Meeting Abstract
Neural systems mediate robust sensory processing and adaptive feedback for locomotor control in animals. We developed a method to investigate adaptive responses to changes in locomotion dynamics in the glass-knifefish, Eigenmannia virescens. These fish perform a refuge-tracking task in which a refuge is moved by a precision motor system. In previous studies, we used this system to move the refuge sinusoidally at frequencies between 0.01 and 2 Hz for open-loop system identification of the fish tracking response. Here we developed a control system that allows us to generate dynamic movement of the refuge in relation to the fish’s motion (tracked in real time from a live video feed). In this way, we alter the sensory consequences, via an experimentally determined transfer function, of the fish’s own movement in a closed-loop paradigm. This dynamic feedback can be added to sinusoidal input signals to enable system identification while the fish is experiencing experimentally modified locomotion dynamics. Our hypothesis is that changes in locomotor dynamics will trigger adaptive responses in the fish’s tracking performance. Further, we expect to observe a post-adaptation period, where the fish regains its original controller after the novel dynamics are removed. Preliminary results with sum-of-sines system identification support our hypothesis by exhibiting a decrease in fish’s gain in response to some frequency bands and recovering the gain when the “novel locomotion dynamics” are removed. The data suggests that we can trigger and monitor adaptation and post-adaptation responses of a fish by using closed-loop feedback control system.
