Meeting Abstract
Animals routinely produce movements whose express purpose is to obtain sensory information, a process known as active sensing. To examine active sensing, we investigated Eigenmannia virescens as they performed a robust refuge tracking behavior using visual and electrosensory inputs. When tracking a refuge in the dark, the fish performs fore-aft oscillatory motions (i.e. active sensing) which shape spatiotemporal patterns of electrosensory feedback. Our hypothesis is that fish adapt these motions to maintain salient electrosensory feedback while tracking in the dark. A custom closed-loop experimental rig moved the refuge with gain proportional to the movements of the fish, suppressing or enhancing electrosensory feedback. There was a decrease in active sensing movements when electrosensory feedback was increased using a negative gain, and an increase in active sensing movements when sensory feedback was decreased using a positive gain. In this way, the fish alters the amplitude of its own motion in an inverse relation with experimentally imposed changes in feedback gain. Using this strategy, the fish maintains a fixed root-mean-squared error with respect to the refuge. This effect was also observed when controlling for the trajectory of the input stimulus, which was achieved using an open-loop playback experiment. These results indicate that fish adapt their active sensing motions in relation to the strength of sensory feedback.
