March 12 (Thursday) Greg Stephens (Princeton University)
Title: More bits for behavior: From C elegans movement toward the principles of animal action
Abstract:
A major challenge in analyzing animal behavior is to discover some underlying simplicity in complex motor actions. Here we show that the space of shapes adopted by the nematode C. elegans is surprisingly low dimensional, with just four dimensions accounting for 95% of the shape variance. These "eigenworms" provide a complete, quantitative description of worm behavior and we partially reconstruct equations of motion for the dynamics in this space. The reconstructed dynamics contain multiple attractors, revealing novel pause states and we find that the worm visits these in a rapid and almost completely deterministic response to weak thermal stimuli. Stimulus dependent correlations among the different modes suggest that one can generate more reliable behaviors by synchronizing stimuli to the state of the worm in shape space. We confirm this prediction, effectively“steering” the worm in real time.