Meeting Abstract
Animals utilize neural control distributed across many muscles when tracking or navigating through natural environments. A growing body of evidence shows that temporal encoding is used to precisely time muscle activity in a variety of behaviors at many different speeds and in a diversity of animals. While encoding has been examined in single motor units, movement is actuated by muscles with different functions, and little is known about how information is encoded across multiple muscles. Previously, we recorded a spike-resolved motor program of unprecedented completeness in the hawk moth (Manduca sexta) as it tracked a robotic flower with a simple 1 Hz sinusoidal trajectory in tethered flight. We showed that both temporal and rate encoding mechanisms had significant mutual information with the flower’s position. We have now obtained the forces and torques produced during this behavior using a six-axis force-torque transducer and developed analysis that allows us to consider the net redundant or synergistic information across pairwise combinations of muscles. We show that both temporal and rate encoding mechanisms inform the turning (yaw) torque of the moth, and that the magnitude of temporally encoded information is higher than the magnitude of rate encoded information for all muscles. We demonstrate that pairwise combinations of muscles encode net redundant rather than synergistic information, and that most of this net redundant information is found in the temporal code. Finally, we find no evidence for differences in encoding strategy between putative flight power and steering muscles. These results indicate that motor encoding strategies may be consistent across muscles regardless of their different functional roles.
