Mammalian locomotion is generated by central pattern generators (CPGs) in the spinal cord, which produce alternating flexor and extensor activities controlling the locomotor movements of each limb. Afferent feedback signals from the limbs are integrated by the CPGs to provide adaptive control of locomotion. Responses of CPG-generated neural activity to afferent feedback stimulation have been previously studied during fictive locomotion in immobilized cats. Yet, locomotion in awake, behaving animals involves dynamic interactions between central neuronal circuits, afferent feedback, musculoskeletal system, and environment. To study these complex interactions, we developed a model simulating interactions between a half-center CPG and the musculoskeletal system of a cat hindlimb. Then, we analyzed the role of afferent feedback in the locomotor adaptation from a dynamic viewpoint using the methods of dynamical systems theory and nullcline analysis. Our model reproduced limb movements during regular cat walking as well as adaptive changes of these movements when the foot steps into a hole. The model generates important insights into the mechanism for adaptive locomotion resulting from dynamic interactions between the CPG-based neural circuits, the musculoskeletal system, and the environment.
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An Adaptive Frequency Central Pattern Generator for Synthetic Nervous Systems
Generators (CPGs) are being used for controlling the complicated gaits and timing required for stable walking. Traditionally, these models are precisely designed for oscillation at a set of specific frequencies and phase relationships, which while easier to design is not conducive to robust and stable walking. In recent years, work has been done on designing adaptive models of CPGs. These CPGs are able to exhibit complex behaviors such as learning the resonant dynamics of a system to improve walking stability, as well as using mathematical learning rules to learn arbitrary signals and embed their relationships within the system. This work explores the possibility of implementing an adaptive frequency CPG with a similar behavior to these systems, using conductance-based models of dynamic non-spiking neurons connected as a synthetic nervous system (SNS).
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- Award ID(s):
- 1704436
- PAR ID:
- 10076340
- Date Published:
- Journal Name:
- Lecture notes in computer science
- Volume:
- 10928
- ISSN:
- 1611-3349
- Page Range / eLocation ID:
- 361-364
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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