A unified mechanism for innate and learned visual landmark guidance in the insect central complex
Fig 8
Persistence of direction in the absence of the landmark.
A. (a) Simulations are done in a static mode, i.e. the agent never leaves the center of the arena and only rotates around its vertical axis. (b) After the 2000th step the cue disappears. B. (a) We tested the model in the same configuration as before, where the landmark is used both as the main cue for the compass and to generate the directed behaviour (Fig 7C). Results are shown in C.a. (b) We tested another configuration where the compass was provided with cues from the absolute orientation in the environment (such as sun position or sky polarization could provide). The attraction behaviour is kept based on the landmark as before. Results are shown in C.b. C. EPG activity rate (blue to yellow) and relative landmark orientation (red line, right scale) during simulation of the cue disappearance paradigm showed in A. (a) The compass and the attraction are both based on the landmark (B.a). The direction can be maintained but slowly drifts as there is no external reference. (b) The compass is based on an absolute orientation perception (potentially from sky cues) while the attraction is based the landmark (B.b). Note this creates a potential offset in the position of the bump and the landmark, but the agent still moves towards the landmark. The heading can be accurately maintained when the landmark disappears.