Meeting Abstract
Animals moving in natural environments experience many simultaneous sensory cues. Visual scenes comprise task-relevant and irrelevant cues, and self-generated motion of the background. As vision research often uses salient widefield or target tracking cues, it remains unclear how animals parse multiple competing visual stimuli. Manduca sexta hawkmoths hover and track moving flowers. We explore how they contend with 3 types of external visual cues that may distract or aid in flower tracking: a stationary widefield cue, a stationary target (vertical bar) and an oscillating bar target. These cues may be ignored, linearly summed with the flower cue, or become distractors, which we assess as non-linear, context-specific effects on flower tracking. Figure/ground discrimination work in flies suggests that widefield cues may be processed independent of target motion, predicting no effect of the widefield cue on flower tracking. Linear dynamics typically capture moth flower tracking and describe the combination of multimodal sensory cues. We find that neither predicts the response to multiple visual cues. A stationary widefield cue improved flower tracking performance, decreasing tracking error at flower frequencies between 1.1Hz and 2.3Hz, where moths typically lag the flower and overshoot its position. In contrast, the oscillating visual cue did not impact flower tracking at any frequency except that of the bar, suggesting linearity. However, the specific gain and phase response at this frequency could not be predicted by linear combination or a rescaling of the bar stimulus. We conclude that given two distinct visual motion cues with differing task relevance, the signals combine nonlinearly to affect the primary task. Moths are distractible fliers, which may enable them to tune responses to cues in a context dependent way, for example to balance foraging and predator avoidance.
