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Johann Bernoulli Colloquium, John Hertz

16 november 2011

Speaker:John Hertz

Nordita, Stockholm and Niels Bohr Institute, Copenhagen

Title: Inference and the Inverse Ising Model

Date:Wednesday, November 16th, 2011

Room:5161.0267 (Bernoulliborg)

Time:16.15-Join us for coffee and tea at 15:45


An important current problem in neuroscience is inferring connectivity in neuronal networks from recordings of spike trains of many neurons.To do this, one chooses a stochastic dynamical model for the network and fits its parameters, including connection strengths, using the data.In the approach described here, the model chosen to make the fit with is probably the simplest one that captures generic features of the way neurons work: a dynamical Ising (Glauber) model, in which the “up” state represents neuronal firing and the interaction matrix Jij (which need not be symmetric) describes the synapses.Normally in theoretical statistical physics we are given a model, specified by some parameters, and the problem is to compute average values of observable quantities.Here we have an inverse problem:We have the measured statistics, and the task is to infer the parameters of the model.This talk will review recent work on this problem, including exact and mean-field algorithms and applying them to simulated and experimental neurobiological data.

John Hertz received his PhD from the University of Pennsylvania in 1970.He has worked at the Cavendish Laboratory, Cambridge, and the University of Chicago. He became Professor at Nordita in 1980.Since 2007 he has also been Professor at the Niels Bohr Institute.

He has worked in condensed matter theory and the statistical mechanics of disordered systems, especially spin glasses.In recent years his focus has been on biological networks, particularly neural networks in the neocortex.His current work deals with inferring network connectivity from multineuron spike data.

Colloquium coordinators Mathematics are Prof.dr. A.C.D. van Enter (e-mail : and Dr. A.V. Kiselev (e-mail:

Colloquium coordinators Computer Science are Prof.dr. M. Aiello (e-mail: and Prof.dr. M. Biehl (e-mail:

Laatst gewijzigd:06 juni 2018 13:58

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