Instantaneous kinematic phase reflects neuromechanical response to lateral perturbations of running cockroaches

• Published in: Biological cybernetics 2013-04, Vol.107 (2), p.179-200
• Main Authors: Revzen, Shai, Burden, Samuel A., Moore, Talia Y., Mongeau, Jean-Michel, Full, Robert J.
• Format: Article
• Language: English
• Subjects: Animals; Applied sciences; Bioinformatics; Biological and medical sciences; Biomechanical Phenomena; Biomechanics; Biomedical and Life Sciences; Biomedicine; Blaberus discoidalis; Cell physiology; Cockroaches - physiology; Complex Systems; Computer Appl. in Life Sciences; Computer science; control theory; systems; Computer systems and distributed systems. User interface; Control theory. Systems; Cybernetics; Electromyography; Evoked Potentials, Motor; Exact sciences and technology; Feedback, Physiological - physiology; Functional Laterality - physiology; Fundamental and applied biological sciences. Psychology; Insects; Kinematics; Modelling and identification; Models, Biological; Molecular and cellular biology; Muscle contraction; Muscle, Skeletal; Neurobiology; Neurosciences; Nonlinear Dynamics; Original Paper; Periodicity; Peripheral nervous system. Autonomic nervous system. Neuromuscular transmission. Ganglionic transmission. Electric organ; Postural Balance - physiology; Running - physiology; Software; Vertebrates: nervous system and sense organs
• ISSN: 0340-1200; 1432-0770
• DOI: 10.1007/s00422-012-0545-z

Instantaneous kinematic phase calculation allows the development of reduced-order oscillator models useful in generating hypotheses of neuromechanical control. When perturbed, changes in instantaneous kinematic phase and frequency of rhythmic movements can provide details of movement and evidence for neural feedback to a system-level neural oscillator with a time resolution not possible with traditional approaches. We elicited an escape response in cockroaches ( Blaberus discoidalis ) that ran onto a movable cart accelerated laterally with respect to the animals’ motion causing a perturbation. The specific impulse imposed on animals (0.50 0.04 m s ; mean, SD) was nearly twice their forward speed (0.25 0.06 m s . Instantaneous residual phase computed from kinematic phase remained constant for 110 ms after the onset of perturbation, but then decreased representing a decrease in stride frequency. Results from direct muscle action potential recordings supported kinematic phase results in showing that recovery begins with self-stabilizing mechanical feedback followed by neural feedback to an abstracted neural oscillator or central pattern generator. Trials fell into two classes of forward velocity changes, while exhibiting statistically indistinguishable frequency changes. Animals pulled away from the side with front and hind legs of the tripod in stance recovered heading within 300 ms, whereas animals that only had a middle leg of the tripod resisting the pull did not recover within this period. Animals with eight or more legs might be more robust to lateral perturbations than hexapods.