian learning, memory trace, calcium imaging, antennal lobe, correlation analysis, principal component.
[PDF preprint]
Roberto Fdez. Galán, Silke Sachse, C. Giovanni Galizia and A.V.M. Herz
(2004). Odor-Driven Attractor Dynamics in the Antennal Lobe Allow for
Simple and Rapid Olfactory Pattern Classification. Neural Computation 16(5), p.999-1012.
Key words: neural dynamics, sensory coding, support-vector machine.
[PDF preprint]
R. Fdez. Galán, R. Ritz, P. Szyszka and A.V.M. Herz (2004). Uncovering
short-time correlations between multichannel recordings of brain activity: A Phase-Space Approach. International Journal of Bifurcations and Chaos 14(2), p.585-597. Key words: multidimensional phase coupling, correlated neural activity, multivariate time series analysis. [PDF preprint]
R. Ritz, R. Fdez. Galán, P. Szyszka and A.V.M. Herz (2001). Analysis of
odor processing in the mushroom bodies of the honeybee. Neurocomputing
38-40, p.313-318. Key words: bee brain, olfaction, local field potential, wavelet and correlation analysis.
Online
Roberto Fernández Galán (2003). Odor Coding and Memory Traces in the Antennal Lobe of Honeybee:
Computational Studies of Neural Dynamics based on Calcium-Imaging Data. PhD-thesis edited by the
documentation server of the Humboldt University, Berlin. Key words: neural dynamics, sensory coding, perceptron, Hebbian reverberations, short-term memory, neural plasticity, calcium-imaging.
[PDF file]
Proceedings and Symposia
Roberto Fernández Galán, G. Bard Ermentrout and Nathaniel N. Urban (2007). Cell-intrinsic and stimulus properties that maximize spike-time reliability and stochastic synchronization, Program No. 761.10. 2007 Neuroscience Meeting Planner. San Diego, CA: Society for Neuroscience, 2007. Online. [PDF abstract]. SfN 36th Annual Meeting, November 3-7, 2007. [PDF presentation]
Roberto Fernández Galán (2007). Applicability and limitations of the phase-oscillator approximation in neuroscience [PDF presentation]. Workshop on "Synchronization of brain signals: what is real, what is not" at the Computational Neuroscience Conference, CNS 2007, Toronto, Canada.
Roberto Fernández Galán, G. Bard Ermentrout and Nathaniel N. Urban (2007). Stochastic synchronization in type I vs type II neural oscillators: Fokker-Planck studies with the finite element method [PDF abstract]. Computational Neuroscience Conference, CNS 2007, Toronto, Canada. [PDF poster]
Roberto Fernández Galán, G. Bard Ermentrout and Nathaniel N. Urban (2007). Optimal time scale for spike-time reliability and stochastic synchronization: Theory, simulations and experiments. SIAM Conference on Applications of Dynamical Systems. Snowbird, Utah, May 27-June 1, 2007. [PDF presentation]
Roberto Fernández Galán, G. Bard Ermentrout and Nathaniel N. Urban (2006). Optimal time scale for response reliability and stochastic synchronization in real neurons, Program No. 432.4. 2006 Neuroscience Meeting Planner. Atlanta, GA: Society for Neuroscience, 2006. Online. [PDF abstract]. SfN 36th Annual Meeting, October 14-18, 2006. [PDF poster]
Roberto Fernández Galán (2006). Emergence of Brain Rhythms from Noise [PDF presentation]. Invited talk at the retreat of the CNUP (Center for Neuroscience University of Pittsburgh), Oglebay, West Virginia, USA.
Roberto Fernández Galán (2006). Neural dynamics in the antennal lobe: Sensory coding and memory traces in an insect´s brain [PDF presentation]. SIAM Conference on Life Sciences 2006, Raleigh, North Carolina, USA.
Roberto F. Galán, G. Bard Ermentrout and Nathaniel N. Urban (2006). Phase-response curve: predicting network dynamics from a single cell feature [PDF presentation]. Workshop on phase-response curves. Computational Neuroscience Conference, CNS2006, Edinburgh, UK.
Roberto F. Galán, G. Bard Ermentrout and Nathaniel N. Urban (2006). Reliability and stochastic synchronization in type I vs. type II neural oscillators [PDF abstract]. Computational Neuroscience Conference, CNS 2006, Edinburgh, UK. [PDF poster]
Roberto Fernández Galán, G. Bard Ermentrout and Nathaniel N. Urban (2005). Constructing phase models of biological neural networks from experimentally estimated phase-response curves, Program No. 274.3. 2005 Abstract Viewer/Itinerary Planner. Washington, DC: Society for Neuroscience, 2005. Online. [PDF abstract]. SfN 35th Annual Meeting, November 12-16, 2005. [PDF poster]
Roberto F. Galán, G. Bard Ermentrout and Nathaniel N. Urban (2005). Predicting synchronized neural assemblies from experimentally estimated phase-resetting curves [PDF abstract]. Computational Neuroscience Conference, CNS 2005, Madison, Wisconsin. Winner of an Outstanding Presentation Award. [PDF presentation]
Roberto Fernández Galán, G. Bard Ermentrout and Nathaniel N. Urban (2005). Reliability, discriminability and noise-induce synchrony in olfactory neurons [PDF preprint]. International Symposium on Olfaction and Electronic Nose, Barcelona, Spain 2005. [PDF presentation]
Roberto Fernández Galán (2005). Pattern Recognition and Hebbian Learning in Olfactory Processing:
Lessons from an Insect’s Brain [PDF preprint]. International Symposium on Olfaction and Electronic Nose, Barcelona, Spain 2005. [PDF presentation]
Roberto Fernández Galán, Marcel Weidert, Randolf Menzel, Andreas Herz, Giovanni Galizia (2004). Hebbian reverberations in an insect's brain [PDF poster]. Statistical Analysis of Neuronal Data, Pittsburgh 2004.
R. Fdez. Galán, M. Weidert, R. Menzel, A.V.M. Herz and C. G. Galizia
(2004). Sensory memory of odors is encoded in correlations between olfactory glomeruli. Berlin Neuroscience Forum 2004.
R. Fdez. Galán, M. Weidert, A.V.M. Herz, R. Menzel and C. G. Galizia
(2003). Dissecting the olfactory code: A working memory trace in the bee antennal
lobe. PDF poster created by
Giovanni Galizia. Zweites Symposium der Volkswagenstiftung über “Dynamics and Adaptivity of Neuronal Systems. Integrative Approaches to Analyzing Cognitive Functions”, Magdeburg 2003
R. Fdez. Galán, S. Sachse, C. G. Galizia and A.V.M. Herz (2003). Odor driven
Calcium Dynamics in the Antennal Lobe of Honeybee: A Hypothesis
about the Olfactory Code [PDF poster]. Proceedings of the 29th Göttingen Neurobiology Conference.
M. Weidert, R. Fdez. Galán, C. G. Galizia, A.V.M. Herz and R. Menzel
(2003). Odor stimulation induces changes of correlation between glomeruli
in the Antennal Lobe of the Honeybee. Proceedings of the 29th Göttingen
Neurobiology Conference.
R. Fdez. Galán, R. Ritz, P. Szyszka and A.V.M. Herz (2002). Detecting Correlations
in Multisite Recordings of Nonstationary Brain Activity. Attractors,
Signals and Synergetics: Proceedings of the 1st European Interdisciplinary
School on Nonlinear Dynamics for System and Signal Analysis (Euroattractor
2000). W. Klonowski (Editor). Pabst Science Publishers.
R. Fdez. Galán, R. Ritz, P. Szyszka and A.V.M. Herz (2001). Detecting
Correlations between Nonstationary Brain Signals [PDF poster]. Proceedings of the 28th Göttingen Neurobiology Conference [PDF abstract]
My work in Physical Review Letters with Bard Ermentrout and Nathan Urban has been chosen by Scientific American as one of the fifty emerging trends in research, business and policy in 2005: "Watching the brain at work" by Michael Szpir, Scientific American, December 2005, p.62. [PDF article]
"Team led by Carnegie Mellon University scientist finds first evidence of a living memory trace. Results show neural reorganization occurs during short-term memory", by Lauren Ward, EurekAlert!, November 14, 2005.
"Fearful symmetry: Probing the limits of brain modeling", by Fred Hapgood,
Cerebrum, the Dana forum on brain science, Vol. 7(3),Summer 2005.
"Carnegie Mellon and U. of Pittsburgh create tool to understand neuron rhythms, learning. Work will aid neural-network modeling, studies of learning and disease", by Lauren Ward, EurekAlert!, April 11, 2005.
"Organised chaos gets robots going", by Will Knight, New Scientist, November 1, 2004 (interviewed about the work by Kuniyoshi and Suzuki, “Dynamic emergence and adaptation of behavior through embodiment as coupled chaotic field”, IEEE, Proceedings of 2004 IEEE/RSJ International Conference on Intelligent Robots and Systems).
