Hybrid sensorimotor performance

Our team uses hybrid systems, which mix biological control with artificial devices, in order to (i) increase our understanding of sensorimotor control and (ii) exploit this knowledge to restore and optimize movement. Instead of being pre-programmed in the brain, movement coordination largely depends upon multiple feedback loops that operate at different levels of the sensorimotor control system. For instance, muscle mechanics provides an instantaneous functional response to small perturbations, while segmental and transcortical reflexes are able to absorb increasingly larger perturbations by precisely coordinating muscle responses for the complex musculoskeletal design of our limbs. These loops are typically violated in the case of artificial devices, such as with prosthetic limbs whose biomechanics differs from that of original limbs, and which lack sensory feedback. We use a range of closed loop hybrid systems to investigate how these lower feedback loops interact with limb’s biomechanics, how they contribute to the production of normal, coordinated movements, and how to improve the design of hybrid control strategies to restore movements.