Regensburg 2010 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 21: Neurobiophysics and Sensory Transduction
BP 21.7: Vortrag
Mittwoch, 24. März 2010, 16:00–16:15, H43
Controlling effective connectivity between cortical areas via collective dynamics transitions — •Demian Battaglia1,3, Annette Witt1,2,3, Theo Geisel1,3, and Fred Wolf1,3 — 1Max Planck Institute for Dynamics and Self-Organization, Göttingen — 2German Primate Center, Göttingen — 3Bernstein Center for Computational Neuroscience, Göttingen
Anatomic connections between cortical areas constrain the spatio-temporal complexity of brain rhythmic activity. However, structural connectivity does not coincide with effective connectivity, related to the more elusive question: Which areas cause the activity of which others? Effective connectivity is directed and task-dependent. Its fast changes are incompatible with the slow variation of anatomical connections in a mature brain.
We propose here a theory of controllable rewiring of effective connectivity based on dynamical transitions in the collective organization of neural activity. We consider small network motifs of interacting cortical areas, modeled first as mean-field rate units and then as large populations of spiking neurons. Even when the underlying structural networks are fully symmetric, we obtain chaotic dynamical configurations which spontaneously break the permutation symmetry between areas. Different dynamical configurations are shown to correspond to different causality flows when probed by tools like Granger Causality, Mutual Information or the better performing Transfer Entropy. Fully symmetric structural networks can thus give rise to multiple selectable effective connectivities with reduced symmetry.