42.2 Thursday, Jan. 5 Gaining insight: visual feedback control in the hawkmoth Manduca sexta. FECHKO, AS*; HINTERWIRTH, AJ; DANIEL, TL; University of Washington; University of Washington; University of Washington firstname.lastname@example.org
Animals acquire and process sensory information to control motion in complex environments. In the hawkmoth Manduca sexta both visual and mechanosensory information are critical components of the flight control circuit. Visual feedback control, in particular, depends on a host of optical characteristics and upon the gain between the torque generated by a flying insect and the resulting movement of the insect’s visual field. To explore this relationship we built two coupled devices: (1) an optically based transducer that records torque produced by yaw motions in tethered insects and (2) a high spatial and temporal resolution (800 DPI, ~1kHz refresh rate) image feedback control system with a MEMS data projector. Using a custom C/OpenGL software platform, we control the relationship between the output of the torque sensor and the visual world presented to insects tethered in a flight arena. We specifically examined two questions: (1) to what extent does the feedback gain between torque and image motion determine an animal’s ability to track a visual stimulus and (2) to what extent can an animal adapt to different gains applied to the feedback loop? For 4 moths controlling their visual world with at least 4 different feedback gains in a minimum of 50 trials per moth we found that (1) individual moths have an optimal gain at which they best track image motion, and (2) the ability to track a visual stimulus improves after repeated exposure to the same gain and visual image slip. Interestingly, all moths tested were able to track image motion when the gain was reversed, suggesting significant plasticity in the visual flight control circuit.