Meeting Abstract
Legged locomotion requires control of numerous complex coupled systems, yet strategies employed by animals such as cockroaches allow for robust navigation through varied environments. As animals move faster, one might expect that the need for coordination becomes more important but that centralizing control is made more difficult due to limiting bandwidth. Here we expand on previous work on using mutual information (MI) as a metric for centralization to test the hypothesis that faster locomotion leads to a more centralized control architecture. In the cockroach Blaberus discoidalis, we estimate the MI between leg control signals and two kinematic state variables: a local measure of leg extension and a global measure of the overall limb kinematics. MI informs how much the control signal reduces the possible variability in the output variable and vice versa without assumptions of a particular model. We section a large data set of cockroaches running on flat terrain by stride frequency. The degree of centralization, as quantified by the amount of global MI minus the local MI, peaks at an intermediate stride frequency that corresponds to the previously published preferred running speed. Therefore, while centralization may have increasing benefits with speed, there is evidence that coordinating control becomes less attainable due to bandwidth constraints.
