A visual efference copy-based navigation algorithm in Drosophila for complex visual environments

How flies adjust their flight direction in response to visual cues has been intensively studied, leading to a detailed understanding of individual neural circuits. However, how these circuits operate collectively in complex visual environments remains unclear. To understand how a mixture of visual stimuli--including those caused by the flys own actions--jointly determines its motor program, we developed an integrative model of Drosophila visuomotor processing. In particular, we derived simple models from flies wing responses to individual visual patterns and combined them through different internal models. We compared the steering behavior of these "virtual flies" with those of flying flies that freely changed their orientation. The results of these experiments supported the idea that, for selective visual patterns, flies employ suppressive mechanisms between competing visuomotor reflexes, consistent with an efference copy-based internal model. Our model provides a formal description of vision-based navigation strategies of Drosophila under complex visual environments.