Data from: To keep on track during flight, fruitflies discount the skyward view

When small flying insects go off their intended course, they use the resulting pattern of motion on their eye, or optic flow, to guide corrective steering. A change in heading generates a unique, rotational motion pattern and a change in position generates a translational motion pattern, and each produces corrective responses in the wingbeats. Any image in the flow field can signal rotation, but owing to parallax, only the images of nearby objects can signal translation. Insects that fly near the ground might therefore respond more strongly to translational optic flow that occurs beneath them, as the nearby ground will produce strong optic flow. In these experiments, rigidly tethered fruitflies steered in response to computer-generated flow fields. When correcting for unintended rotations, flies weight the motion in their upper and lower visual fields equally. However, when correcting for unintended translations, flies weight the motion in the lower visual fields more strongly. These results are consistent with the interpretation that fruitflies stabilize by attending to visual areas likely to contain the strongest signals during natural flight conditions.小型飞行昆虫偏离预定航线时，会借助眼部感知到的运动模式——即光流（optic flow）——来指导飞行姿态修正。航向改变会产生独特的旋转运动模式，位置改变则生成平移运动模式，二者均会引发翅振的修正响应。光流场中的任意图像均可表征旋转，但由于视差效应，仅有近处物体的图像能够表征平移。因此，贴近地面飞行的昆虫对自身下方产生的平移光流响应会更为强烈，因为附近的地面会生成显著的光流信号。本实验中，研究人员将果蝇刚性束缚后，使其对计算机生成的光流场做出转向响应。当修正意外的旋转偏移时，果蝇对上下视野的运动信号赋予均等权重；但在修正意外的平移偏移时，果蝇会对下方视野的运动信号赋予更高权重。上述结果与“果蝇通过优先关注自然飞行状态下最可能携带最强信号的视觉区域以维持飞行稳定”的解读相一致。