Berlin 2012 – scientific programme
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BP: Fachverband Biologische Physik
BP 18: Posters: Statistical Physics in Biological Systems
BP 18.34: Poster
Wednesday, March 28, 2012, 17:30–19:30, Poster A
Describing non-linear attentional modulation patterns through ring-architecture neural circuits — •Markus Helmer1,4, Vladislav Kozyrev2,3, Stefan Treue2,4, Theo Geisel1,4, and Demian Battaglia1,4 — 1Max Planck Institute for Dynamics and Self-Organization, Göttingen — 2Deutsches Primatenzentrum, Göttingen — 3Institute of Neuroinformatics, Ruhr-University Bochum — 4BCCN, Göttingen
We analyzed recordings in area MT from macaque monkeys performing a transparent motion task. They were presented random-dot-patterns (RDP) at two distinct locations within the receptive field of the recorded cell. Attention was directed to a fixation spot or to only one of the two RDPs. The angle between the two RDPs was kept fixed at 120 degrees so that covarying the motion directions provided tuning curves with two peaks. We found that the positions of the response peaks were different from what the single-motion orientation-preferences of the cell predicted. Furthermore they depended on the attentional condition, showing strong signatures of non-linear interactions during the integration of the two stimuli by MT neurons, including peak repulsion or attraction. By using a mean-field ring model, we could reproduce all the observed response non-linearities independently in broad regions of the parameter space. However, to find the specific combination of non-linearities observed across attentional conditions a fine tuning of the parameters was required. We explored therefore multi-areal network models with multiple coupled rings to achieve a more robust description of non-linear attentional modulation patterns.