Zusammenfassung für den Vortrag am 16.01.2002 (16:15 Uhr)Seminar MATHEMATISCHE MODELLIERUNG BIOLOGISCHER SYSTEME
Lutz Schimansky-Geier (Humboldt Universität Berlin)
Tools of Stochastic Resonance and Synchronization Applied to Experiments with Paddlefish
We show that stochastic resonance can be interpreted as stochastic phase synchronization. Introducing a phase desccription to stochastic bistable dynamics we investigate conditions where strong phase relations are obeyed between an inputting signal and the stochastic output of the bistable dynamics. By considering dichotomic input and output signals we are able to analytically prove the occurrence of noise-induced frequency and phase locking. Regions of stochastic synchronization form Arnold tongues in the amplitude/noise intensity space. In the second part we apply concepts of stochastic synchronization to behavioural experiments on paddlefish. It was shown experimentally that juvenile paddlefish makes use of stochastic resonance during prey detection. We show an increase of the average phase locking period for subthreshold signals acting on the paddlefish rostrum in the neighbourhood of swarms yielding a source of external electrical noise. Literature: J. A. Freund, A. Neiman and L. Schimansky-Geier, Europhys. Lett. 50 8-14 (2000). J. A. Freund, J. Kienert, L. Schimansky-Geier, B. Beisner, A. Neiman, D. Russel, T. Yakusheva and F. Moss, Phys. Rev. E 63, 031910 1-11 (2001); Journal of Theoret. Biology, accepted for publication.