Berlin 2008 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 30: Nonlinear stochastic systems

DY 30.7: Vortrag

Freitag, 29. Februar 2008, 11:45–12:00, MA 001

Noise-induced synchronisation in heterogeneous nets of neural elements — •Erik Glatt, Martin Gassel, and Friedemann Kaiser — Institute of Applied Physics, Darmstadt University of Technology, 64289 Darmstadt, Germany

Noise may have a strong influence on the dynamics of many spatially extended nonlinear systems. Variability (diversity, heterogeneity), where variability denotes static stochastic differences between otherwise equal elements of a system, may have similar effects. In this contribution the interplay of additive noise and additive variability in an oscillatory net of FitzHugh-Nagumo elements is studied. Both have a crucial influence on the phase synchronisation of the elements in the net. It is shown that additive variability induces pattern formation (phase waves) and hence even small values of the variability strength destroy the synchronised oscillation the net exhibits without variability. In such a heterogeneous net the synchronisation can be restored via additive noise. This noise-induced phase synchronisation exhibits a resonance-like dependency on the noise strength.

The variability-induced pattern formation is again a resonance-like effect provided additive noise is present in the net. In this case one finds maximally coherent patterns for intermediate values of the variability strength.