Annual Joseph Ford Commemorative Lecture: The Neuromechanics of Insect Locomotion: How Cockroaches Run Fast and Stably Without (much) Thought

I will describe several models for running insects, from an energy-conserving biped, through a muscle-actuated hexapod driven by a neural central pattern generator, to a reduced phase-oscillator model that captures the dynamics of unperturbed gaits and of impulsive perturbations. I will argue that both simple models and large simulations are necessary to understand biological systems.  The models show that piecewise-holonomic constraints due to intermittent foot contacts confer asymptotic stability on the feedforward system, while leg force sensors modulate motor outputs to mitigate large perturbations. Phase response curves and coupling functions help explain reflexive feedback mechanisms.  The talk will draw on joint work with Einat Fuchs, Robert Full, Raffaele Ghigliazza, Raghu Kukillaya, Josh Proctor, John Schmitt, and Justin Seipel. Research supported by NSF and the J. Insley Blair Pyne Fund of Princeton University.

Bio: 

Philip Holmes was born in England in 1945 and educated at the Universities of Oxford and Southampton. He taught at Cornell from 1977 to 1994, when he moved to Princeton, where he is a Professor of Mechanical and Aerospace Engineering and of Applied and Computational Mathematics and a member of Princeton's Neuroscience Institute. Much of his research has been in dynamical systems and their applications in engineering and the physical sciences, but in the past 15 years he has increasingly  turned to biology. He currently works on animal locomotion and the neuro-dynamics of decision making. He has also published four collections of poems (Anvil Press, London).